This PDF file contains the front matter associated with SPIE Proceedings Volume 7207, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

There is a need for fast, reliable and sensitive biosensor arrays. We have used nanostructured plasmonic gold surfaces for the detection of biological species by surface enhanced resonance Raman scattering (SERRS). Careful, directed placement by Dip-Pen Nanolithography (DPN) of the biological species or capture chemistry, within the array facilitates efficient read out via fast Raman line mapping. In addition, we can apply parallel deposition methods to enhance the throughput of these combined techniques. SERRS is an extremely sensitive spectroscopic technique that offers several advantages over conventional fluorescence detection. For example, the high sensitivity of the method allows detection of DNA capture from single plasmonic array "pixels" ~1 μm² in area. Additionally, the information rich nature of the SERRS spectrum allows multiple levels of detection to be embedded into each pixel, further increasing the information depth of the array. By moving from micro- to nano-scale features, sensor chips can contain up to 105 times more information, dramatically increasing the capacity for disease screening.

Precision nanoscale deposition is a fundamental requirement for nanoscience research, development, and commercial implementation. Dip Pen Nanolithography(R) (DPN) is an inherently additive SPM-based technique which operates under ambient conditions, making it suitable to deposit a wide range of biological and inorganic materials. This technique is fundamentally enabled by a portfolio of MEMS devices tailored for microfluidic ink delivery, directed placement of nanoscale materials via actuated cantilevers, and cm2 tip arrays for high-throughput nanofabrication. Multiplexed deposition of nanoscale materials is a challenging problem, but we have implemented InkWells^(TM) to enable selective delivery of ink materials to different tips in multiple probe arrays, while preventing cross-contamination. Active Pens^(TM) can take advantage of this, directly place a variety of materials in nanoscale proximity, and do so in a "clean" fashion since the cantilevers can be manipulated in Z. Further, massively parallel two-dimensional nanopatterning with DPN is now commercially available via NanoInk's 2D nano PrintArray(TM), making DPN a highthroughput, flexible and versatile method for precision nanoscale pattern formation. By fabricating 55,000 tip-cantilevers across a 1 cm² chip, we leverage the inherent versatility of DPN and demonstrate large area surface coverage, routinely achieving throughputs of 3×107 μm² per hour. Further, we have engineered the device to be easy to use, wire-free, and fully integrated with the NSCRIPTOR's scanner, stage, and sophisticated lithography routines. In this talk we discuss the methods of operating this commercially available device, and subsequent results showing sub-100 nm feature sizes and excellent uniformity (standard deviation < 16%). Finally, we will discuss applications enabled by this MEMS portfolio including: 1) rapidly and flexibly generating nanostructures; 2) chemically directed assembly and 3) directly writing biological materials.

Microfluidic devices are currently being utilized in many types of BioMEMS and medical applications. In these systems, the interaction between the surface and the biological specimen depends critically on surface properties. The surface roughness and chemistry as well as the surface area to which the biomolecules or cells are exposed affect this interaction. Modification of the surface of microfluidic channels can improve the operation of the device by influencing the behavior of the biological specimens that are flowing through it. SU-8 is an epoxy-based, negative photoresist that has been previously used to create covered channels. Once cured, it is both chemically and thermally stable. It is also optically transparent above 360 nm, which allows optical measurements, including fluorescence imaging, to be taken inside the channel. SU-8 microchannels have been fabricated with a porous layer on the sidewalls by the photo-lithographic process, which is reproducible with precisely controlled channel dimensions. In order to attain these porous sidewalls, no additional fabrication steps are required outside the standard photo-lithographic process. The porosity of the sidewalls is a result of incomplete cross-linking of the polymer. The obtained porous surfaces can be specially treated to provide conditions preferable for biological interactions. The porous layer increases the internal surface area available on the sidewalls, which make these microfluidic channels preferable for biological applications. This paper describes the details of the fabrication process and the experiments that verify the benefit of using SU-8 microchannels with porous sidewalls.

A robust optical sensor for liquid control in fluidic channels is reported. The sensor operates on light intensity modulation resulting from alteration of total internal reflection into partial reflection. When a liquid guided in a channel covers an integrated prism, the total internal reflection is changed into a partial reflection, resulting in an intensity modulation of the reflected light. The set-up comprises a fibre which is built in a coupler unit with integrated LED and photodiode as well as a prism micro-machined directly into a micro-fluidic polymeric channel by laser ablation. The Prism is of 45-90-45° type with a dimension of 0.5 mm × 1 mm × 2 mm. In this design the radiation of the LED light source is transmitted and collected from the prism by a 50:50 fibre coupler by means of total or partial internal reflection. The sensor was characterised by filling alternately the channel with water and air. The influence of stray light onto the sensor signal was tested by applying a strong uncollimated illumination of the channel. Only a small increase in the output signal level in the presence of air but a strong increase in case of the presence of water could be detected.

