This PDF file contains the front matter associated with SPIE Proceedings Volume 7646, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

Exploratory research is conducted at the US Army Aviation & Missile Research, Development, and Engineering Center (AMRDEC) in order to perform assessments of the degradation of solid propellant used in rocket motors. Efforts are made to discontinue and/or minimize destructive methods and utilize nondestructive techniques to assure the quality and reliability of the weaponry's propulsion system. Collaborative efforts were successfully made between AMRDEC and NASA-Ames for potential add-on configurations to a previously designed sensor that AMRDEC plan to use for preliminary detection of off-gassing. Evaluations were made in order to use the design as the introductory component for the determination of shelf-life degradation rate of rocket motors. Previous and subsequent sensor designs utilize functionalized single-walled carbon nano-tubes (SWCNTs) as the key sensing element. On-going research is conducted to consider key changes that can be implemented (for the existing sensor design) such that a complete wireless sensor system design can be realized. Results should be a cost-saving and timely approach to enhance the Army's ability to develop methodologies for measuring weaponry off-gassing and simultaneously detecting explosives. Expectations are for the resulting sensors to enhance the warfighters' ability to simultaneously detect a greater variety of analytes. Outlined in this paper are the preliminary results that have been accomplished for this research. The behavior of the SWCNT sensor at storage temperatures is outlined, along with the initial sensor response to propellant related analytes. Preparatory computer-based programming routines and computer controlled instrumentation scenarios have been developed in order to subsequently minimize subjective interpretation of test results and provide a means for obtaining data that is reasonable and repetitively quantitative. Typical laboratory evaluation methods are likewise presented, and program limitations/barriers are outlined.

This paper explores the technical and commercial feasibility of nanotechnology based, high-efficiency, photovoltaic-thermoelectric hybrid solar cells as an environmentally-friendly, renewable energy source for residential and commercial buildings. To convert as much as possible of the usable photovoltaic (58% of the Energy Density) and thermoelectric (42% of the Energy Density) solar spectrum into electricity, a hybrid multilayer system is presented which comprises of 1) carbon nanotube (CNT) embedded in conducting polymers such as P3HT (poly(3-hexylthiophene) or P3OT (poly3-octylthiophene), 2) 3D gold nanostructures exhibiting plasmonic resonances for energy conversion, 3) nanoantenna architecture to capture IR energy, 4) a composite of Bi2Te3, SiGe nanocrystals and Au nanoshells as thermoelectric energy conversion layer, 5) configuration of the above items engineered in the form of meta-material designs that by virtue of their 3D structures ensure that incident light is neither reflected nor transmitted, but is rather all absorbed, 6) a multilayer arrangement of the above layers in a fractal architecture to capture all the wavelengths from 200 to 3000 nm⁸ and the matching electronic interface for each layer. The roll-to-roll manufacturing method presented will enable economical large-scale production of solar panels. This potentially transformational technology has the ability to replace the Si solar cell technology by reducing costs from $0.18/KWh to $0.003/KWh while introducing a more environmentally-friendly manufacturing process.

Gold metal nanoparticles have applications in bio sensing technology, nano-tube formation, and cancer therapy. We report attempts to synthesize gold nanoparticles within the ferritin cavity (8 nm) or to use ferritin as a scaffold for coating gold on the outside surface (12 nm). The intrinsic iron oxide core of ferritin is a semi-conductor and light can excite electrons to a conduction band producing a powerful reductant when a sacrificial electron donor fills the electron hole. We present a method using ferritin to photo chemically reduce Au(III) to metallic gold nanoparticles. During initial studies we observed that the choice of buffers influenced the products that formed as evidenced by a red product formed in TRIS and a purple produce formed in MOPS. Gold nanoparticles formed in MOPS buffer in the absence of illumination have diameters of 15-30 nm whereas illumination in TRIS buffer produced 5-10 nm gold nanoparticles. Increases in temperature cause the gold nanoparticles to form more rapidly. Chemical reduction and photochemical reduction methods have very different reaction profiles with photochemical reduction possessing a lag phase prior to the formation of gold nanoparticles.

Relative phase transformation rates are compared with TiO₂ sol-gel thin film and TiO₂ nanorods. TiO₂ thin film was prepared with sol-gel process using titaanium isoproxide (TIP) as a precusor, ethanol as a solvent and HCl as a catalyst. The TiO₂ nanorods were synthesized with low temperature proccess (100 °C) using TIP, oleic acid, and aqueous trimethylamine. The prepared thin film and nanorods were annealed at 850 °C for 3 h. X-ray diffraction patterns reveal that the TiO₂ thin film and TiO₂ nanorods have amorphase phase and anatase phase, respectively before annealing process. Approximately 60 and 3 % of TiO₂ thin film and TiO₂ nanorods transformed from anatase phase to rutile phase after annealing at 850 °C for 3 h. Relatively small amount of TiO₂ nanorods transformed to rutile phase compared with TiO₂ thin film. This small amount of phase transformation may be due to the small diameter of the TiO₂ nanorods, which have thermodynamecally favorable anatase phase.

