Immobilization of single-stranded DNA onto fused silica and glass surfaces has been widely used for preparation of fiber optic sensors and DNA microarrays. Fundamental investigations of the orientation, motion and hybridization behavior of immobilized ssDNA is important to understand the design sensing devices. Using computational methods to evaluate molecular dynamics w have simulated a solid SiO₂-linker-ssDNA system and studied the conformations assumed by such immobilized material under different physical constraints. We have also evaluated the molecular dynamics of fluorescent intercalating dyes that are attached to the ssDNA by tethers of various lengths, with the goal of preparing a label on ssDNA that will transducer hybridization. Periodic boundary conditions were applied to examine packing properties and nearest neighbor interactions of adjacent ssDNA molecules. Molecular dynamics have been performed at room temperature as well as on heated systems. Solvent effects were taken into account and the modeling assumed the presence of an aqueous environment. The results suggest the various conformations and orientations that immobilized ssDNA can assume, and indicate that the orientation is generally far more that is perpendicular to the interface. Exploration of tether lengths indicates the minimum lengths that are required for a fluorescent label to operate efficiently as an intercalating agent.

Disposable electrochemical DNA-based biosensors are reviewed; they have been used for the determination of low- molecular weight compounds with affinity for nucleic acids and for the detection of hybridization reaction. The first application is related to the molecular interaction between surface-linked DNA and pollutants or drugs, in order to develop a simple device for rapid screening of toxic compounds. The determination of such compounds was measured by their effect simple device for rapid screening of toxic compounds. The determination of such compounds was measured by their effect on the oxidation signal of the guanine peak of calf thymus DNA immobilized on the electrode surface and investigated by chronopotentiometric or voltammetric analysis. Applicability to river and wastewater sample is demonstrated. Moreover, disposable electrochemical sensors for the detection of a specific sequence of DNA were realized by immobilizing synthetic single-stranded oligonucleotides onto a graphite screen-printed electrode. The probes because hybridized with different concentrations of complementary sequences present in the sample. The hybrids formed on the electrode surface were evaluated by chronopotentiometric analysis using daunomycin as the indicator of the hybridization reaction. The hybridization was also performed using real samples. Application to apolipoprotein E is described, in this case samples have to be amplified by PCR and then analyzed by the DNA biosensor. The extension of such procedures to samples of environmental interest or to contamination of food is discussed.

There are generally two kinds of DNA microarray used for genomic-scale gene expression profiling of mRNA: cDNA and DNA chip, but both of them suffer from some drawbacks. To meet more requirements, another oligonucleotide microarray with long was produced. This type of microarray had the advantages of low cost, minimal Cross-hybridization, flexible and easy to make, which is most fit for small laboratories with special purposes. In this paper, we devised different probes with different probe lengths, GC contents and gene positions to optimization the probe design. Experiments showed 70 mer probes are suitable for both sufficient sensitivity and reasonable costs. Higher G-C content produces stronger signal intensity thus better sensitivity and probes designed at 3 untranslated region of gene within the range of 300 pb should be best for both sensitivity and specificity.

In this research, a surface-plasmon resonance biosensor for nucleic acid detection was constructed, optimized and characterized. The kinetic response on hybridization was also studied. The biosensor was use as a platform for the study of the surface coverage control by single-strand or double-strand oligonucleotide immobilization. The dsDNA immobilization and offers a new way to surface coverage control for the nucleic acid biosensor construction.

Novel biotinylated molecular beacon (MB) probe was developed to prepare DNA biosensor using sol-gel chemistry. Biotinylated bovine serum albumin was encapsulated in the sol-gel matrix to form a biotinylated silica gel. Streptavidin acted as a bridge between biotinylated MB and silica gel. The MB based DNA biosensor can detect nonlabeled DNA target in real time with high sensitivity and one-base- mismatch selectivity, which indicated the potential applications in single point mutation detection. Compared with the previous report, the sol-gel based DNA biosensor has three advantages: (1). The response time was significantly shortened to 10 minutes when the cDNA concentration was over 10 nM. (2). The silica gel prolonged the lifetime of the MB based biosensor, which could keep its activity for thee weeks if stored in a buffer. (3) The gel formed by sol-gel method has a larger surface area than the common glass cover at the same scope. The number of binding sites for biotinylated increased significantly. Hence the detection limit was down to subnanomolar/L.

The PCR amplification is based on multiple temperature cycles of DNA synthesis; each includes denaturation of the template, annealing of the primers to complementary sites in the template and primer extension. The key technique of PCR amplification is the heating control in design and fabrication of its chip form. The specifications of the chip are heat properties. In this paper the heat properties of a micro PCR vessel integration heater and temperature sensor was introduced. The temperature distribution of the vessel was simulated with software tool IntelliSuite. The temperatures cycles were measured and the time response of the chip was discussed. It is found that the integrate micro vessel is a very useful tool not only for DNA synthesis but also as a biochemical reactor for many other biological and chemical analyses.

Reagentless biosensor that can directly transducer molecular recognition to optical signal should potentiate the development of sensor array fora wide variety of analytes. Nucleic acid aptamer can bind ligand tightly and specifically with conformational change of aptamer, and can be used as a receptor in biosensor. We have therefore developed a fiber-optic biosensor by aptamer connected with molecular beacon. Molecular beacons consist of an oligonucleotide sequence containing complementary sequence sections at either end. These two sequence containing segments base pair with each other to form a hairpin shaped loop structure, the fluorophore and quencher were attached at 5 foot- and 3 foot-end of molecular beacon respectively. When thrombin binding to the stem-loop of molecular beacon aptamer, the pseudoknot structure was interrupted, resulting a release of fluorescence from quenching and a increase in fluorescence emission. This novel biosensor system in this project has a large potential and is specific and sensitivity. A similar strategy could be used to study other analytes such as protein and small molecules.

In this article, we introduce a kind of capillary electrophoresis microchip in PDMS. This paper describes the procedure to design and fabricate channels in an elastomeric material - PDMS> The format of the capillary electrophoresis microchip is converted into a transparency, which serves as the photomask in contact photolithography to produce a SU-8 positive relief photoresist on silicon wafer. PDMS cast against the master yield s a replica contain ga network of channels, which are 200(Mu) m wide and 200micrometers deep. After the surface of this replica and a glass substrate being fabricated with the gold down-leads are oxidized in oxygen plasma, the two cured surfaces are brought into conformal contact and the capillary electrophoresis microchip is gotten.

We report gel-immobilized molecular beacon for DNA hybridization detection in this paper. The specially designed molecular beacons were covalently immobilized in polyacrylamide gel pads array. After hybridization, the complementary noncomplementary target can be easily distinguished with gel-immobilized molecular beacon probes. The results indicate the potential applications of this new gel-immobilized molecular beacon array in parallel, cost effective and label-free DNA hybridization detection.

The development of small molecules that can bind and recognize DNA with sequence- or stereo-specificity under physiological conditions has been attracting a great interest in chemistry and biochemistry. Here, spectroscopic characterization and gel electrophoresis methods have been utilized to investigate the DNA binding and recognition by a variety of binuclear transition metal complexes. The result indicate that the structures and charges of binuclear transition metal complexes, compositions of coordination spheres, central metal ions and their coordination unsaturation, and separations between two central metal atoms can exert significant effects on the DNA binding and recognition. If there are not intercalative ligands into DNA base pairs or kinetically substitutable ligands by DNA phosphate groups within coordination sphere, the coordination saturation and compact binuclear transition metal complexes weaker bind to DNA than the coordination unsaturation and extended ones to DNA. Since the different transtiometal ions exhibit different affinities to DNA phosphate oxygen atoms, the binding interactions between their binuclear complexes and DNA are controlled by the affinity. He binuclear complexes with one or more negative charges lead to a consequence that they can not efficient associate with DNA, because DNA phosphodiester backbone is negatively charged. Whenthe separations between two central transition metal atoms is more than the distance between two DNA base pairs, the binuclear complexes could bind and recognize the DNA sequence with two or more base pairs. The protonated and positively charged ligands can strengthen the DNA binding and recognition by these binuclear metal complexes. Based on such DNA binding and recognition principles, the binuclear zinc complex designed in the study preferentially bind and recognize the following DNA sequence on pBR322 DNA with binding constant K.

