Posters will be displayed in the room adjoining the presentation hall on Tuesday during breaks and at 5:30-6:30. All attendees are invited to visit the posters and talk with the authors. Refreshments will be served.
Poster abstracts are listed here in alphabetical order by the last name of the presenter.
Application of optical doppler tomography to two-fluid flows
Yeh-Chan Ahn, Woonggyu Jung, Jun Zhang and Zhongping Chen
Beckman Laser Institute, University of California, Irvine
As the imaging speed of Optical Coherence Tomography (OCT) and Optical Doppler Tomography (ODT) increases, a new horizon to access dynamical systems with fast transients will be open near future. The objective of this research is to demonstrate its potential to measure simultaneously the structure and velocity information of dynamical systems. Transient two-fluid mixing and gas-liquid two-phase flow in microfluidic devices are good examples to display clearly the advantages of ODT over other techniques.
Poster presenter: Yeh-Chan Ahn, ahny@uci.edu
The specific aims of this work are to:
(1) investigate the laminar dispersion in a microchannel and characterize important physical parameters such as streamwise velocity, secondary streamline, sedimentation time scale, and shear dispersion.
(2) investigate the chaotic mixing in a barrier embedded Kenics mixer and demonstrate its mixing pattern and high mixing performance.
(3) investigate the gas-liquid two-phase slug flow which is the most common flow regime in two-phase flow in microchannel and measure void fraction, bubble frequency, bubble and liquid velocities, and interfacial area concentration to determine interfacial transports.
HIBALIS: a Prototype System for Intelligent Human Sensing
Masaki Aono, H. Takao, K. Sawada, M. Kitazaki, A. Wakahara, S. Ichikawa, S. Nakauchi, S. Kuriyama, T. Hirotsu, K. Katsurada, S. Shinohara, Y. Sekiguchi, Y. Yasuda, Y. Iribe, T. Nitta, and M. Ishida.
Toyohashi University of Technology
Toyohashi University of Technology (TUT) in Japan, has carried out an "Intelligent Human Sensing" project for several years as a 21st Century Center of Excellence (COE) project sponsored by the Japanese government. In this project, we are implementing a smart classroom called HIBALIS, where a lecturer and students can interact with each other, while the lecturer can monitor the mental state as well as observe physical biosignals from sensor devices attached to each student in real time. We will present HIBALIS architecture from both hardware, including "Smart-chair" and "Smart microchip" sensors, and software aspects.
Poster presenter: Masaki Aono, aono@ics.tut.ac.jp
Sensing of the Environment by Mesoporous Photonic Crystals
Alexander Baryshev
Toyohashi University of Technology
Artificial structures composed of closely packed monodisperse silica spherical particles (synthetic opals and opal thin films) are used as representatives of 3D photonic crystals. We have shown that optical properties of opal thin films are extremely sensitive to the external conditions of experiment, and in the first turn, to air humidity. This is due to inherent to mesoporous film microstructure. The sensing mechanism based on probing of optical transmissivity in the vicinity of photonic stop bands is shown to provide fast sensing performance. High sensitivity, quick response and possibility of contactless measurements makes sensors based on optical effects in mesoporous PCs very promising, in particular, for remote sensing. It concerns not only humidity sensors, but also sensors of various gases, temperature, deformation, and so on.
Poster presenter: Alexander Baryshev, alex_baryshev@maglab.eee.tut.ac.jp
Fabrication of Flexible Organic Thin Film Transistor for Sensing Devices
Gee Keun Chang (1), Ho Jung Chang (1), Mark Bachman (2) and G. P. Li (2)
1-Department of Electronics Engineering, Dankook University, Cheonan 330-714, Korea; 2-Integrated Nanosystem Research Facility, U.C, Irvine, Irvine, CA 92697, USA
The organic thin film transistors (OTFTs) based on conjugated polymers and other molecules have been attracted much attention to substitute the main stream thin film transistors using inorganic silicon materials. OTFTs have a great potential for the application of genetic sensing device which enables to determine the base sequence of the target DNA through molecular recognition at the gate insulating film. Until now, OTFTs have some obstacles to accelerate the commercialization of high frequency switching devices due to relatively low carrier mobility and poor reliability. In this study, the organic thin film transistors on plastic substrates were prepared and characterized to improve the mobility as well as the sensitivity of the sensing devices. The series of polyvinyl, poly-4-vinyl phenol (PVP) was used as solutes and propylene glycol mono-methyl ether acetate (PGMEA) used as a solvent for the formation of organic insulating film in the OTFT devices. In addition, the cross-linking of organic insulators was attempted by adding the thermosetting poly(melamine-co-formaldehyde) as a hardener material. Finally, the inverted staggered OTFTs using cross-linked PVP as a gate insulator were fabricated on the plastic substrate. The field effect mobility of the prepared OTFT showed about 0.23 cm2/Vs.