Wireless nano sensors networks are being increasingly applied in many real-world applications, such as structural health monitoring, medical applications, smart clothes, battlefield communications, and intelligent highway systems. A systems approach to such applications require end-to-end infrastructure that includes sensors and sensor networking, wireless communication, reliable backbone networking,, computing infrastructure and other supporting systems. In fact, it fairly clear that sensor systems, communications systems, and computing systems need to interwork together to form a system of systems. The design and implementation of such complex systems need to take into consideration their intended functionality, operational requirements, and expected lifetime. Systems engineering provides the design and implementation framework to successfully bring large complex systems into operation by integrating multiple engineering disciplines into a structured development process, starting with identification of the need, and defining the initial concept, to formulating the requirements to detailed design, development and then, implementation. This paper brings together aspects of research that is being conducted as part of the Arkansas ASSET initiative, which is a multi-campus project supported by NSF Section 2 provides a systems engineering life-cycle modeling approach. Section 3 develops modeling and analysis of nanowires for a biological application. Section 4 provides insights into the design of wireless interfaces to provide wireless capability to wearable sensors for medical applications. Section 5 discusses the application of multiple input multiple output (MIMO) to improve reliability in wireless Section 6 proposes a data-driven adaptive transmission mechanism to improve both data quality and energy efficiency. Section 7 provides insights into the development of protocols for reliable transport of data over a wavelength division multiplexed optical transport network. Section 8 summarizes our findings.

Multicomponent semiconductor oxides mainly composed of elements like indium, zinc, tin or gallium are very promising new class of materials for application in transparent electronics, multifunctional sensors and other electronic applications. The major characteristic of these materials is high mobility, and the electrical behavior is a consequence of a conduction band primarily derived from spherically symmetric heavy-metal cationns orbital with (n-1)d¹⁰ns⁰ (n ≥4) electronic configuration. The carrier transport becomes insensitive to the degree of disorder of the film, and makes this class of quasi-polycrystalline and amorphous semiconductors attractive for numerous applications.We report here on the environmental sensing, such as ultra-violet-radiation and various gases of pulsed-laser deposited composite semiconductor films. These films demonstrate outstanding sensing capability from measuring the surface resistivity taking into account the absorption of sensing species. Our results show new possibilities for the low-cost high performance environmental sensors for numerous potential applications. The details of the results will be presented.

Piezoelectricity is one major actuating mechanism of cellulose Electro-active paper (EAPap). In order to enhance piezoelectric performance of cellulose, thin piezoelectric sodium-potassium niobate, Na0.5K0.5NbO3(NKN), film on cellulose, silicon and glass substrates was deposited by magnetron sputtering method. As grown NKN layer on different substrates was characterized by XRD, AFM and electrical measurements. By increasing the RF power, crystal structures were observed from the NKN films on silicon and glass substrate, while no peak was observed from cellulose due to microcracks of films. The detail structural and electrical observation was discussed.

We have studied ferroelectric properties of Pb (Zr0.6Ti0.4) O3(PZT)/SrTiO3 thin films grown on platinized silicon substrates using pulsed-laser deposition and magnetron sputtering technique. The spontaneous polarization (Ps) and remnant polarization (Pr) varies between 15.5 K and 100 K from 33-38 μC/cm² and 25-30 μC/cm²,respectively. Similar values of Ps and Pr were also observed until temperature reached to 300K. However, more pronounced ferroelectric hysteresis loops were observed between T= 323 to 353 K. The Ps and Pr remain around 36-40 μC/cm²and 23-28 μC/cm², respectively, between T = 323 to 353 K. The remnant polarization remains fairly consistent over the chosen temperature range. X-ray diffraction and high-resolution microscopic studies reveal that the Pb (Zr0.6Ti0.4) O3 layers are superior in crystalline quality than that of SrTiO3. The PZT in multilayered films show remarkably enhanced polarization properties relative to their single layers on the same substrates. The collective contribution of dipole moments from each layer is the reason for such enhancement in polarization properties. This growth strategy may be very useful for fabrication of sensitive sensing and other relevant devices.

A carbon nanocomposite-based contact mode interdigitated center of pressure sensor (CMIPS) has been developed. The experimental study demonstrated that the CMIPS has the capability to measure the overall pressure as well as the center of pressure in one dimension, simultaneously. A theoretical model for the CMIPS is established here based on the equivalent circuit of the CMIPS configuration as well as the material properties of the sensor. The experimental results match well with the theoretical modeling predictions. This theoretical model will provide guidelines for future advanced sensor development based on the CMIPS. A system mapped with two or more pieces of the CMIPS can be used to obtain information from the pressure distribution in multi-dimensions. As an intelligent system component, the inexpensive CMIPS can be used broadly for improving sensing and control capabilities of aircraft and measurement capabilities of biomedical research as well as chemical industries.

Alternate fuel sources are becoming increasingly important as the reserve of fossil fuels decrease. We describe a photosynthesis mimic that is capable of extracting electrons from sacrificial electron donors. This model is based on the bio-photo-catalyst ferritin. Ferritin is an iron storage protein that naturally sequesters ferrihydrite inside a spherical 12 nm protein shell. Ferrihydrite is a semi-conductor that functions as a photo-catalyst in aqueous solvents. Ferritin has been shown to photoreduce Au³⁺ to form Au(0) nanoparticles. Citrate acts as a sacrificial electron donor to supply electrons for the photoreduction. We describe studies designed to understand the mechanism of this catalyst in order to improve the efficiency of the reaction. We have developed a spectrophotometric assay to simultaneously illuminate the sample and kinetically monitor the formation of products of Au³⁺ reduction. We report that buffers containing sulfur significantly increase the rate of the reactions. Control reactions with colloidal ferrihydrite nanoparticles do not catalyze the photochemical reaction, but produce a black precipitate indicating that the protein shell has an important function in nanoparticle formation.