This paper details the principle of DNAFET which is made up of ISFET and a nucleic acid membrane. Here the immobilization method with an Avidin-Biotin complex directly on the surface is used in DNAFET. The measurement of DNA hybridization experiments illustrates the usefulness and potential of the DNAFET.

The anti-thrombin aptamer can recognize and interact with thrombin in high affinity. This interaction results in the change of the fluorescent anisotorpy in the solution of the aptamer labeled with fluorescence. We developed a new method based on the change of the fluorescent anisotropy intensity resulted from this interaction. The change in polarization was depended on the concentration of thrombin. The linear range of the determination is 0.1-100ng/ml. The detection limit for thrombin is 0.1 ng/ml. This method has been used to determine thrombin in human whole blood. Aptamer that change the fluorescence characteristics of attached fluorophore will be useful in noncompetitive fluorescence polarization assay.

Luminescent assay for detection ATP is very sensitive with limitation of 10^-17 moles. ATP using styrene oxide as a model carcinogen we currently apply a luminescence technique to detect the very low levels of carcinogen-DNA adducts in vitro and in vivo. The bioluminescent assay of DNA adducts entails three consecutive steps: digestion of modified DNA to adducted dinucleoside monophosphate and normal nucleotide are hydrolyzed to nucleosides (N) by nuclease P1 and prostatic acid phosphomonesterase (PAP); incorporation of (gamma) -P of ATP into normal nucleoside(N); detection of consumption of ATP by luminescence. This assay does not require separate manipulation because of the selective property of nuclease P1. One fmol of carcinogen- DNA adducts was detected by luminescent assay. A good correlation between results of luminescent assay and ³²P-postlabeling procedures has been observed. We detect 1 adduct in 10⁸ nucleotides for 10(mu) g DNA sample. The procedures of luminescent method is very simple and low- cost. IT appears applicable to the ultra sensitive detection of low levels of DNA adducts without radioactive isotope.

There are three parts in this paper. In the part 1 nitric oxide chemistry and the measurements of nitric oxide in biological models have been reviewed. In the part 2 the channels and collateral sand modern studies of the channels and collaterals have also ben reviewed and in part 3 a NO biosensor has been developed and it has been applied in the research of the channels and collaterals. Research results have confirmed that NO plays an important role in channel transmission.

Electrically monitored lipid bilayer membranes, protected form mechanical damage and contact with low-energy liquids by a hydrogel layer, show promise in biosensing applications. We describe the principle and implementation of a bipotentiostatic circuit for the measurement of both resistance and capacitance of gel-protected membranes. We report measurements taken using the bipotentiostat of membranes formed using glycerol 1-monooleate, and the response of these membranes taken using the bipotentiostat of membranes formed using glycerol 1-monooleate, and the response of these membranes to the ionophore, valinomycin.

At the Symposium on the Plasma Membrane in 1961, when a group of unknown researchers reported the reconstitution of a bimolecular lipid membrane in vitro, the report was met with scepticism. Those present included some of the foremost proponents of the lipid bilayer concept, such as Davson, Danielli, Stoechenius, Adrian, Mauro, Finean, and many others.

Bilayer lipid membranes (BLMs) are promising 'smart' materials for biosensor and biomolecules. A novel pH-microbe of an acupuncture needle support with BLM modified by electron mediators was fabricated. An intelligent biosensor system BLM-based was developed. The intelligent system can automatically measure and analyze pH value of aqueous solution with probes BLMs-based and Si-chips thin-film as sensing elements. It can also give a warning message when the pH value of aqueous solution is over one threshold value. The intelligent system has communication interface of computer. A monitoring system based network can be constructed by connection the intelligence system with computers.

An important biosensor application is the continuous monitoring blood or tissue fluid glucose concentration in people with diabetes. Our research focuses on the development of a glucose sensor based on potentiostatic oxygen electrodes and immobilized glucose oxidase for long- term application as an implant in tissues. As the sensor signal depends on many design variables, a trial-and-error approach to sensor optimization can be time-consuming. Here, the properties of an implantable glucose sensor are optimized by a systematic computational simulation approach.

A new method employing a combination of micro dialysis sampling and chemiluminescence reaction was developed to monitor nitric oxide (NO) in vivo. A special probe was designed with an interference-free membrane to achieve a very high selectivity for NO. High sensitivity was achieved by optimizing the working system and improving the NO sampling time. This system was used in vivo to monitor blood and brain tissue in rats and rabbits. We have established that this system is sensitive enough to detect variations in NO production in difference physiological state. The system can detect NO in the linear range of 5nM-1(mu) M, with a detection limit of 1nM, and real NO concentrations in our experimental animals were found to be in the range of 1-5 nM or even less. Finally, the effects of body temperature, NO donors, Viagra, NO activators, NO cofactors, NO interference were investigated carefully in different physiological situations.

To develop an immunoassay and further an immunosensor for 2,4-D based upon recombinant antibody, the Fab fragments of 2,4-D specific antibody were expressed in E. coli. Western blotting analysis of the periplasmic cell fractions shown that under the non-reducing condition only a single protein band at a molecular mass of 45-kDa, corresponding to the whole Fab fragment was detected. Antigen binding activity for 2,4-D was found only in the extract of cells bearing the 2,4-D plasmid. An immunoassay based on the competitive reaction of 2,4-D and enzyme tracer with 2,4-D Fab fragments immobilized on micro titer plates via rabbit anti-mouse IgC was developed. Using this assay, 2,4-D could be detected at concentration range of 0.5 (mu) g/1 to 10(mu) g/1. The center point of the 2,4-D test was found at a concentration of 5 (mu) g/l. The assay was applied for detection of 2,4-D in spiked orange samples, resulting in recovery rate of 90 percent. The immunoassay could be applied to monitor human exposure to 2,4-D from contamination in fruit samples.

Electrochemical microsensors have been applied in the field of biomedicine for many years. The aim of this work was to develop a novel oxygen sensor to monitor the partial pressure of oxygen in tissues and acupuncture points. The functions of microsensor were evaluated through in vitro experiments. In vivo in tissues and acupuncture points. The data from oxygen microsensor were compared with the data from blood gas analyzer. The measurements depend on the physiological changes of experimental animal. The further development of this new sensor is to be a tool for meridian research.

An immunoreaction of human immunoglobulin G and goat anti- human immunoglobulin G was real-time tested by a novel SPR biochemical analytical system. Data for direct binding of IgG and immunoreaction between IgG and GAH IgG was presented, also the SNR of this system was calculated. The SPR chip gold surface prepare method was discussed.

To investigate the relation between biosensor of endotoxin and endotoxin of plasma in sepsis. Method: biosensor of endotoxin was designed with technology of quartz crystal microbalance bioaffinity sensor ligand of endotoxin were immobilized by protein A conjugate. When a sample soliton of plasma containing endotoxin 0.01, 0.03, 0.06, 0.1, 0.5, 1.0Eu, treated with perchloric acid and injected into slot of quartz crystal surface respectively, the ligand was released from the surface of quartz crystal to form a more stable complex with endotoxin in solution. The endotoxin concentration corresponded to the weight change on the crystal surface, and caused change of frequency that occurred when desorbed. The result was biosensor of endotoxin might detect endotoxin of plasma in sepsis, measurements range between 0.05Eu and 0.5Eu in the stop flow mode, measurement range between 0.1Eu and 1Eu in the flow mode. The sensor of endotoxin could detect the endotoxin of plasm rapidly, and use for detection sepsis in clinically.

Peroxynitrite is an important derivative made by nitric oxide in vivo. It can make damages in many kinds of tissue and cells. Its research value in heart disease and cancer is a very high. A sensitive, specific method for analysis of peroxynitrite is described. In this method, chemiluminescence reaction between perodynitrite and luminol was used to detect with flow injection system. The assay has a detection limit of 2 by 10^-8 mol L^-1, and linear range of 5 by 10^-8 mol L^-1 to 5 by 10^-5 mol L^-1. The application o f flow injection system offers the possibility to establish biosensor for real-time detection of perodynitrite.