Poster presenter: Ho Jung Chang, hjchang@dankook.ac.kr
Microfluidic Approach for Polymeric Particle Synthesis
Kyung Choi (1)
Department of Chemistry, University of California, Irvine
Since chemists have sought for new advances in nanotechnology by designing novel molecular structures, development of polymer nano-particles has been widely studied to satisfy our growing demands in miniaturization. We introduce here the design and operation of microfluidic reactors specifically for polymer particle synthesis by taking advantages of microscale mixing. The use of microfluidic reactors offers a number of potential advantages over excising conventional synthetic routes.
Poster presenter: Kyung Choi, choikm@uci.edu
Human neural stem cell growth and differentiation in a gradient-generating microfluidic device
Bong Geun Chung (1), Lisa A. Flanagan (2), Seog Woo Rhee (1), Philip H. Schwartz (3,4), Abraham P. Lee (1), Edwin S. Monuki (2), and Noo Li Jeon (1)
1-Department of Biomedical Engineering, Henry Samueli School of Engineering; 2-Department of Pathology, College of Medicine; 3-Department of Developmental and Cell Biology, School of Biological Sciences, University of California Irvine, Irvine, CA, USA; 4-National Human Neural Stem Cell Resource, Children's Hospital of Orange County Research Institute, Orange, CA, USA
This paper describes a gradient-generating microfluidic platform for optimizing proliferation and differentiation of neural stem cells (NSCs) in culture. Microfluidic technology has great potential to improve stem cell cultures, whose promise in cell–based therapies is limited by the inability to precisely control their behavior in culture. Human NSCs from the developing cerebral cortex were cultured for more than 1 week in the microfluidic device while constantly exposed to a continuous gradient of a growth factor mixture. NSCs remained healthy throughout the entire culture period proliferated and differentiated in a graded and proportional fashion that varied directly with GF concentration.
Poster presenter: Bonggeun Chung, bonggeuc@uci.edu
Human Neural Stem Cell Migration in a Gradient-Generating Microfluidic Chamber
Bong Geun Chung (1), Franz-Josef Mueller (2,3), Jean Pyo Lee (2), Josef P. Aldenhoff (3), Evan Y. Snyder (2), Jeanne F. Loring (2), Philip H. Schwartz (4,5), Noo Li Jeon (1)
1-Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA; 2-The Burnham Institute, Regeneration and Stem Cell Program, La Jolla, CA, USA; 3-Center for Integrative Psychiatry, (ZIP) Kiel, SH, Germany; 4-Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, USA; 5-National Human Neural Stem Cell Resource, Children’s Hospital of Orange County Research Institute, Orange, CA, USA
During morphogenesis, neural stem cells (NSCs) encounter complex positional cues whose intricate interplay is crucial for brain development. NSCs also appear to be recruited into pathological processes. We identified the chemokine stromal cell-derived factor-1 as one of the key factors governing localization of human NSCs transplanted to animal models of stroke. However, chemokine and ligand expression in development is complex. In order to dissect multiple factors guiding NSC migration, we are investigating the response of cultured NSC molecular cues using a novel gradient-generating microfluidic platform. Our results indicate NSCs showed non-random movement in response to both chemoattractants and neuroinflammation-derived molecules.
Poster presenter: Bonggeun Chung, bonggeuc@uci.edu
SERS nanotags: multiplexed nanoscale optical detection labels that span the gap between point-of-care and central lab diagnostic technologies
Peter Corish
Oxonica, Inc., Mountain View, CA
This poster will describe point-of-care applications of surface enhanced Raman scattering (SERS) nanotags, a powerful new optical detection label that can be used across the spectrum of in vivo and in vitro clinical diagnostics. Key features of SERS nanotags include: (a) 785 nm excitation, allowing interrogation in complex tissue and/or whole blood samples; (b) excellent sensitivity; (c) high-level multiplexing due to the spectral narrowness of Raman bands; and (d) excellent stability and biocompatibility, afforded by the inert silica shell. Data from multiplexed lateral flow immunoassays and no-wash, in-the-tube assays will be showcased.