This paper addresses the development of a wireless sensor system array for the detection and identification of bioterrorism agents and hazardous vapors and other gases with a realistic goal of "stick and forget sensing" especially attractive to homeland security needs. New and improved sensors are needed for many security applications with fast, reliable and sensitive detection and identification. Some of the most important tools in today's national security are biological and chemical agents' detection and identification. These devices need to be small and fast so that they can easily detect and identify any traces of hazardous materials. Biosensors are analytical devices which use biological interactions to provide either qualitative or quantitative results. Due to its ability to manipulate and organize matter and structures from atomic up to molecular scales, the nanotechnology is widely viewed as the most significant technological frontier which has to be explored in many areas including physical, chemical, electrical and biological sciences. Design and successful development of devices of the size of few nm to couple of hundreds of nm, nanotechnology has been heralded as most powerful technology as ever seen before. This has lead to the development of better materials, highly sensitive sensing systems and wide verity of nano-devices. This sensor array is based on Multi-walled Carbon Nanotube (MWCNT) as sensing element, which is synthesized and chemically bonded with different polymers for sensing different biological agents and gases. An array of these sensing elements with integrated ChemFET is connected to a low power wireless system for the real-time detection and identification. We have successfully demonstrated the detection and identification of various gases and chemicals using wireless setup.

The past decade has witnessed remarkable progress in Organic electronics and Organic sensor technology on flexible substrates. Temperature and strain sensors for wireless active health monitoring systems have been tested and demonstrated. These sensors need control circuits to condition and transmit the measurand to the data acquisition system. The control circuits have to be incorporated on to the same substrate as the sensing element. So far, Pentacene based Organic Thin-Film Transistors (OTFTs) have been the most promising candidates for integrated circuit applications. To this end, optimization of the OTFT fabrication process is needed to obtain reliable and reproducible transistor performance in terms of mobility, threshold voltage, drive currents, minimal supply voltage and minimal leakage currents. The objective here is to minimize the leakage losses and the voltage required to drive this circuitry while maintaining process compatibility. The choice of dielectric material has been proven to be a key factor influencing all the desirable characteristics stated above. This paper investigates the feasibility of using a High K/Low K, Tantalum Pentoxide/Poly (4-vinyl phenol) (PVP) hybrid dielectric in Pentacene-based OTFTs to lower the operating voltages. Inverters and simple logic gates like 2-input NAND are simulated with these OTFTs. The results indicate that these OTFTs can indeed be used to build large scale integrated circuits with reproducibility.

Electrically conducting rubber composites (CRC) with carbon nanotubes (CNTs) filler have received much attention as potential materials for sensors. In this work, Ethylene propylene diene M-class rubber (EPDM)/CNT composites as a novel nano sensory material were prepared to develop flexible strain sensors that can measure large deformation of flexible structures. The EPDM/CNT composites were prepared by using a Brabender mixer with multi-walled CNTs and organo-clay. A strain sensor made of EPDM/CNT composite was attached to the surface of a flexible beam and change of resistance of the strain sensor was measured with respect to the beam deflection. Resistance of the sensor was change quite linearly under the bending and compressive large beam deflection. Upon external forces, CRC deformation takes place with the micro scale change of inter-electrical condition in rubber matrix due to the change of contact resistance, and CRC reveals macro scale piezoresistivity. It is anticipated that the CNT/EPDM fibrous strain sensor can be eligible to develop a biomimetic artificial neuron that can continuously sense deformation, pressure and shear force.

Due to the many random factors from thermal fluctuations to wave interference, computational perfection in nanoICs is difficult to achieve. Defects and faults arise from instability and noise proness of nanoICs, which lead to unreliable results. A probabilistic computational model is needed to reduce such errors and to achieve more reliable computation. The probabilities of the outputs of this model can be calculated by the arithmetic expressions of the Boolean functions. This paper presents a method for transforming a low noisy reliability nanocircuit into a high reliability nanocircuit without using any hardware redundancy techniques. A class of nanocircuits, called reliability enhancement nanocircuits (RENC) is introduced. Each RENC is a simple logic circuit with a single input and output. It is shown that with a proper setting of the "logic threshold value" of the RENC, which determines logic value 0 or 1 for the input and output, the output (reliability) of RENC can be higher than its input reliability. Thus, when a RENC is connected to an output of a nanocircuit, the reliability of the entire circuit can be enhanced. A reliability enhancement nanowire (RENW) can be formed by cascading n number RENCs. It is also shown that by connecting each output of a low reliability nanocircuit with a RENW with sufficient number of RENCs , the reliability of the nanocircuit can be raised to any desirable higher level. This method is illustrated by examples and is applicable to any digital nanocircuit design using any nanotechnology.

A programmable second order oversampling sigma-delta analog-to-digital converter (ADC) is designed and fabricated in 0.5 μm n-well CMOS process for low-power interface electronics of a sensor node in wireless sensor networks. The sigma-delta ADC can be programmed to operate at three different oversampling ratios of 16, 32, and 64 to give three different resolutions of 9, 12 and 14 bits, respectively which impact the power consumption of the sensor module. The major part of power is consumed in the decimator of the ADC by the integrators which operate at the highest sampling rate. Hence, an alternate design is introduced in the integrator stages by inserting sign extension coder circuits and reusing the same integrators for different resolutions and oversampling ratios. The programmable ADC can be interfaced with on or off-chip nanosensors for detection of traces of toxic gases and chemicals.

Due to many random factors from thermal fluctuation to wave interference, physical perfection in nanoICs is hard to achieve. Defects and faults arise from instability and noise-proneness on nanometer scales. This leads to unreliable and undesirable results of computation. In order to ensure more computation, techniques are necessary to cope with such errors. This can be achieved in nanotechnology using probabilistic models. In these models, it is assumed that the input and output signals are performed with probability because of noise signals, and the implemented logic function is performed within some probability because of the nature of nanoICs. In this paper, methods for computing the output probability of sequential logic nanocircuits are presented to extract information from sequential nanoICs in nanospace of a noisy environment, it is found that the most appropriate measure of information is the measure of entropy. The results of the study of probabilistic behavior and information measure of sequential nanoICs are reported with illustrative examples.