We investigate the possibility of increasing sensitivity of TRAP assay by aptamer.

In this research, a near-IR fluorescent labeled nucleic acid conjugate for the nucleic acid detection was synthesized, and characterized preliminarily for the detection of the nucleic acid. Th conjugate combines the molecular recognition properties of the oligonucleotides with the near-IR fluorescence label PR646. Both single- and dual- labeled conjugates were studied for their hybridization with the complementary nucleic acid. The dual labeled conjugate has indicated that the self-quenching effect exists in ssDNA form while the fluorescence increases greatly after hybridization with the complementary nucleic acids. The time-resolved fluorescence was also studied.

Calcium ion is a very important messenger not only between cell and cell, but also in meridian main and collateral channels. A new neutral carrier PVC membrane based needle- type potential sensor was prepared, which shows a good selectivity for Ca²⁺. Response characteristics, pH, response time of sensor, other metal ions such as Mg²⁺, Na⁺, and K⁺ in measuring calcium ion were investigated. The resulting sensor has a liner range from 1.0 X 10^-6 to 9.1 X 10^-3 mol. L. The sensor will be used in the detection of Ca²⁺ in vivo in muscular tissues of the mice.

The luminous intensity of dark variant separated form photobacterium phosphoreum is 1/10000 less than that of wild-type. Ethidium Bromide (EB), Mytomycin C(MC), 2-amino fluorine can all strongly induce reversion mutation for S1 within 24h and increase reversion ratio significantly. The results of experiments indicated that these revertants have stable genetic character and the mutation may take place at gene levels. The mutagenesis to S1 caused by EB, MC and 2-AF was detected and it may be a new rapid, simple and sensitive method of gene toxicant monitoring.

How to monitor meridian in human body is a problem remained to be solved. It is found out form more and more medical experiments that there is obvious different between meridians and the control points of non-meridian tissues in some activities of biochemical index. The difference is particular remarkable when they are punctured. The method discussed in the article is based on the difference. In order to analyze the characteristics of the non-linear dynamics, traditional Chinese-medicine-sensor are developed to obtain the messages form human body meridians and the control points of non-meridian tissues. At the same time, the technique of fusing information from multisensor is adopted to acquire synthetic features that serve as the basis of meridian recognition. And therefore a new method and basic technique are established for recognizing meridian for the first time.

Until recently, molecular beacons were limited to detecting nucleic acid target. Here we present a new technology for detection of thrombin protein by aptamer-derived molecule beacon without any antibody. A aptamer anti-thrombin was used as a recognition molecule. To make aptamer molecular beacon, we constructed two DNA oligomers that are derived from the aptamer to thrombin. To one of the DNA oligomers that forms a hairpin structure, the fluorophore and quencher were attac3hed at the 5 foot and 3 foot ends, respectively. Specially in the presence of Tat or its peptides, but not in the presence of other proteins, the two ligometers undergo a conformational change to form a duplex that leads to relieving of fluorophore from the quencher, and thus a significant enhancement of the fluorescence of fluorescein was observed. A novel strategy for exploiting aptamers in the analysis of thrombin has been described. A similar strategy could be used to study other analytes such as proteins and small molecules.

Detection dioxins-type chemicals by a sensing cell line containing luciferase reporter gene under the control of dioxin responsive elements was compared with the traditional ethoxyresorufin O-deethylase (EROD) induction. The result suggested that the luciferase induction was 30-fold more sensitive than EROD induction, the detection time was shorter for 68-hour and the detection procedure was also simpler. The data showed the sensing cell line can screen lots of samples and quickly semi-quantitate.

A new instrument for the determination of low concentrations of nitrite is presented. Nitrite reacts with I^- in acidic medium to form nitric oxide that is subsequently removed from reaction solution by scrubbing with argon gas, then nitric oxide is detected by Luminol/H₂O₂ Chemiluminescence detection. The detection limit of nitrite is 10pmol for S/N equals 3. The calibration graph is linear up to 1000 pmol. The coefficient of variation for 500pmol nitrite in samples is 4.87 percent. Analysis time for single test is 250 S. The results are in good agreement with a spectrophotometric interfering ions and has been applied to the analysis of a variety of biological samples.

With the persisting increase of drug-resistant stains of M. Tuberculosis around the world, rapid and sensitive detection of antibiotic of M. Tuberculosis is becoming more and more important. In the present study, drug susceptibility of M. tuberculosis were detected by recombination mycobacteriophage combined with bioluminescence sensor. It is based on the use of recombination mycobacteriophage which can express firefly luciferase when it infects viable mycobacteria, and can effectively produce quantifiable photon. Meanwhile, in mycobacterium cells treated with active antibiotic, no light is observed. The emitted light is recorded by a bioluminscence sensor, so the result of drug-resistant test can be determined by the naked eye. 159 stains of M. tuberculosis were applied to this test on their resistant to rifampin, streptomycin and isoniazid. It is found that the agreement of this assay with Liewenstein- Jensen slat is: rifampin 95.60 percent, isoniazid 91.82 percent, streptomycin 88.68 percent, which showed that it is a fast and practical method to scene and detect drug resistant of mycobacterium stains.

Using quartz fiber-immobilized laccase, detection of catecholamine neurotransmitter is described in this work. Laccase is immobilized on the fiber-optic by means of 3- aminopropyltriethoxysilane/glutaraldehyde method. The oxidation products of adrenalin catalyzed by laccade would absorb the fiber-optic evanescent wave according to the products' concentration. The optimal detection range of this fiber-optic biosensor is between 50-250ng/ml. The minimum detection limit is 10ng/ml. The analysis can provide results in only two minutes to detect one sample. Finally, the specificity of the biosensor is high. The special interference of other substrates of laccase such as o- phyenylenediamine (OPD) and benzenediol can be removed by controlling the pH of the reaction buffer. When the OPD concentration is 100ng/ml, the relative error is only 6.3 percent. On the other hand, the non-special interference is removed by employing double-channel differential method.

A L-lactate oxidase (LOD)-based biosensor is developed for the determination of L-lactate in blood samples. The L- lactate oxidase membrane is prepared by covalently linking LOD into a nylon set, followed by attaching the membrane onto a flow injection type of oxygen electrode. The response of the biosensor is based on the limited diffusion of L- lactate on the L-lactate oxidase membrane. No performance difference have been found between the LOD-based biosensor and regular enzyme optical determination methods for blood sample testing. It is suggested that the LOD-based biosensor may serve as an alternative for the detection of L-lactate in blood.

A novel biosensor for assaying anticancer drug cyclophosphamide was constructed with salt-bridge supported bilayer lipid membrane modified with tetraphenylborate- cyclophosphamide complex. The modification was achieved by the introduction of the complex into the membrane forming solution. The biosensor show a linear response to the drug over the concentration range 8.96 X 10^-6 mol L^-1. The effects of coexistent substances and pH on assay were evaluated. The results show that the distinguish merits of this kind of biosensor is the excellently biological compatibility and no need of mediator for ions exchange. It also shows good selectivity and sensitivity for cyclophosphamide assay.

A new bis-poporphyrin based fluorogenic reagent was synthesized and used in selective histidine recognition based on intramolecular photo-induced electron transfer.

Thermally and non-thermally biological effects of IR lights absorbed have been studied by nonlinear quantum theory and molecular biology on the basis of structures of cell and protein molecules. The mechanism of thermally biological effect is that the IR lights absorbed cause the quantum vibrations of bio-water molecules with hydrogen bonds. The vibration energy can transform as thermal energy of disorder motions of the water molecules according to its features of structure. The heated waters can cause a series of biological effects and phenomena to occur in the living system. The mechanism of the non-thermally biological effect is the follows. The IR lights absorbed can cause the quantum vibrations of amide-I in protein molecules, the vibrational quanta become as solitons by the self-trapping mechanism. The soliton carried energy can transport to one place from the other to generate a lot of biological effects. Also, the IR light scan also participate a lot of bio-chemical reactions. This is a non-thermally biological phenomenon.