Poster presenter: Peter Corish, peter.corish@oxonica.com
Epithelial Injury Influences Angiogenesis Through a TGF-â2-dependent Mechanism in Vitro
David T Truong, H. Garrett R. Thompson, Craig K. Griffith, Steven C. George
1-Department of Biomedical Engineering; 2-Department of Chemical Engineering and Materials Science, University of California, Irvine
Asthma is an inflammatory disease of the bronchial airway characterized by chronic intermittent airway constriction, epithelial injury, and tissue remodeling including angiogenesis. A tissue engineering approach modeling the pulmonary mucosa offers a valuable opportunity to study this phenomenon. The current study developed an in vitro 3-D model of the human airway to analyze capillary sprout formation in response to conditions of epithelial injury. The model consists of a differentiated, confluent monolayer of Normal Human Bronchial Epithelial Cells (NHBE) cultured in an air-liquid interface atop a porous membrane suspended above fibrin-embedded, Human Umbilical Vein Endothelial Cell (HUVEC)- coated beads. Normal Human Lung Fibroblasts (NHLF) are seeded on the fibrin gel at a distance allowing sufficient diffusion of soluble mediators promoting capillary maturation. Characterization of angiogenesis is defined by total capillary network length, number of vessel sprouts per bead, and number of vessel segments. Because past studies have shown injury to the epithelium alters its release of soluble mediators such as TGF-â2, we hypothesized that wounding of the epithelium adversely affects angiogenesis. The presence of the vascular epithelium itself inhibits capillary sprouting in vitro independent of TGF-â2, a cytokine previously found to be important in the tissue construct. Injury to the epithelium significantly decreases angiogenesis but significantly increases angiogenesis in the presence of TGF-â2 antibody. Injury to the epithelium also greatly increases VEGF secretion but has no significant effect in the presence of TGF-â2 antibody. Together, this data suggests epithelial injury modulates angiogenesis via a TGF-â2 dependent mechanism.
Poster presenter: Truong David, dttruong@uci.edu
Vertical ZnO Nanowire Array for Integrated Nanoscale Electronics and Optoelectronics
Deepanshu Dutta
Department of Materials Science & Chemical Engineering, University of California, Irvine
Semiconducting nanowires have attracted tremendous amount of research interest for their potential applications in integrated nanoelectronics and nano-optoelectronics. To fully utilize their shape anisotropy, vertically-aligned nanowires enable the potential to form a three-dimensional (3D) architecture. In addition, the lateral ordering of the vertical nanowire array can be achieved at the same time so that the individual nanowires can be addressed and used as active charge transport channel or sub-wavelength waveguide. In our work, highly ordered vertical ZnO nanowire array with a density of ~1010 cm-2 was successfully fabricated into hexagonally structured nanopores in anodic alumina membrane (AAM) via chemical vapor deposition (CVD) in conjunction with electrodeposition method. The electrical transport property and photoconduction of the individual vertical nanowires were investigated with atomic force microscopy (AFM). These studies pave the way for constructing highly integrated nanowire-based electronic and optoelectronic circuits, such as ultrafast logic gates, high density memory storage, high resolution display and imaging sensor.
Poster presenter: Deepanshu Dutta, ddutta@uci.edu
Magnetic Field sensitivity of magnetophotonic Crystals
Rintaro Fujikawa (1), Kazuhiro Tanizaki (1), Alexander Baryshev (1, 2), Kwang-Ho Shin (1), Pang Boey Lim (1), Hironaga Uchida (1), Mitsuteru Inoue (1, 3)
1-Department of Electrical and Electronic Engineering, Toyohashi University of Technology; 2-Ioffe Physico-Technical Institute, Russian Academy of Sciences; 3-CREST, Japan Science and Technology Corporation
Magnetophotonic crystals (MPCs), combination of photonic crystals (PCs) and magnetic materials, are paid much attention due to their huge enhancement of magneto-optical effect. We have investigated one-dimensional magnetophotonic crystals (1D-MPCs), composed multi layers of SiO2 and Ta2O5 with Bi:YIG film as a defect layer. Due to their magnetic defect layer, Faraday rotation angle could be enhanced in the localize mode. In this work, we have investigated the possibility of application of magnetophotonic crystals as a magnetic field sensor, which is not connected with any wires. The structure of 1D-MPC was (Ta2O5/SiO2)5/Bi:YIG/(Ta2O5/SiO2)5 on a fused quarts substrate. With this unique structure, the Faraday rotation reached to one hundred times larger than that of single layer Bi:YIG polycrystal film.