Very few papers have been written on the topic of a quantum version of the finite state machine, (or finite state automata). Furthermore, these papers only serve to define what a quantum finite state machine might be in the mathematical sense using the early languages of Turing machines. This paper seeks to further develop the notion of a quantum finite state machine (FSM) using constructs developed for the classical FSM and utilized for classical FSM design. In particular the quantum state transition diagram (QSTD) is constructed to further the understanding and realization of quantum finite state machines and quantum computers.

A power beaming system to a Micro Aerial Vehicle (MAV) using 5.8GHz microwaves has been developed. The system consists of three sub-systems; a pointing system, a tracking system, and a receiving system. The MAV is tracked using the phase information of pilot signal. Software retro-directive function has been realized through a PC control and a microwave beam is pointed to the MAV using an active phased array. The beam divergence was about 9deg and the beam steering angle was from -9deg to +9deg. Light-weight flexible rectenna array made of cupper tapes and a thin polyimide film was mounted on a wing of the MAV model, and the electric motor was driven by the received power. The weight per unit reception area was 26mg/cm².

For many sensors, bio-sensors, and probes, it is critical to provide a suitable power source nano or micro scale feature size, flexible structure, and physiologically friendly materials. In this study, rectenna array was considered as a power source using microwave that transmits through the tissues of humans or animals. In addition, biological effects on humans and animals are discussed as well.

In this work, reliability of communications systems in wireless sensor networks is addressed through the switchable phase-locked loops. The switchable phased-locked loop frequency synthesizer can work experimentally in a wide frequency range from 250 MHz to 700 MHz and is designed in 0.5μm n-well CMOS process. CMOS is the commonly used technology for communication systems wherein hot carrier injection and negative bias temperature instability are prime contributors to reliability. It is shown that both the hot carrier injection and negative bias temperature instability affect the performance of the phased-locked loop. The RMS jitter of the PLL increases by 40 ps and 23 ps for 4 hours of hot carrier injection and negative bias temperature instability stress, respectively. The experimental results show that the RMS jitter of the phase-locked loop varies from 30 ps to 123 ps as output frequency changes. The phase noise of phaselocked loop is -61 dBc/Hz at 10 kHz offset frequency and -104 dBc/Hz at 1 MHz offset frequency under 700 MHz phaselocked loop carrier frequency.

In this research we developed wireless sensor system for security application. We have used geophone to detect seismic signals which are generated by footsteps. Geophones are resonant devices. Therefore, vibration on the land can generate seismic waveforms which could be very similar to the signature by footstep. The signals from human footstep have weak signals to noise ratio and the signal strength is subject to the distance between the sensor and human. In order to detect weak signals from footstep, we designed and fabricated 2-stage amplification circuit which consists of active and RC filters and amplifiers. The bandwidth of filter is 0.7Hz-150Hz and the gain of amplifier is set to 1000. The wireless sensor system also developed to monitor the sensing signals at the remote place. The wireless sensor system consists of 3 units; a wireless sensor unit, a wireless receiver unit, and a monitoring unit. The wireless sensor unit transmits amplified signals from geophone with Zigbee, and the wireless receiver unit which has both Zigbee and Wi-Fi module receives signals from the sensor unit and transmits signals to the monitoring system with Zigbee and Wi-Fi, respectively. By using both Zigbee and Wi-Fi, the wireless sensor system can achieve the low power consumption and wide range coverage.

Zigbee Sensor Network system has been investigating for monitoring and analyzing the data measured from a lot of sensors because the Zigbee Sensor Network has several advantages of low power consumption, compact size, and multi-node connection. However, it has a disadvantage not to be able to monitor the data measured from sensors at the remote area such as other room that is located at other city. This paper describes the software structure to compensate the defect with combining the Zigbee Sensor Network and wireless LAN technology for remote monitoring of measured sensor data. The software structure has both benefits of Zigbee Sensor Network and the advantage of wireless LAN. The software structure has three main software structures. The first software structure consists of the function in order to acquire the data from sensors and the second software structure is to gather the sensor data through wireless Zigbee and to send the data to Monitoring system by using wireless LAN. The second part consists of Linux packages software based on 2440 CPU (Samsung corp.), which has ARM9 core. The Linux packages include bootloader, device drivers, kernel, and applications, and the applications are TCP/IP server program, the program interfacing with Zigbee RF module, and wireless LAN program. The last part of software structure is to receive the sensor data through TCP/IP client program from Wireless Gate Unit and to display graphically measured data by using MATLAB program; the sensor data is measured on 100Hz sampling rate and the measured data has 10bit data resolution. The wireless data transmission rate per each channel is 1.6kbps.

A cellulose solution was prepared by dissolving cotton pulp in LiCl/ N,N-Dimethylacetamide (DMAc) solution, and functionalized multi-walled carbon nanotubes (MWCNTs) were reacted with N, N-Carbonyldiimidazoles to obtain MWCNTs-imidazolides. By acylation of cellulose with MWCNTs-imidazolides, MWCNTs were covalently bonded with cellulose chains. Using the product, MWCNTs covalently bonded cellulose composite (M/C) composite was fabricated with mechanical stretching to align MWCNTs with cellulose. Finally, inter-digital comb electrode was formed on the composite via lift-off process. Chemo-electrical properties of the M/C composite in response of absorption of the volatile vapors corresponding to 1-propanol, 1-butanol, methanol and ethanol were investigated. Due to sensitive and reversible expansion/contraction of the M/C composite matrix in response to absorption of each analyte, the M/C composite showed fast and reversible change in chemo-electrical property. The ranking of relative resistance response of the composite was methanol < ethanol < 1-propanol < 1-butanol.