Interference caused by ascorbic acid has been one of the most frequently encountered problems in the design of amperometric biosensors. The accuracy of the nowadays well- commercialized amperometric blood glucose monitor is still more or less affected by the fluctuation of ascorbic acid level in blood. The interference of ascorbic acid is serious and widespread.

Electro chemiluminescence is a form of chemiluminescence in which the light emitting reaction is preceded by an electrochemical reaction. The ECL reaction of an acridan ester is described as an example. With this kind of reaction of the advantages of CL are retained, but the electrochemical step allows the time and position of the light emitting reaction to be controlled. By controlling the time of the reaction light emission can be delayed until levels such as immune or enzyme catalyzed reactions have taken place, and by controlling the position light emission can be confirmed to a region that is precisely located with respect to the detector, improving sensitivity by increasing the ratio of signal to noise. The advantages will be highlighted by describing an enzyme ECL immunoassay for small molecules such as dinitrophenol, in which superparamagnetic bead technology is used to concentrate enzyme labeled antibodies on the surface of an electrode, in close proximity to the detector. Finally the future of research in this are will be examined by describing how bipolar electrodes can be used to free ECL from the constraints imposed on it by conventional 2D electrodes.

The anion sensing properties of potentiometric sensors prepared by formation of 50 micrometers layer of epoxy resin on a metallic silver support have been examine. Experimental work was carried out for three different resins of various origin commercially available. For all examine resins the sensitivity of potentiometric sensors was examined for 14 different inorganic and organic anions in micro- and milimolar range of concentration. A range of linear response, slope of response, reproducibility of functioning and response time was examined for each measuring ion. In a large majority of tested cases the slope of the calibration curves for both mono- and divalent ions was very close to Nerstian ones, with deviations sporadically exceeding g10 percent. In almost all cases the linearity range of response was found down to 10 (mu) M level of concentration. Response time of epoxy resin sensors to anions is similar to that observed for common solid-state membrane electrodes. For concentration change between 1 and 10 mM the 95 percent of steady-state response was obtained within 30 to 90 s depending on the kind of resin. The selectivity of potentionmetric response is significantly different fro examine resins. The observed selectivity pattern in each case is different than typical one according to lipophilicity of sensed anions or free energy of hydration that is exhibited by conventional ion-exchangers with anion exchange ammonium groups.

Planar microelectrochemical chips with thin film electodes of different shapes and arrangement, have been developed and fabricated. Micro electrochemical cell with closely vertically spaced electrodes allows to exploit the effect of redox recycling and an increase of collection efficiency for a high current amplification. PC simulations of electro- mechanical properties of sl-BLM is useful tool for evaluation and prediction of BLM behavior. Non-symmetric microelectrode arrays were designed and fabricated for electrical monitoring of human skin.

The direct electrochemistry of flavin-containing monooxygenase, pentachlorophenol hydroxlase (PCPH), has been investigated under a variety of conditions. PCPH underwent a two-electron process on the electrodes, which correspond to the reduction/oxidation of FAD/FADH₂ within the enzyme. The electrochemical response of PCPH relies on the interface of the electrode and the enzyme solution. Three types of interaction of the enzyme molecule with the electrodes were observed: at a bare edge-plane graphite electrode, diffusion-controlled process was observed, suggesting the interaction is weak. In the presence of the cations, the interaction became stronger, so that the voltammetric response changed from a diffusion control to an adsorption control An intermediate case was observed at a poly(L- lysine) modified EPG electrode.

The main performance of the aluminum-electrolytic capacitor depends on the quality of the anodic oxide firm used as dielectric, which lies on the form capacity of the form- electrolyte. Therefore, it is very important to measure the form capacity of the form-electrolyte. However, the method, at present, cannot scale the capacity of it. We bring forward expressions that use to measure the electrolyte's form capacity according to the equivalent circuit of the oxide firm in the literature. We found the method is right by a great deal of experiments in different temperatures and concentrations of the electrolyte. Moreover, the measure only needs a circuit control system.

In this paper, a kind of amperometric sensors for simultaneous determination of Cd²⁺ and Pb²⁺ was investigated. Cd²⁺ and Pb²⁺ are firstly deposited on the surface of the sensor at -1.20 V and then reduced. In the following step, reduced Cd and Pb are oxidized by scanning the potential towards a positive direction. The experimental parameters, which influence sensitivity and detection limit, such as supporting electrolyte and pH values, accumulation potential and accumulation time, scan rate, were examined. The mechanism as to the voltammetric response of this sensor was discussed. This sensor has following advantages: easy and convenient fabrication, low cost, low detection limit and fast response. The detection limits are 5 X 10^-11 mol/L for Cd²⁺ and 8 by 10^-11 mol/L for Pb²⁺.

A novel method of synchronization of separation and analysis is described, which use the mode-filtered light detection as an on line detector of capillary electrophoresis, furthermore, corresponding to this method an instrument has been established. Capillary electrophoresis runs in an annular column, which is constructed by a naked optical fiber inserted into a fused silica capillary, instead of a round capillary, instead of a round capillary. Moreover, the annular column is not only a vessel for electrophoresis but also a sensor to the mode-filtered light. Along the annular column side several detection channels are set up to gather the mode-filtered light and transmit it to CCD, so every channel provides the information of the sample form where it is located. Using the capillary isotachophoresis in this annular column, a sample containing alanine and glycin is separated and analyzed simultaneously by the multi-channel mode-filtered light detection.

On the basis of character of work function shift caused by the interaction of pure or hybrid indium oxide with ozone, we developed ozone sensor with HSGFET operating at room temperature. And analyzed the response character of the samples.

The WO₃ thin films were prepared by magnetron sputtering method on the 3mm by 3mm silicon substrates with Pt interdigitating electrodes and heater. The deposition and the operating temperatures were analyzed to optimize the technological parameters. The sensing properties of these films to NO₂ gas were measured. The result indicate that the sensitivities are strongly dependent on the deposition and operating temperatures. The WO₃ thin film deposited at 300 degrees C and then annealed in air at 600 degrees C for 4h shows the excellent sensing properties to NO₂ gas at the operating temperature of 250 degrees C.

In accordance with different UV light absorption between oil and water, oil concentration in water is measured by using GaN UV sensing detector. The experiment has shown that it is a simple, quick, sensing and promising method.

FEA modeling of a thermally-excited silicon beam resonant pressure sensor is presented. The sensor consists of two bonded silicon chips, one with an etched beam and another with an etched diaphragm. FEA modeling is carried out on temperature distribution, resonant frequency shift due to thermal stress, effect of heater/detector elements on the natural resonance frequency, design of diaphragm geometry, and sensitivity of pressure measurement. The resonant pressure sensor samples are realized by silicon micromachining are measured. There is a satisfactory agreement between theory and experiments.

A new concept of gas pendulum is put forward in this paper. Buoyancy lift and the pendulous character of gas flow, the analogy between gas pendulum and solid pendulum, and the gas pendulum accelerometer and tilt sensor are discussed.

A swimming microrobot driven by magnetic field is presented. A new smart material, ferromagnetic polymer was utilized as actuation material. The microrobot has a pari of FMP fins, which are soft and driven by magnetic field symmetrically. The principle of actuation is given. The size of the robot is 20mm by 14mm by 5mm. The robot can move forward and backward dependent on the magnetic flux density and the frequency. The robot has many possible applications, such as minimally invasive medical techniques.

Several techniques used to improve the characteristics of self-excitation vibrating-wire sensor are summarized. First, the new mathematical model and its applications are given. Then, the match of wire and diaphragm for the horizontal wire type sensor to reduce the hysteresis of the sensor is presented. After that, the weak excitation of the wire is stated, which can effectively solve the problem of frequency variations. At last, the techniques of piston-conveying pressure and force conversion can be used to enhance the accuracy and long-term stability of wide range pressures sensors and force sensors.