Poster presenter: Rintaro Fujikawa, fujikawa@maglab.eee.tut.ac.jp
Carbon MEMS: Key to Energy Miniaturization
F. Galobardes, B.Y. Park, G. Turon, R. Zaouk, C. Wang, M. Madou
Department of Mechanical and Aerospace Engineering, University of California, Irvine
Integration of functionality and the miniaturization of portable devices are driving forces for the reduction in size of energy sources such as batteries, fuel cells and ultracapacitors. Unfortunately, conventional fabrication techniques do not scale down to the scale lengths that are required for the manufacturing of micropower devices. Carbon-MEMS core technology allows unprecedented control over shaping of micro and nanoscale carbon structures. Various microscale carbon structures for power devices are presented. If has been found that C-MEMS carbon intercalates lithium ions and is a suitable material for lithium ion batteries. Fuel cell and bio fuel cell devices have also been fabricated and demonstrated.
Poster presenter: Francesc Galobardes Jornet, fgalobar@uci.edu
A microfluidic culture platform for CNS axonal injury, regeneration and transport
Anne M. Taylor (1), Mathew Blurton-Jones (2), Seog Woo Rhee (1), David H. Cribbs (2), Carl W. Cotman (2), and Noo Li Jeon (1)
1-Department of Biomedical Engineering; 2-Institute for Brain Aging and Dementia, University of California at Irvine
Axonal damage is critical to the etiology of CNS injuries and neurodegenerative disease (e. g., spinal cord injury and Alzheimer’s disease); therefore, considerable effort focuses on the molecular and cellular mechanisms that influence axonal plasticity and response to injury. In vitro models facilitate the study of axonal
Poster presenter: Joseph Harris, jwharris7@gmail.com
biology in the peripheral nervous system (PNS), but no suitable method has been developed for the CNS because of the challenges associated with culturing CNS neurons. Using microfabrication and soft lithography we have fabricated a microfluidic culture platform that polarizes and isolates CNS axons from cell bodies and dendrites. We illustrate several experimental paradigms for investigating axonal biology using this platform.
Measurements of dynamic neural activity from multiple fields of the auditory cortex of guinea pigs using an optical recording method: an application of advanced measurement technology to neuroscience
Junsei Horikawa and Shunji Sugimoto
Department of Knowledge-Based Information Engineering, Toyohashi University of Technology
In order to study how a mass of neurons interacting with each other contribute to auditory information processing, we have measured neuronal activities in the guinea pig auditory cortex in-vivo for over 10 years, using an optical recording method with a voltage-sensitive dye. Owing to development of technology, pixels of a photosensor array in an optical recording equipment have been increased from 12 x 12 (photodiode) to 100 x 100 (MOS sensor). We report recent optical recording measurements showing dynamic neural activity in the multiple fields of the auditory cortex in response to sound stimulation.
Poster presenter: Junsei Horikawa, horikawa@tutkie.tut.ac.jp
Non-viral Liposomal Carrier Fabrication by Integrated Micro-mixer and Micro-incubator System
Albert Tsung-Hsi Hsieh, Yuh Adam Lin, Jen-Hao Pan, Abraham P. Lee
Department of Biomedical Engineering, Unversity of California, Irvine
A non-viral and efficient carrier for the applications delivering drugs, plasmic DNA, shRNA for pharmaceutical and therapeutic applications is presented. The cationic lipid based liposomal carriers which has been the most attractive non-viral solution. The size of complexes of cationic lipid and DNA (lipoplex) dictates the efficiency of gene transfection. Moreover, the order of mixing of cationic lipid and DNA, mixing rate, and mixture incubation time are factors that determine the lipoplex sizes during sample preparation. We developed a Picoliter Micro Reactor and Incubator (PMRI) system to formulate monodisperse cationic lipids and DNA complexes. The monodisperse micro reactor and incubator was designed and fabricated based on the microfluidic droplet formation devices which our lab and others developed. Compared with the conventional irreproducible lipoplex preparation using hand-shaking or vortexing processes for mixing, the PMRI system we developed for lipoplex formulation demonstrates the ability of rapid and uniformly mix cationic lipid and DNA simultaneously, and generates a narrower size distribution peak and smaller average size. The PMRI also enables the mixing and incubation integrated process and lipolex formulation reproducibility.