Organic (electronic) Light Emitting Diodes (OLEDs) have been shown to have applications in the field of lighting and flexible display. These devices can also be incorporated in sensors as light source for imaging/fluorescence sensing for miniaturized systems for biomedical applications and low-cost displays for sensor output. The current device capability aligns well with the aforementioned applications as low power diffuse lighting and momentary/push button dynamic display. A top emission OLED design has been proposed that can be incorporated with the sensor and peripheral electrical circuitry, also based on organic electronics. Feasibility analysis is carried out for an integrated optical imaging/sensor system, based on luminosity and spectrum band width. A similar study is also carried out for sensor output display system that functions as a pseudo active OLED matrix. A power model is presented for device power requirements and constraints. The feasibility analysis is also supplemented with the discussion about implementation of ink-jet printing and stamping techniques for possibility of roll to roll manufacturing.

Cellulose has received much attention as an emerging smart material, named as electro-active paper (EAPap), which can produce a large bending displacement with applied external electrical field. In spite of many advantages over other reported electro active polymers, the material improvement as an actuator is required due to the poor performance under ambient humidity condition. This paper reports the successful development of highly durable EAPap actuator working at an ambient condition with large displacement output. Nanoscaled polypyrrole was introduced into cellulose EAPap by in-situ polymerization technique followed by activation in ionic liquid solution, which results in cellulose-PPy-IL (CPIL) nanocomposite. CPIL based EAPap actuator showed nearly 100% improvement of the actuator performance compared with the pure cellulose based EAPap actuator systems.

A light driven microvalve activated by a thin organic photoelectric film that controls the expansion and shrinkage of a pH sensitive HEMA-AA hydrogel actuator is described in this paper. The self-assembled monolayer of oriented bacteriorhodopsin (bR) purple membrane patches are immobilized on a porous bio-functionalized gold (Au) surface using a biotin molecular recognition technique. When exposed to visible light, each bR molecule in the monolayer acts as a simple proton pump which transports hydrogen ions from the cytoplasmic to the extracellular side through a transmembrane ion channel that connects both sides of the membrane. The flow of ions from the photon activated bR changes the pH value of the ionic solution that surrounds the gel microactuator. The chargeable polymeric network undergoes a measureable geometric change when the pH of the ionic solution is shifted to the phase transition point pKa. The fabrication of the thin bR film and photo-responsive hybrid hydrogel are discussed. Preliminary experiments show that the 13nm self-assembled photoelectric layer can generate approximately 1.3mV/(mW·cm2) when exposed to an 18mW, 568nm light source. The photo-voltage produced by the monolayer is believed to be sufficient to change the pH of the surrounding ionic solution from its neutral state and trigger the swelling of the gel. Several design issues that need to be resolved before a fully functional light-driven microvalve can be created are identified and discussed.

A versatile optical characterization system is fabricated to measure various optical properties of materials and devices. The optical system is based on Michelson interferometer with advanced software algorithm to measure the intensity, phase angle, polarization state, and coherence of transmitted or reflected light from the materials and devices under test. Innovative contour map of phase/intensity vs. time/physical-quantity relation shows the dynamic evolution of interference patterns of multiple points in the analysis area. Advanced software semi-automatically calculates change of photon intensity, phase angle, polarization, and coherence which are results of various applied physical quantities such as voltage, electric field, current, temperature, pressure, chemical density, and reaction time. The measured optical property changes are converted by software to the changes of intrinsic and extrinsic properties of materials and devices under test. The system is designed for multi-point measurements which are suitable for 2D-array-pixel type devices. Therefore, this versatile optical measurement system can accelerate the development of advanced adaptive optics elements and phase control elements.

Bioelectronic photosensor arrays are hybrid devices where light-sensitive biological molecules are interfaced with microelectronic circuitry. In this paper, a mechanically bendable multi-pixel photosensor array that exploits the light transduction properties of thin bacteriorhodopsin (bR) films is described. The photo sensitive protein is immobilized on a flexible plastic substrate coated with a patterned indium-tin-oxide (ITO) microelectrode array. The thin bR film responds to light intensities over a wide spectral range with a peak response at 568nm. The photovoltage generated by the thin bR film remains approximately linear for a variety of wavelengths and over the light power range of 200μW to 12mW. By fabricating patterned photo sensor arrays on bendable plastic substrates it is possible to develop a variety of specialized non-planar imaging technologies. The design and development of a prototype cylindrical bR sensor array for a panoramic camera that detects movement in a wide 180° field-of-view is briefly described. Several key design challenges are identified and discussed.

Reliability is one important issue in using PEDOT: PSS as a strain gauge for large strain measurements. In our research, PEDOT: PSS strain gauge is fabricated on the polyurethane and porous substrate, which enhances the mechanical property when large strain and cyclic loads are applied to it. Our result shows that with the polyurethane as the substrate adhesion layer, the strain of PEDOT: PSS can go up to 17.7% and stabilize without reference resistance drifting.