Micromachined microwave coplanar waveguides were fabricated in standard CMOS technology and the hybrid etch technology. The coplanar waveguides have been suspend from the silicon substrate and third insertion loss was greatly improved. When fabricating the micromachined structures on a (100) wafer, stress was relaxed because of the different thermal expansion coefficients between silicon and SiO₂ dielectric. This caused this structures deformed. Among all etching pattern we had adopted, the etching orientation along the (100) line of the wafer obtained the smaller stress relaxation, but costing the longest etching time. ON the other hand, the space between the open areas for etching needs to be designed carefully to obtain the best mechanical and electrical properties.

This paper proposed a novel application of the multi Light- Addressable Potential Sensor (mLAPS) for multi-parameters and biochemical imaging detection which advantage was its short time to take a multi-parameters and image of the surface potential distribution along its surface By illuminating the LAPS simultaneously at several positions, of which each was illuminated with a light pointer modulated with a different frequency, the surface potential at all illuminated regions can be measured simultaneously by analyzing the resulting photocurrent. By using this method, the rate to obtain a complete image of the surface potential distribution by scanning the surface with one single light pointer. According to the result obtained in this report, the mLAPS should be an interesting and realizable device.

A surface micromachined miniature switch has been made on silicon substrate using an electroplated gold micro-beam as the cantilevered arm, a chromium-to-gold electrical contact, and electrostatic actuation as the switching mechanism. The switch has an electrical isolation of -30dB in the 'off' state and an insertion loss of 4-7dB form 1 to 10 Ghz with a return loss of -15dB in the 'on' state. The high insertion loss has attributed to generation of parasitic current in low resistivity of the silicon substrate.

We simulate the structure of surface MEMS RF switch by suing ANSYS electrostatic and mechanical energy coupled analysis with established models. In this paper actuation voltage for different geometrical scales of suspended beam contacted switch are discussed. The dependence of actuation voltage on the Yang's module, size of cantilever and electrode area is calculated.

In this paper a new type of large displacement eddy current sensor is developed to overcome the three main disadvantages of the traditional eddy current senor. For a traditional sensor, the measurement range is limited and less than one half of the diameter of the measuring coil. The output is high sensitivity to the changes of the target material and the cable length connected between the probe and the preamplifier. When the material or the cable length changed, it is necessary to readjust the preamplifier. The probe of the new eddy current sensor has three coaxial measuring coils, one is an exciting coil and the other two are receiving coils. The diameter of measuring coils is (Phi) 11 mm. The measurement range of this sensor is 40mm and almost four times of the diameter of the coil. The form of differential input and feedback amplification is used in signal amplifier. Thus the effect of the common modules, such as the changes of the target material and the cable length, can be counteracted well.

Love wave is one type of the surface acoustic waves (SAWs). It is guided acoustic mode propagating in ta thin layer deposited on a substrate. Because of its advantages of high mass sensitivity, low noise level and being fit for operating in liquids, Love wave acoustic sensors have become one of the hot spots in the research of biosensor nowadays. In this paper the Love wave devices with the substrate of ST-cut quartz and the guiding layers of PMMA and fused quartz were fabricated successfully. By measuring the transfer function S₂₁ and the insertion loss of the devices, the characteristics of the Rayleigh wave device and the Love wave devices with different guiding layers in gas phase and liquid phase were compared. It was validated that the Love wave sensor is suitable for testing in liquids but the Rayleigh wave sensor is not. What's more, SiO₂ is the more proper material for the guiding layer of the Love wave device.

A novel four-eyes robust optical fiber distance and orientation measuring integrated proximity sensor is presented in this paper. The transducer can measure the distance and orientation of the objects surface at the same time, and is insusceptible to the fluctuation of the optical power output and variation of the object surface's reflectivity. The transducer's measuring attitude control is one of the important content studied in this paper. Based on the prior research, which verifies that the measuring pose does exist and there is only one such attitude, further study on optimize the attitude adjusting control is done to improve the systems real time performances. In view of the complexity of the transducer's mode, an improved BP neural network data processing method is proposed to solve the difficulty in real time data processing. By partition the multi-output BP network into several single output ones and subsection the range of input variables, the sensor's accuracy of pose estimation is significantly increased.

The development of DSP has greatly promoted precision and intelligence of industry instrument. This paper introduces a kind of diesel valve diagnoses instrument based on Dual-MCU, TMS320C31 and AT89C52. The instrument measures vibration signal of diesel cylinder header, extracts the characteristic parameters, diagnoses fault of leakage and abnormal clearance of valve. This paper deals in detail with the general structure and function of every part of the diagnosis instrument as well as the structure and design of software for diagnosis.

A monolithic triaxial accelerometers based on thick-film technology is presented, and its structure and operating principle are discussed in this paper. Design and fabrication for the accelerometers are described together with theoretical predications and FEM analysis. The sensing elements on elastic membrane were analyzed in particular by COSMOS/M FEM and its geometric structure parameters were optimized. The overall performance of the device suggests that with proper control of screen-printing and firing processes, many applications in advanced industrial requirements will be possible in the near future.

A new optical voltage transformer is designed based on the Pockels electro-optic effect of the crystal Bi₄Ge₃O₁₂ (BGO). Here, the reflection-type longitudinal modulation Pockels cell is described in detail. The longitudinal Pockels effect is called the quadrate electro- optic effect. The electric field could modulate the Polarization State of light as it passes through the transparent material. The optical output of the sensor is a closed quadrate to the electric field, which is performed by means of a digital signal processors. The processing algorithm accounts the optical fringes of the quadrate signals and produces a smooth and continuos reconstruction of applied voltage by using portions of the quadrate signals for interpolation. The technique works equally well regardless of whether the measured voltage is sinusoidal distorted.

It has been proven that the saturation magnetostrictive constant (lambda) s of TbDyFe single crystal is 10-50 times larger than the coefficient of conventional magnetostrictive materials. In this paper bulk TbDyFe single crystal was prepared, completely without contamination, via Hukin's magnetic levitation cold crucible in Czochralski techniques. By adopting the TbDyFe single crystal as Magneto-sensing unit, a displacement sensor with high resolution was developed. Its structure and principle was described as follow: the sensor consists of measurement head, magnetostrictive driver and closed loop control system. The measurement head, with having giant resolution, ca determine the distance between the sample and the magnetostrictive driver in a suitable range. Whenthe sample shifts, the measurement head gives the closed control system a back signal that makes the magnetostrictive driver corresponding shift, leading to same and magnetostrictive driver in a suitable range. For the character of magnetostrictive driver being known, the shift can be measured via the control volume of magnetostrictive driver.

In this paper, several micro-mechanical structures of high g-force MEMS accelerometers will be analyzed; their characteristics will be discussed. Finally, a structure with new features will be given.

In this paper, a CMOS compatible process for high sensitive silicon micron microphone has been proposed. Corrugated diaphragms have been introduced to reduce the initial stress. A MOS preamplifier with very high input impedance can be integrated in the same chip to meet the requirement on high output sensitivity, low power consumption and minimization. As a matter of fact, the polysilicon of the composite diaphragm can be patented as resistors and gates of MOSFET. All the CMOS process steps except the N well implantation and drive in can be placed after the microphone fabrication. This process is simple, efficient and seems very promising for future miro-acoustic systems.

Piezo resistive silicon accelerometers have many excellent performance characteristics such as high sensitivity, high reliability and low cost. In this paper, a novel Piezo resistive silicon accelerometer is presented. This accelerometer has four beams. Such structure can not only decrease cross-axis sensitivity, but also utilize the full of strain caused by acceleration. Using Finite-Element Analysis (FEA) software, we did strain simulation in order to analyze the stress distribution. The result of finite- element method simulation accorded with theory analysis very much. Layout design and fabrication process result of finite-element method simulation accorded with theory analysis very much. Layout design and fabrication process of this accelerometer are presented in this paper, also, During fabrication process, a novel double side alignment was introduced. We also changed the release process of the sensor proof masses. This can make reject rate become very small.

It has been found through a large amount of experimental measurements that the differences of blood pressure among the four limbs are highly correlated with hyperlipemia thrombosis, blood vessel hardening and high density of blood in supine position. The prototype of the synchronous sphygmomanometr, which developed based on the above results, has been successfully test on hundreds of patients in many hospitals and sanatoriums.