Point-of-care devices represent the future for medical technologies. Current diagnostic tools are cumbersome, expensive, complicated, and often at risk for contamination. There is a need for cost effective, portable, closed-system, high-speed cell screening and cell isolating device. A microfabricated, exponentially-staging, BioMEMS microfluidic cytometer/cell sorting device offers these advantages over current technologies. A two-stage branched architecture allows the study of inter-particle spacing, flow relations, pressure measurements, and cell behavior in an environment where fluorescence detection is used to identify and analyze certain cellular characteristics. This device was microfabricated using the polymer PDMS to transmit light effectively, to be inexpensive and disposable, and to be easy to manipulate. For initial prototyping, an inverted fluorescent Nikon microscope provided the necessary excitation to view the particles and cells. For the portable device, avalanche photo diodes (APDs) and light emitting diodes (LEDs) are being incorporated into the device for the detection and excitation respectively. For low light level applications, sigma-delta modulation methods are being applied to reduce noise susceptibility and to detect the APD signal more efficiently. In addition, a data acquisition system (DAQ) has been designed that can effectively track signals from a cell sorter using a digital signal processing (DSP) board and a laptop computer. Currently elastomeric valves for diverting flow have been incorporated into the microfluidic chip. Measurements are being made of the effects of the microfluidics valve structures, or the simple opening and closing of selected channels to divert flow and cells down specific channels depending on their measured properties.

A microfluidic system for cancer diagnostics based around a core MEMS biosensor technology is presented in this paper. The principle of the MEMS biosensor is introduced and the functionalisation strategy for cancer marker recognition is described. In addition, the successful packaging and integration of functional MEMS biosensor devices are reported herein. This ongoing work represents one of the first hybrid systems to integrate a PCB packaged silicon MEMS device into a disposable microfluidic cartridge.

The Tumor MicroEnvironment for Metastasis (TMEM) is a critical determinant which will presage the evolution of primary tumors and the resulting metastatic dynamics. Primary tumor cells up and down regulate certain genes which increase motility and cause a disregard for positional information. We report on the development of a new tool for the documentation of cancer cell migration (initial targets: the rat mammary adenocarcinoma cell lines MTLn3 with an over expression of Mena+++). This tool, the NANo IntraVital Device (NANIVID), is a multi-functional nanosystem composed of a chemoattractant source (hydrogel-EGF), capsule (cell trap), counter (transparent, interdigitated electrode arrays for sensing cell arrival), and remote reporter (readout electronics). The device will be retrieved from the tumor site and the cells will be expelled for subsequent assay. The NANIVID will be used in conjunction with the current catheter-based approach in which a needle is loaded with a chemoattractant source and injected into the tumor. A major drawback in the catheter approach is the short cell collection time and lack of real time registering and reporting of cell arrival. This paper will present the current status of the NANIVID prototypes developed in which a transparent implantable device is loaded with chemoattractant source and placed near candidate mammary gland tumors in an established rat model for multiple days or weeks. This series of experiments will allow the comparison of methods and to benchmark the NANIVID for use in research. Initial results of these experiments and NANIVID design modifications will be presented.

This paper examines the necessary technologies to be mastered in order to build a practical micro array-based immunoassay cassette and its processing station for protein analysis. The interdependence of surface-chemistry, dye stability and imaging are outlined showning why a treated 100 nm film of Nitrocellulose adhered by an intervening layer to glass offers an efficacious surface for immobilizing an array of protein probes. The properties of a storage surface to support in desiccated form, fluidize and transport additional reagents are outlined and a practical solution proposed. Wet and Dry imaging are compared. The steps and functions expected for an assay platform comprising processing station and biochip cassette are identified. The performance of a successful bench-top automated multiplex immunoassay system is briefly described

Ricin is an easily available toxin which can be used as a bio-terror agent. Fast and inexpensive methods for its detection in different samples are needed. Recently we have developed a novel fluorescent sandwich immunoassay for ricin using magnetic-luminescent nanoparticles (MLNPs) as carriers in a microcapillary system for incubation and detection. Antiricin antibody coated MLNPs that were dispersed in buffer solution were introduced in the capillary tube and immobilized inside using an external electromagnet. Then the sample containing ricin was injected while the MLNPs were mixed by an alternating magnetic field. After the incubation, washing solution and secondary antibody conjugated with Alexa-fluorescent were injected into the capillary while the MLNPs were constantly mixed. After the final wash, the particles were immobilized for detection. The total analysis time was reduced to less than forty minutes which is about 8-10 fold improvement in comparison with the plate-based protocols. This system is promising for the development of a portable biosensor and can be used for the detection of other analytes of interest.

The ability to accurately measure the mobility of particles at low concentrations in small volumes is very useful for a broad range of applications. The coupling of micro- and nano-fluidic devices and confocal microscopy offers an efficient and rapid technique for multiplexed single molecule detection and analysis. Microfluidic channels at micron and sub-micron scales were designed and fabricated on fused silica wafers. Fluorescence correlation spectroscopy and fluorescence lifetime were applied to measure and analyze the mobility of fluorescent species in micro-droplets, micro-channels, and nano-channels. The experimental results show

Continuous-flow PCR has proven to be a powerful method for the amplification of genetic material due to its high speed and the possibility to perform amplicon detection and separation on-chip. A unique possibility of this method is the simultaneous amplification of several samples within a single chip by sample stacking, either having identical samples in several sample plugs separated by e.g. a mineral oil or using different samples in each sample plug. We have demonstrated the viability of sample stacking with a commercially available continuous-flow PCR system with a variety of protocols and samples. Further integration steps like thermal lysis and on-chip lyophilisate storage have been performed, with subsequent successful PCR. Chip modules for DNA extraction either with magnetic beads or membrane filters have been developed.