The intra-cranial space, which houses the brain, contains cerebrospinal fluid (CSF) that acts as a fluid suspension medium for the brain. The CSF is always in circulation, is secreted in the cranium and is drained out through ducts called epidural veins. The venous drainage system has inherent resistance to the flow. Pressure is developed inside the cranium, which is similar to a rigid compartment. Normally a pressure of 5-15 mm Hg, in excess of atmospheric pressure, is observed at different locations inside the cranium. Increase in Intra-Cranial Pressure (ICP) can be caused by change in CSF volume caused by cerebral tumors, meningitis, by edema of a head injury or diseases related to cerebral atrophy. Hence, efficient ways of monitoring ICP need to be developed. A sensor system and monitoring scheme has been discussed here. The system architecture consists of a membrane less piezoelectric pressure sensitive element, organic thin film transistor (OTFT) based signal transduction, and signal telemetry. The components were fabricated on flexible substrate and have been assembled using flip-chip packaging technology. Material science and fabrication processes, subjective to the device performance, have been discussed. Capability of the device in detecting pressure variation, within the ICP pressure range, is investigated and applicability of measurement scheme to medical conditions has been argued for. Also, applications of such a sensor-OTFT assembly for logic sensor switching and patient specific-secure monitoring system have been discussed.

Accurate measurement of the turbulent flow is an important step toward understanding the mechanisms of many unknown phenomena. Turbulence generally can not be easily measured without significantly disturbing the original flow conditions. This paper introduces the efforts that aim to develop a bio-inspired sensor for monitoring turbulent flow. The sensor will consist of an array of micro-pillars or nano-pillars. Piezoelectric elements serve as transductors, which provides a key sensing element in the construction of micro-pillar. A prototype design was fabricated for the micropillar. The performance of sensing principle by this micropillar was evaluated and was found to be sensitive. The micropillar will be further refined into sensing arrays for real time sensing of flow turbulence.

Graphene nanoribbons (GNRs) are novel interesting nanostructures for the electronics industry, whereas their state as metallic or semiconductor material depends on the chirality of the graphene. We model the natural frequencies and the wave propagation characteristics of GNRs using an equivalent atomistic-continuum FE model previously developed by some of the Authors, where the C-C bonds thickness and average equilibrium lengths during the dynamic loading are identified through the minimisation of the system Hamiltonian. A molecular mechanics model based on the UFF potential is used to benchmark the hybrid FE models developed. The wave dispersion characteristics of the GNRs are simulated using a Floquet-based wave technique used to predict the pass-stop bands of periodic structures. We demonstrate that the thickness and equilibrium lengths for the different dynamic cases are different from the classical constant values used in open literature (0.34 nm for thickness and 0.142 nm for equilibrium length), in particular when considering out-of-plane flexural deformations. These parameters have to be taken into account when nanoribbons are designed as nano-oscillators.

Surface morphologies of the ZnO thin films with various thicknesses have been investigated. ZnO sol was prepared with zinc acetate dihydrate, 2-methoxyethanol, and monoethanolamine. Thicknesses of the ZnO films were controlled by a multiple coating process. The ZnO thin films were annealed at 750 °C. The film thickness increased as the coating time increased. From the XRD study, it is observed that the ZnO films exhibit wurtzite structure (002) and the diffraction intensity increased as the thickness increased. Effect of thickness on Schottky behavior was evaluated by measuring current-voltage characteristics. The pristine ZnO thin films with thickness of 132 nm exhibited Schottky diode characteristics with high rectification ratio.

Mass production of components with micro and nano scale surface features is known as micromoulding and is very sensitive to a number of variables that can cause important changes in the surface geometry of the components. The surface itself is regarded as a key element in determining the product's functionality and as such must be subject to thorough quality control procedures. To that end, a number of surface measurement techniques have been employed namely, White Light Interferometry (WLI) and Atomic Force Microscopy (AMF), whose resulting data is given in the form of large and rather unmanageable Cartesian point clouds. This work uses Partial Differential Equations (PDEs) as means for characterizing efficiently the surfaces associated with these data sets. This is carried out by solving the Biharmonic equation subject to a set of boundary conditions describing outer surface contours extracted from the raw measurement data. Design parameters are expressed as a function of the coefficients associated with the analytic solution of the Biharmonic equation and are then compared against the design parameters describing an ideal surface profile. Thus, the technique proposed here offers means for quality assessment using compressed data sets.

Drug delivery polymers play a role in late in-stent thrombosis of first generation drug-eluting coronary stents (DES) via an inflammatory reaction, which contributes to delayed endothelialization seen in patients with late stent thrombosis. Subsequent generation DES have non-polymer based DES whose surface pores serves as a drug reservoir. While drug elution for pores in the nanometer range have been shown to be comparable to polymer-based DES in terms of luminal renarrowing (i.e restenosis), how different pore sizes effect drug elution has not been fully characterized. We hypothesized that drug elution can be characterized with a mathematical model that takes into account the pore size of the stents and molecular characteristics of the eluted drug. Structural data from porous, non-polymer based stents were examined with pore radius ranging from the nanoporous to macroporous range (5 nm to > 10 mm). All stents eluted tacrolimus, sirolimus or paclitaxel. A mathematical model based on Stefan-Maxwell equations describing the mass transport of molecules through a porous media was constructed. A dimensionless number was derived characterizing molecular flux of the drugs through a porous membrane. It was observed that there was exponential rise in molecular flux of the eluted drug with pore sizes greater than 5 micrometers. The molecular characteristics of the eluted drug did not affect the molecular flux. In conclusions, stents in the nano- and microporous range will have similar drug elution profiles while macroporous stents will vary greatly. Careful attention to pore size may significantly enhance the design and efficacy of porous polymer free stents.

The development of micro and nano tech devices based on semiconductor manufacturing processes comprises the structural design as well as the definition of the manufacturing process flow. The approach is characterized by application specific fabrication flows, i.e. fabrication processes (built up by a large variety of process steps and materials) depending on the later product. Technology constraints have a great impact on the device design and vice-versa. In this paper we introduce a comprehensive methodology and based on that an environment for customer-oriented product engineering of MEMS products. The development is currently carried out in an international multi-site research project.