Introduction of a portable digital multi-function device, which acting as vacuumeter, atmospheric pressure altimeter, thermograph and manometer as well.

Several kinds of sensors are installed in the robotic gripper. According to the outputs of multi-sensor, a data fusion technique is utilized to ensure the robot walking or grasping objects safely and reliably. In this paper, sensors of the gripper are introduced, such as force sensor for contact sensing and gripping force control, proximity sensor for collision prevention and position detection, and a displacement sensor for gripper openness control. The experiments of grasping objects with the gripper are presented, including firm grasp, virtual grasp, skew grasp, empty grasp and so on. The accurate information of grasping objects with the gripper is obtained using the multi-sensor data fusion technique based on the BP artificial neural network.

The humidity sensors were made of the composite material of nano crystal BaTiO₃ and polymer RMX. The complex impedance diagrams of the composite material were drawn in the frequency range 10Hz-100kHz, and in the relative humidity range 7 percent to 98 percent at the temperature around 15 degrees C. As the RH increases, the shape of the complex impedance curves changes from a semicircle to a line.

A new p+) (pi) n⁺ structure of silicon magnetic device is designed, using Lampert model and the Ashley- Milnes Space-Charge regime model analyzed double injection space-charge-limited current negative-resistance characteristic in p⁺ (pi) n⁺ structure of silicon magnetic device. Some useful approximate formulas and experimental results are also presented. The analysis gives results which closely represents practical situations.

There are two phenomena appear when charged particles enter the metal measuring pipe. One is triboelectricity and the other is charge leakage. The paper describes the effects of two phenomena on the measuring pipe potential in detail, and presents an optimal mathematical model of measuring space density of charge in pneumatic pipeline in real-time.

This paper related the structural principle and property of piezoelectric quart tilt meter. The tilt meter used symmetric support structure and differential frequency output had distinguish ability 0.0014 degrees, no linearity 0.13 percent and response time less 50ms.

This paper presents the theoretical investigation, design, fabrication, package and experimental measurement of a novel vacuum microelectronic (VME) pressure sensor. A new configuration, named 'cathode-on-membrane', greatly reduces the difficulties in the package process and enables practical VME pressures sensors to be developed. Computer simulation and computer aided design have been used to theoretically investigate the properties of the sensor and to optimize its structure. Experimental studies and results are reported, for the first time, revealing the characteristics of the sensor output current varying with applied pressure under different anode voltages.

This paper describes techniques for improving the accuracy and stability of the optical voltage transformers (OVT), which are affected by temperature around circumstances. Higher accuracy and stability is achieved by two light- channels compensation method, which uses one polarizing beam splitter. Many test show that this compensation method can eliminate the effects of unwanted birefringence induced by temperature and around circumstances of OVT effectively. OVT which uses this compensation method has passed the type test with accuracy and stability within +/- 2 percent.

A correction method for non-linear Pt resistance temperature measurement based on the principle of A/D conversion is introduced. The design principle of Pt resistance linear temperature measurement is analyzed and a new method for interfacing A/D converter with single chip computer 89c52 is provided together with the experimental data.

Presented is the characteristic of In-System Programmable PLD. Analyze the working principle of solid-sate energy meter, and design the digital circuit of single-phase energy meter. As a result, the basic solid-state meter design will be more accurate, more reliable, and cheaper than electro- mechanical meters.

This paper reports on a research effort to design, microfabricate and test an optical fiber display switch based on magneto hydrodynamic (MHD) principal. The switch is driven by the Lorentz force and can be used to turn on/off the light. The SU-8 photoresist and UV light source were used for prototype fabrication in order to lower the cost. With a magnetic field supplied by an external permanent magnet, and a plus electrical current supplied across the two inert sidewall electrodes, the distributed body force generated will produce a pressure difference on the fluid mercury in the switch chamber. By change the direction of current flow, the mercury can turn on or cut off the light pass in less than 10 ms. The major advantages of a MHD-based micro-switch are that it does not contain any solid moving parts and power consumption is much smaller comparing to the relay type switches. This switch can be manufactured by molding gin batch production and may have potential applications in extremely bright traffic control,, high intensity advertising display, and communication.

A system composed of two type fiber-optic displacement sensors is established to improve linearity in this paper by computation being made between a random type and a semicircle type reflective fiber-optic displacement sensor. On the basis of the measurement, the displacement sensor has a good linearity in a large range of more than 5mm. Meanwhile the light intensity distributions are measured in this paper.

A fiber optic pulsed magnetic-field sensor based on Faraday magneto-optic effect is described in this paper. Its dynamic range is better than 70 dB within the nonlinearity of 5 percent and its noise equivalent magnetic flux density is about 1.5 by 10^-6 T. By the method of frequency spectrum analyze, the frequency response characteristic of the sensor is measured and its -3dB bandwidth is about 200kHz. The experimental results indicate that the sensor can be used for pulsed magnetic field or current measurements.

A refractometric fiber-optic chemical sensor bas don mode- filtered light detection (MFLD) was designed. This sensor was fabricated by inserting a non-chem- or bio-modified fiber core into a silica capillary with a CCD detector as the multichannel-signal capture. An interesting observation was obtained that there is an increase in signal with a decrease in sample refractive index in this unclad fiber sensor, just contrary to the polymer-clad fiber instead sensor reported previously. Academic deduction of the light propagation in detail, which was demonstrated by our experimental results, further interprets the reason of the difference between the unclad sensor and the polymer-clad sensor, and provides theoretical foundation on development of a MFLD-derived analyzer with synchronization of separation and assay in future work. This sensor was also demonstrated to successfully apply to detection of acetic acid with linear response of 0-90 percent and relative coefficient of 0.9972. The sensor's advantages in high S/N ratio and instant response show its potentials in food and chemical industries as a general sensor.

In order to measure the transient electric field in high- voltage substations, the electric field sensor has to be developed. The active sensor has been developed. In this paper a novel passive sensor is presented. This design is based on the study of the transfer characteristic of the spherical transient electric field probe and the analysis of the traditional passive sensor. As for the spherical probe, the relation of measurement capacity and the induce voltage can be used to select the measurement range. For the passive sensor, the differences of the detection methods of sensing signal is analyzed. When it is directly used to measure the transient electric field in the high-voltage substation, the drawbacks are pointed out in this paper. Based on the former analysis, the advantages of the novel passive sensor are summarized.

Lead-zirconate-titanate (PZT) thin films on silicon were prepared by a sol-gel method. Phase characterization and crystal orientation of the films were investigated by x-ray diffraction analysis (XRD). It was shown that the PZT thin films had a perfect perovskite structure after annealed at a low temperature of 600 degrees C. PZT thin films were chemically etched using HCl/HF solution through typical semiconductor lithographic process, and the etching condition was optimized. The scanning electron microscopy results indicated that the PZT thin film etching problem was well solved for the applications of PZT thin film devices.

In this paper, nano technology, nano sensor, nano devices, bionics of nano technology are discussed. The significance of the topic includes its contribution to biology and medicine as well as to engineering and technology. Cell may be the best object to be researched. Cell membrane may be the key of such a study. By means of simulating the structure and function of a cell's membrane, a molecular network model of nanofactory are suggested. Methodologies for realizing such models are presented. Among them, nano fabrication biotechnology, chemical method and nano integration are illustrated. Nano fabrication in a broad sense will be preferable to others. At last, a diagram showing the perspectives of the new technologies including measuring and control of psychological state, establishing platform for monitoring a single cell, constructing nano robot and nanofactory etc. was depicted.

Self-assembly as a novel method to prepare ultrathin functional films has drawn more and more attention in recent years. The preparation methods, structure, characterization and NO₂ gas sensing properties of polyaniline (PAN) ultrathin films are studied in this paper. Firstly, PAN, bpolyphthalocyanine and polycation were prepared as raw materials for self-assembling PAN ultrathin films. The self- assembled PAN ultrathin flims with polymeric and phthalocyanines were prepared based on doping-induced deposition effect. These films were characterized by UV/visible spectroscopy. The study on self-assembling mechanism show that it is acids that drives the self- assembling process, which is dependent on the PAN solution property, the types of solvents and polymeric acids, the molecular weight of polymers and temperature. At last, the NO₂ gas sensing properties is studied in this paper.