This contribution describes objectives and technology of the European LabOnFoil project, which combines 15 partners from 8 different countries for development of ultra-low-cost lab-on-chip systems and validation of the technical results in four different applications. The novel approach of the project is the combination of optoelectronic circuits which monolithically integrated light emitter and detector by OLED-on-CMOS deposition with microfluidic parts manufactured in SU8 on wafer-scale level. The future mass production of these novel diagnostic components will be guaranteed by the development of manufacturing equipment. This will provide, at last, a standardized solution to manufacture truly ultra-low-cost Lab-on-a-chip microsystems.

This paper presents a micro flow cytometry device fabricated using Ultra Violet (UV) lithography of the negative tone photo resist SU-8. A diamond-shaped sample injection nozzle, a three-dimensional hydro-focusing unit, and an optical detection unit with integrated out-of-plane microlens were fabricated using tilting lithography techniques. In addition to a 60° horizontal focusing angle, 30° slopes were designed and fabricated in the vertical direction of the hydro-focusing chamber. This unique design makes the hydro-focusing unit presented in this paper a truly three-dimensional one instead of the two-dimensional ones usually reported in literature. In the optical detection unit, a multi mode optical fiber was used to collect fluorescent or scattering light from the sample. To improve detection efficiency, out-of-plane microlens made of cured SU-8 polymer was imbedded in one of the outlet fluid channel walls. Numerical simulations were conducted to analyze the optical system and optimize the distances between optical elements to achieve best light coupling efficiency using commercial optical design software Zemax.

This paper presents a sensitivity evaluation of a love wave sensor with multilayer structure consisting of polymethyl methacrylate (PMMA)/SiO₂/41^o YX LiNbO₃. A theoretical model is presented to describe wave propagation in love wave devices with multilayered structure on large piezoelectric substrate. A complex dispersion equation expanded into Taylor series was presented to describe the lossy mechanism of the PMMA layer. Using the gold film as the sensitive interface, the mass loading sensitivity of the love wave sensor for biochemical application was evaluated theoretically, and the effects from the SiO₂ and PMMA on the sensor sensitivity were investigated to allow the design of an optimized structure. From the calculated results, the optimal thicknesses of SiO₂ and PMMA in the multilayered structure were determined, and the sensitivity comparison between love waves in LiNbO₃/SiO₂/PMMA and LiNbO₃/PMMA was studied, which shows that there is larger mass loading sensitivity in love wave devices with multilayered structure.

We reports on a novel microfluidic chip with polyelectrolytic gel electrodes (PGEs) used to rapidly count the number of red blood cells in diluted whole blood. The number and amplitude of dc impedance peaks provide the information about the number and size of red blood cells, respectively. This system features a low-voltage dc detection method and noncontact condition between cells and metal electrodes. The performance of this PGEs-based system was evaluated in three steps. First, in order to observe the size-only dependence of the impedance signal, three different sizes of fluorescent microbeads were used in the experiment. Second, the cell counting performance was evaluated by using 7.2 μm fluorescent microbeads, similar in size to red blood cells, in various concentrations and comparing the results with an animal hematoanalyzer. Finally, in human blood sample tests, intravenously collected whole blood was just diluted in a phosphate buffered saline without centrifuge or other pretreatments. The PGEs-based system produced almost identical numbers of red blood cells in over 800-fold diluted samples to the results from a commercialized human hematoanalyzer.

A 440MHz wireless and passive surface acoustic wave (SAW) based chemical sensor was developed for simultaneous measurement of CO₂ gas and relative humidity (RH) using a reflective delay line pattern as the sensor element. The reflective delay line was structured by an inter-digital transducer (IDT) and several shorted grating reflectors positioned both sites of the IDTs along the SAW propagation direction. A Teflon AF 2400 film with large solubility, permeability, and selectivity towards to CO₂ and a hydrophilic SiO₂ layer for water vapor sensing are used as the sensitive film and deposited onto the piezoelectric substrate. A simulation on the SAW device was performed using the coupling of modes (COM). The measured reflection coefficient S₁₁ in time domain of the fabricated SAW device shows sharp reflection peaks with high signal-to-noise (S/N) ratio, small signal attenuation, and few spurious peaks. During the CO₂ and humidity testing, high sensitivity (~2^o ppm^-1 for CO₂ detection and 7.45^o/%RH for humidity sensing), good linearity and repeatability were observed in the CO₂ concentration of 50~400ppm and humidity of 20~80%RH. Temperature and humidity compensations were also investigated during the sensitivity evaluation process.