Peak and average energy usage in domestic and industrial environments is growing rapidly and absence of detailed energy consumption metrics is making systematic reduction of energy usage very difficult. Smart energy management system aims at providing a cost-effective solution for managing soaring energy consumption and its impact on green house gas emissions and climate change. The solution is based on seamless integration of existing wired and wireless communication technologies combined with smart context-aware software which offers a complete solution for automation of energy measurement and device control. The persuasive software presents users with easy-to-assimilate visual cues identifying problem areas and time periods and encourages a behavioural change to conserve energy. The system allows analysis of real-time/statistical consumption data with the ability to drill down into detailed analysis of power consumption, CO2 emissions and cost. The system generates intelligent projections and suggests potential methods (e.g. reducing standby, tuning heating/cooling temperature, etc.) of reducing energy consumption. The user interface is accessible using web enabled devices such as PDAs, PCs, etc. or using SMS, email, and instant messaging. Successful real-world trial of the system has demonstrated the potential to save 20 to 30% energy consumption on an average. Low cost of deployment and the ability to easily manage consumption from various web enabled devices offers gives this system a high penetration and impact capability offering a sustainable solution to act on climate change today.

This paper presents the design and optimisation of three types of high Quality (Q) factor air suspended inductors (symmetric (a), symmetric (b) and circular), using micro-electro-mechanical systems (MEMS) technology, for 10GHz to 20GHz frequency band. The geometrical parameters of inductor topology, such as outer diameter, the width of metal traces, the thickness of the metal and the air gap, are used as design variables and their effects on the Q-factor and inductance are thoroughly analysed. The inductor has been designed on high resistivity Silicon-on-Sapphire (SOS) substrate in order to reduce the substrate loss and improve the Q factor. Results indicate that the proposed inductor topology (symmetric (a)) has highest Q-factor with peak Q-factor of 192 at 12GHz for a 1.13nH inductance.

Single-phase hexangonal wurtzite GaN nanoparticles and GaN thin film were prepared by the sol-gel techniqiue.using Ga(NO₃)₃. For GaN thin films, Ga(NO₃)₃ was hydrolyzed with ethanol and acetic acid and aged for one day. GaO(OH) thin layer was fabricated with spin-coating and heating at 200 °C. For GaN nanoparticles, the Ga(NO₃)₃ was dissolved in concentrated nitric acid and adjusted pH to 8.5 using NH4(OH). Citric acid was added to the Ga(NO₃)₃ solution and heated 80 °C for 2 h. The solution was heated at 400 °C for 4 h to obtain the Ga₂O₃ nanoparticles. The GaO(OH) and Ga2O3 were annealed in a tube furnace at 900 °C for 1 h with NH₃ gas flow. The thickness of GaN thin film was approximately 46 nm. The grain size of the GaN thin film after converting from GaO(OH) to GaN, which was obtained by atomic force microscope image, was approximately 25-35 nm. The diameter of the GaN nanoparticles is approximately 15 nm with lattice fringes of 2.7 Α. The crystall has hexagonal wurzite structure, which is conformed by X-ray diffraction (XRD) pattern.

Thermochromic semiconductive polymers that change color in response to external stimuli, such as heat and radiation, can be utilized to monitor the temperature range and elapsed time profiles of stored and prepositioned munitions. These polymers are being tailored to create paints and coatings that will alert Army logistic staff of dangerous temperature exposures. Irreversible indication via color change in multiple thermal bands, 145 F - 164 F (63o-73°C), 165 F - 184 F (74° - 84° C) and over 185 F (>85°C) are possible with these thermochromic polymers. The resulting active coating can be visually inspected to determine if safe temperatures were exceeded. More detailed information, including cumulative time of exposure in certain temperature bands through changes in optical chromaticity describing the vividness or dullness of a color, can be assessed using a hand-held optical densitometer.

We present fabrication of a novel (Nd_0.7Ce_0.3)_10.5Fe_83.9 B_5.6magnetic powder and SU-8, UV patterened micromagnets. The magnetic powder with an averge particle size of 5μm-6μm has been prepared from an alloy ingot of raw materials which are put in a vacuum induction furnace, melt spun to obtain ribbons with nanocrystalline microstructure, further the ribbons are crushed using vibrating ball milling under intert atmosphere to obtain coarse powder (average particle size of 200μm). In order to obtain 5μm fine powder the course powder is jet milled at 6000rpm under inert atmosphere. The fine (Nd_0.7Ce_0.3)_10.5Fe_83.9 magnetic powder (refered to as MQFP-15) was ultrasonically uniformy dispersed in SU8 3010 using a horn tip probe operating at a frequency of 24 kHz. Micromagnets (length of 5mm, width 200 μm, height 30μm) are fabricated from the prepared composite via UV lithography and were tested usigng a SQUID magnetometer showed a remanent magnetization (M_r) of 62.80 emu/g and Coercivity (H_c) of 5290 G at 72 weight percentage of magnetic powder in PDMS matrix.