This paper presents a novel method for the fabrication of micro electromagnetic relays based on MEMS technology. Fabrication process and the partial test results are given in detail. Th emian advantages of the micro relay include small volume, low weight, rapid response, and longevity. In addition, it takes the performance between the common electromagnetic relay and the solid-state one, thus the proposed micro relay may be promising in the future.

Carbon fiber which has excellent strength is a kind of resistant-magnetic material, but a kind of magnetic carbon fiber with Fe coating was successfully prepared by sol-gel process. The formation process of magnetic fiber was identified by XRD. The magnetic properties of the magnetic carbon fiber which is a kind of soft magnetic material with intrinsic coercivity to 12748.7A/m were evaluated by VSM. During magnetization. Special magnetic-resistance of magnetic fiber were found. Mechanical and magnetic properties of magnetic fiber were presented in this paper. Possibly the magnetic fiber could be used minisensor.

Anisotropic magnetoresistance (AMR) effect thin film sensor has a very wide prospect in application. In this paper, we studied the structure, the AMR and the size effect of the Permalloy film with (Ni_0.81Fe_0.19)_0.66Cr_0.34 layer as buffer layer. The resistance of NiFeCr is larger than that of Ta and has the same face-cubic structure as NiFe, which could depress the current shunting effectively and be benefit to the formation of the well-textured NiFe layer. The measurements of XRD and AFM showed that, the specimens with (Ni_0.81Fe_0.91)_0.66Cr_0.34 and Ta buffer have close surface roughness, while the former had more textured structure. (Delta) R/R decreased and the saturation field increased with the reduction of the width of the AMR stripes etched by ion beam. However, the magnetic field sensitivity could still reach 0.16 percent/Oe when the width reduce to 30micrometers , and could correctly respond to an alternative magnetic field.

Ferroelectric thin films of PbTiO₃ deposited on silicon substrates by sol-gel method. X-ray diffraction analysis shows that the PT thin films are well crystallized. Electrical and ferroelectric properties such as capacitance- voltage, polarization-field, dielectric-frequency, leakage current, and fatigue properties of the PT thin films are tested. Experimental result of the PT thin films shows that these thin films have quite good ferroelectric and electrical properties.

The film's sputtering fabrication has a lot of advantages than other technique. But it meets some difficulty in fabricating InSb film and the oxidation of In is one of them. Because the In among InSb is a kind of active element, and oxygen is in a ionogenic state in sputtering process, the In among InSb is easily oxidized. It will result in that InSb film loses its Hall effect. By analysis, we can find that the oxygen in vacuums mainly comes from the minimal oxygen among Ar gas. The spongy Ti absorbing in high temperature purifying technique was tested then. The temperature should be controlled at 900 degrees C. The purified effect won't be ideal if the temperature is low. The experimental result had been taken Auger electronic spectrum measure and the measured results are presented. The result indicate that the InSb film will not have O₂ if use the Ar gas that had been purified. The results is perfect.

The configurations of electrochemical silicon etch-stop are discussed in this paper. An electrochemical etching machine with software and hardware, which can control the etching process of silicon very well, is designed and fabricated bas don the theory of electrochemical etching. Accurate etching temperature is obtained by modified integral algorithm of PID presented in temperature control in software. With an algorithm presented in control of etch-stop, the tech-stop point can be detected according to the characteristics of p- n junction current-time in electrochemical etching. The machine with hardware including S/H, controller and actuator can adapt to all wet etching configurations such as poly- electrode electrochemical etch-stop.

This paper describes the mechanism of light addressable poteniometric sensors (LAPS) from the viewpoints of Semiconductor Physics, and introduces the fabrication of a multi-parameter LAPS chip. The MEMS technology is applied to produce a matrix of sensing regions on the wafer. By doing that, the cross talk among these regions is reduced, and the precision of the LAPS is increased. An IR-LED matrix is used as the light source, and the flow-injection method is used to input samples. The sensor system is compact and highly integrated. The measure and control system is composed of a personal computer, a lock-in amplifier, a potentiostat, a singlechip system, and an addressing circuit. Some experiments have been done with this device. The results show that this device is very promising for practical use.

Using the radio frequency magnetron sputtering approach to prepare CoFe/Cu/NiFe spin valve tri-layered films, we study the substrate temperature, CoFe insertion layer and NiFe insertion layer effect on the giant magnetoresistance. It is found that the magnetoresistance descends when the substrate temperature ascends. It is attributed that the interfacial spin-dependent scattering weakens because the diffusion at the interface strengthens at higher substrate temperature. The magnetoresistance increases when the spin valves are inserted by CoFe layers in Cu/NiFe interfaces and the magnetoresistance decreases when the spin valves are inserted by NiFe layer in CoFe/Cu interfaces. This implies that a smooth and continuous interface is more easily obtained in CoFe/Cu than in NiFe/Cu interface. Smooth interfaces strengthen the interfacial spin-dependent scattering that increase the giant magnetoresistance.

Silica coated magnetic nanoparticles have been prepared by sign water-in-oil micro emulsion technique, and have been characterized by Transmission Electron Microscopy and e-ray diffractometer. Concanavalin A was covalent immobilized on the surface of silica coated magnetic nanoparticles. Dextran-Rhodamine B could be easily separated from aqueous solutions by the functionalized nanoparticles. The result implied that the preparation route is easy to yield silica coated magnetic nanoparticles which can be modified for the separation of other target biomolecules, cells, and etc.

Considering that the resistance of macromolecule resistor varies in a wide range and humidity sensor component is sensitive to temperature as well, a intelligent high- precision macromolecule resistance temperature/humidity instrument was proposed in this paper, the instrument is based on the integration of frequency-and-period-measuring method, and sensing characteristic calculation and compensation using interpolation. Practical applications show that the instrument has the advantages of high precision, simple peripheral circuit, low cost, suitability for remote measurement, strong ability of anti-interference and wide operation range.

The DOAS system is one that combine optics, mechanics, electricity and computer technologies in it. The long optical path DOAS system which we developed is of great sensibility and lower measure limits. It can get the concentration of several kind of trace gases in a given space region simultaneously in the same waveband. This paper provides the method of determining the correspond wavelength in the signal sampling and the method to calculate the delay time.

The principle, the manufacture and its application of the taste image sensor based on LB films were introduced in this paper. The sensor were composed of lipid membranes with different characteristics and the membranes were deposited on the LAPS system by LB method. In the experimental study, the response potential of fiber kinds of basic taste substances were measured by taste image sensor in order to get different response potential images. Besides, the image processing and pattern recognition were also carried out to detect different taste substances.

Based on the neuron model and learning strategy, the neuron intelligent PID control system is set up in this paper. The neuron model-free PID control method is posed. The simulation tests with an example of a hydraulic turbine generator unit are made. The result show that god control performances are obtained. This new intelligent controller is very simple and has very strong adaptability and robustness. It can be used directly in practice.

A novel structure of front end passband bulk acoustic wave (BAW) filter using surface micromachining in is designed. The advantages and disadvantages of fabricating BAW RF filter using surface and bulk micromachining are discussed. The analytical solutions of the wave equation for the electrode-piezoelectrics-electrode sandwich structure on support film in the BAW RF resonators are presented.

Because of existing non linearities, time-varying parameters and uncertainties in turning processes, it is difficult to obtain satisfied performances for modeling base control methods. In this paper, the model-free PID control method with neuron tuning gain is prosed for a constant cutting force metal turning process. In order to reach the purposes of enhancing the control system stability and improving the dynamic performances, the model-free PID control method keeps the cutting force to be constant by using the neuron to change the controller gain on-line when a cutting tool cuts at various cutting depths or the spindle operates in different speeds. These simulation results of using the proposed controller for a cutting process show that very strong robustness, good disturbances resistant and satisfied performances are obtained. This control method is very simple and can be easily implemented in practical cutting processes.