Exploratory research works have demonstrated the capability of conducting nanowire arrays in enhancing the sensitivity and selectivity of bio-electrodes in sensing applications. With the help of different surface manipulation techniques, a wide range of biomolecules have been successfully immobilized on these nanowires. Flexible organic electronics, thin film transistor (TFT) fabricated on flexible substrate, was a breakthrough that enabled development of logic circuits on flexible substrate. In many health monitoring scenarios, a series of biomarkers, physical properties and vital signals need to be observed. Since the nano-bio-electrodes are capable of measuring all or most of them, it has been aptly suggested that a series of electrode (array) on single substrate shall be an excellent point of care tool. This requires an efficient control system for signal acquisition and telemetry. An array of flexible TFTs has been designed that acts as active matrix for controlled switching of or scanning by the sensor array. This array is a scale up of the flexible organic TFT that has been fabricated and rigorously tested in previous studies. The integration of nanowire electrodes to the organic electronics was approached by growing nanowires on the same substrate as TFTs and fl ip chip packaging, where the nanowires and TFTs are made on separate substrates. As a proof of concept, its application has been explored in various multi-focal biomedical sensing applications, such as neural probes for monitoring neurite growth, dopamine, and neuron activity; myocardial ischemia for spatial monitoring of myocardium.

In the article, the design and stimulation is presented of an integrated circuit for the amplification and modulation of an electrical signal proceeding from a Micro-Electro-Mechanical Systems (MEMS) arterial pressure sensor. The signal consists of voltage ranking from 0-10 mV, 1 mA and frequency of 50- 500 Hz. This simple but effective design consists of an operational amplifier (op-amp) configured as a differential amplifier, which amplifies the signal (up to 1V and 10 mA), originating from a Wheatstone bridge in the MEMS sensor, and then this signal is modulated by Pulse width modulation (PWM). The technology employed in this circuit is MOSIS AMIS 1.5 um. The circuit was designed with a two-state op-amp, which is utilized in diverse stages of the system. The use of a differential amplifier, the op-amp, and PWM simplifies the design and renders this compact due to the employment of few components (40 transistors). The use of the PWM facilitates the signaling process at later stages. Results comprise the design of the circuit and the simulation. This consists of a schematic diagram of the layers of all the rules specified in the MOSIS AMIS 1.5 um. Electric and LTSpice software was employed for the design and simulation of the circuit. We present a complete description of the design philosophy, design criteria, figures, and final results.

We report on the growth and characterization of ZnO nanorods using chemical vapor deposition (CVP) with and without graphite, wet chemical reaction and gold attached ZnO nanorods called nanocomposites. Various novel arrangements of growth of uniform one dimensional ZnO nanostructures were observed. The ZnO nanostructures and the composite materials were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), The results of characterization demonstrated that ZnO nanostructures are one dimensional, the nanocomposites consist of both gold nanoparticles and ZnO nanorods. The result also shows that the gold nanoparticles were tightly attached on the nanorod surface. Our results suggest that ZnO nanostructures and nanocomposites are useful for solar cell, sensor applications. The detail of the results will be presented.

I have study in this paper to present a simple theoretical analysis of the thermo electric power under strong magnetic quantization (TPM) in superlattices with graded interfaces and compare the same with that of the constituent materials by formulating the respective dispersion laws. It has been observed, taking GaAs/Ga1-xAlxAs, CdS/CdTe, PbTe/PbSnTe, InAs/GaSb and HgTe/CdTe with graded interfaces as examples, that the TPM exhibits oscillatory dependence with the inverse quantizing magnetic field due to the SdH and allied superlattices effects and increases with increasing inverse electron concentration in an oscillatory manner in all the cases. The nature of oscillation is totally band structure dependent and the width of the finite interface enhances the numerical values of the TPM for all the aforementioned superlattices. The numerical values of the TPM in graded superlattices are greater than that of the constituent materials. In addition, the well-known expressions for the bulk specimens of wide-gap materials have also been obtained as special cases of our generalized analysis under certain limiting conditions.

In this paper, the dynamic behavior of a fixed-fixed double-walled carbon nanotube (DWCNT) conveying fluid is studied based on Euler-Bernoulli beam theory. The viscosity of the fluid and the nonlocal effect are incorporated in the formulation, and the Galerkin discretization method is used to solve the coupled equations of motions. The critical flow velocity of the fluid is obtained. Numerical simulations show that the van der Waals (vdW) interactions and the internal moving fluid play significant roles in the natural frequencies and the instability of DWCNTs. Also, the influences of the viscosity, nonlocal effect, aspect ratio and the surrounding elastic medium on the dynamic behavior of the double-walled carbon nanotube is studied in detail. It is found that a higher viscous-fluid-conveying DWCNT embedded in a stiff matrix with a larger aspect ratio make the induced instability vibration occur until a higher flow velocity.

A modified strain gradient plasticity theory is proposed based on the mechanism-based strain gradient (MSG) plasticity. This study is motivated by nonhomogeneity of polycrystalline materials. We believe that the geometrically necessary dislocations (GND) are generated on slip system as well as grain boundary to accommodate the deformation shape with internal stress. The new theory differs from the MSG plasticity in consideration of the GND on grain boundary and free surface effect of polycrystalline materials. A model describing the size effect on the tensile strength of crystalline metallic materials is investigated. Using the nonhomogeneity of polycrystalline materials and free surface effect, the density of the geometrically necessary dislocations during tension is derived. Using the proposed model, an analysis of the effect of both specimen size and grain size on the tensile strength of the polycrystalline materials is carried out.

In this study, the thermal properties of silicon samples with surfaces of porous and geometrical formation were reported. The etching methods of anodization chemical and heated KOH were utilized to perform the studied nano porous silicon (NPS) and pyramidal, respectively. Compared with usual surface formation of ordinary silicon sample, the larger surface to volume ratios were obtained from the fabricated NPS and pyramidal silicon devices. For the thermal applications such as thermal sensor and microheater, the etching profiles and surface to volume ration of studied were clarified by SEM measurement. Furthermore, the differential scanning calorimetry (DSC) was used to evaluate the thermal dissipation properties of studied samples.