In this paper the method of extracting weak periodical signals form being merged in the background of Gauss white noise by use of the cycling auto-correlation approach was presented, which is aimed to solve the difficulties encountered in the practical usage of auto-correlation function in this aspect. Some results of simulation by computer to this approach were given at the end of this paper showing the forthright and the better real-time characteristic of this method.

Wavelet transform is a new and good image processing method that well separates different frequency components of an image. This paper mainly discuses image edge detection with the band-pass filtering property of wavelet transformation. After wavelet transforming and edge extracting, an image can be clearly seen in detail. Compared with other image edge extraction methods, such as Roberts operator, Laplacian operator, Sobel operator and Kirsch operator, this method has good extraction effect and is suitable to binary process. This is very useful to medical diagnose and remote sense image recognition.

Transducers or sensors play a very important role in industry measurement and control system. One of the key specifications of sensor is its degree of accuracy. The low precise sensor, which acquires a higher degree of accuracy, can be enhanced its cost performance. In this paper, a new neural networks-based stress-sensor accuracy enhancement scheme is proposed. The neural networks can be considered as nonlinear filter, which reduces the noise of low accuracy sensor. The neural network model with six input nodes, five hidden nodes, and one out nodes is chosen in sensor data filter. We provided with both the noisy signal from low accuracy sensor and noiseless signal from signal from high precise sensor. The neural networks can be trained to reduce the nosie level of senor as s signal noise filter. The practice uses show that our method can provide sensor greater accuracy and environment suitability.

This thesis introduces the floating capacitance transducer for crude oi8l multi-phase flow and analyses the reconstruction algorithm. Analysis shows the structure of the floating array capacitance transducer can provide higher signal amplitude and more uniformity of sensitivity. The iterative schemes can reduce the distortion produced by the linear back projection image reconstruction algorithm.

The first task of signal processing and image processing is to get rid of noise. In this paper, an adaptive weighed vector median filter for color image is presented on the base of the performance analysis of several filters. This method has better characteristic of fast filtering and noise depressing performance. It is a better edge preservation filter that does not introduce new colors.

Crop working condition is related with many parameters, such as temperature, moisture, sunlight, so how to determine the goodness of the working condition is of something difficulty. A new method based on fuzzy pattern recognition is put forward to realize monitoring the working condition of the crop in the plant agriculture. Results how that the scheme is feasible and efficient.

It is needed to enhance sensitivity and resolving power in microresonators, which give weak frequency variation in perceiving pressure and temperature. The simulated extraction of weak frequency variation is carried out with the manifesting resonant frequency-locking property when system transits from chaotic to great periodic motion. With signal preprocessing used bandpass sampling and down sampling, measurement system is founded based on chaos. At the same time it is pointed out that the system can realize flexible measurement in silicon microresonators.

Radio frequency capacitance sensor is usually used in the intelligent inspection of the water-content in oil products. This method depends on the great difference between the water dielectric constant and oil. The dielectric constant of water is so much bigger than that of the oil that the radio frequency shoed by them is much different.

The computer- or microprocessor-based signal processing technology is one of the demodulation and processing methods capable of suppressing noise interference and enhancing signal-to-noise ratio. In this paper, the technology of software filtering and demodulation based on wavelet transform is presented. According to the features of band- pass and time-frequency domain localization of wavelet transform, a linear combine wavelet transform is used to approach an ideal narrow-band filter, and the designed filter has a fine filtering character. It provides a more convenient method for signal demodulation analysis and multi-pass-band components filtering in engineering signal processing. It has been used in the case of optical current transformer and can be developed to other signal processing applications.

Taste sensor as a new kind of chemical sensor has been studied by many researchers. We have developed several types of taste sensor system and some new recognition methods for taste substance. Kiyoshi Toko et al proposed a new kind of chaos taste sensor that is based on sensor chaos dynamics. In this paper, we improve the taste sensor based on chaos dynamics and proposed a new method for the pattern recognition of tastes. We use three kinds of tastes, i.e., sweetness, salty taste, and sourness. They cause the membrane oscillate in different form, and the complexity is not the same. We can detect taste based on the new method.

An application of multiline method in measuring the effective dielectric constant of micromachiend microwave transmission lines is presented in this paper. This multiline method does not need a network analyzer calibration. It produces the effective dielectric constant of the structure using propagation constant measurements. For comparison, we performed measurements in micromachined microwave transmission lines both before and after they were suspended. The measurement result show that at high frequency the real part of the effective dielectric constant of the structure is about 6 before suspending and is about 1 after suspending. The imaginary part of the measured effective dielectric constant of the structure is about zero because the transmissions line is very short.

This paper presents a new general framework for multisensor fusion based on a distributed detection. Parallel processing and distributed multisensor fusion, as rapidly emerging and promising technologies, provides powerful tools for solving this difficult problem, The distribution and parallelism of proposing and confirming of hypothesis in condition and diagnostic is prosed. A combination serial and parallel reconfiguration of n sensors for decision fusion is analyzed. It shows the result for a real-time parallel distributed complex machine condition monitor and fault diagnostic system.

Piezoelectric actuators often work in a close-loop feedback position control system due to hysteresis. Our objective is to make an actuator self-sense its output force and displacement without using extra sensor, which is termed self-sensing actuator/actuation (SSA). A compound circuit was proposed to voltage-drive the piezoelectric actuator and get the resulting charge concurrently. Based on the circuit, the unstressed actuator can self-sense its free strain. If the actuator is externally stressed, an observer was constructed to estimate the actuator's stress and strain state. The observer-based self-sensing approach is akin to state estimation techniques, depending on the fact that the electric field is controllable and the electric displacement is measurable. In order to compensate hysteresis, voltage versus charge relation was modeled sign GMS model, and the observer was improved to a nonlinear one. The observer-based SSA approach successfully bypasses the impedance mismatching problem bothering the bridge-based SSA approach. Experiments validated the approach.

In this paper, the micro-fluxgate model of single core is presented. Under different excitation or external magnetic field conditions, the characteristics of the model were analyzed and then the structural parameters of the core were optimized by FEM. The simulation results show that: (1) the linear measurement range is 5.2e-7 to approximately 2.6e-4T; (2) the sensitivity is linear with the excitation frequency; (3) for Typel micro-fluxgate, a maximal sensitivity can be reached at 200KHz with the core width near to 0.7mm.

A method based on a quartz crystal microbalance (QCM) was used for the first time to analyze oil quality on line. When the QCM is immersed in the oil, the resonant frequency will change according to the change of viscosity, density of oil on the crystal electrode. According to this principle, Quartz Crystal Microbalance (QCM) with temperature sensor is a novel test technique that allows for the on-line, real- time analysis of quality of the oil. In this article the principle and measuring device of QCM as oil analysis sensor are described. The key design of the hardware of this system is given.

The structure and principle of the remote supervisory and control network on heat-supply metering are presented here. This network system uses the public telephone system to implement the remote data exchange and transmission, so the net-structure is convenient and economic. The communication control mode and programming method are described in detail in the paper.

Microarray technology has revolutionized genetic analysis. However, limitations in genome analysis has lead to renewed interest in establishing 'omic' strategies. As we enter the post-genomic era, new microarray technologies are needed to address these new classes of 'omic' targets, such as proteins, as well as lipids and carbohydrates. We have developed a microarray platform that combines self- assembling monolayers with the biotin-streptavidin system to provide a robust, versatile immobilization scheme. A hydrophobic film is patterned on the surface creating an array of tension wells that eliminates evaporation effects thereby reducing the shear stress to which biomolecules are exposed to during immobilization. The streptavidin linker layer makes it possible to adapt and/or develop microarray based assays using virtually any class of biomolecules including: carbohydrates, peptides, antibodies, receptors, as well as them ore traditional DNA based arrays. Our microarray technology is designed to furnish seamless compatibility across the various 'omic' platforms by providing a common blueprint for fabricating and analyzing arrays. The prototype microarray uses a microscope slide footprint patterned with 2 by 96 flat wells. Data on the microarray platform will be presented.