Poster presenter: Albert Tsung-Hsi Hsieh, tsung@uci.edu
Using Microchannel Geometry Induced Picoliter Droplet Mixing to Improve the Nucleic Acid Detection Rate by Molecular Beacon
Albert Tsung-Hsi Hsieh, Patrick J. Pan, Abraham Lee
Department of Biomedical Engineering, University of California, Irvine
We report a preliminary result of rapidly detecting nucleic acid in picoliter droplets by encapsulating FRET (Fluorescence Resonance Energy Transfer) molecules and nucleic acid in the picoliter droplets. We use one class of FRET molecule- molecular beacon (MB) as our DNA sensor in this research. The DNA detection rate is faster than conventional detection which MB molecule binds to ssDNA through diffusion reaction. The different shapes of microchannel will induce different mixing rates or MB hybridization rates in microdroplet. Experiments are carried out in different shapes of microchannel and different concentrations of target DNA to compare the detection rates. The sensing system is rapid, simple, and only a few micro liters of sample are required. It also can future integrate with other micro- droplet based biomolecules analysis system, such as PCR and cell lysis etc..
Poster presenter: Albert Tsung-Hsi Hsieh, tsung@uci.edu
Proliferation and Apoptosis of Mouse Neural Stem Cells in a Microfluidic Morphogen Gradient Platform
Jia Sheng Hu* (1), Bong Geun Chung* (2), Noo Li Jeon (2), Edwin S. Monuki (1)
1-Department of Pathology; 2-Biomedical Engineering, University of California Irvine, CA, USA, *Co-lead authors
Morphogen gradients are fundamental to animal development, and morphogen defects are primary causes of human brain malformations. Nonetheless, tremendous controversy remains about the mechanisms by which morphogen gradients act on the developing brain. In order to overcome biological limitations of natural gradient models, we have developed a microfluidic gradient chamber that can closely mimic the morphogen gradient profiles seen in living organisms. To take full advantage of this microfluidic platform, we are developing real-time optical assays to measure proliferation and cell death of cultured cells exposed to the naturally-occuring morphogen, BMP4. This platform should not only advance understanding of brain development, but also provide a versatile tool with multiple basic and clinical applications.
Poster presenter: Jia Sheng Hu, jshu@uci.edu
Microfluidic-Based Solvent Evaporation and Solvent Extraction Approaches for PLGA Micro/Nanosphere Generation
Lung-Hsin Hung (1), Rita Kuo (2), and Abraham Philip Lee (1,3)
1-Department of Biomedical Engineering; 2-Department of Electrical Engineering and Computer Science; 3-Department of Mechanical and Aerospace Engineering, University of California at Irvine
Here two microfluidic approaches for continuous synthesis of poly (lactide-co-glycolide) (PLGA) micro/nanospheres for drug delivery and protein coating applications are presented. The micro chips utilize solvent evaporation and solvent extraction methods to generate homogeneous PLGA spheres and have the ability to control PLGA sphere size by adjusting input flow rates. The mini-stirrer assembled at the outlet reservoir prevents aggregation. The size of generated PLGA spheres range from 20um to 300nm. Compared to conventional methods, the microfluidic droplet reactor technique provides high repeatability and generation efficiency; the generated PLGA spheres can be coated with reagents or proteins for drug delivery applications.
Poster presenter: Lung-Hsin Hung, lhung@uci.edu
Micro Scale Chip-based PCR System for Detection of Hepatitis B Virus
W. Kang, S. B. Park, Y. H. Nam, Y. C. An, S. H. Lee, J. K. Park, W. C. Jang(1), S. M. Park(2), S. C. Chong(3)
1-Dept. of Chemistry, School of Advanced Science and Basic Science Research Institute Dan-kook University, Cheonan 330-714, Korea ; 2-Dept. of Genet Bio of Biotech B.I. B, Dankook University, Cheonan 330-714, Korea ; 3-Samsung Techwin, Sungnam 462-121, Korea ;
Quantitation of salmonella is important for monitoring disease progression and for assessing the response to antibacterial therapy. We investigates a rapid Micro-PCR assay for salmonella that can simultaneously detect and quantify this organism in the laboratory. The objective of this study was to develop and evaluate compared to RT-PCR method for the detection of salmonella. All methods had undiluted(1.6 X 108 copy/§¡), 10-1,10-2,10-3,10-4,10-5 of salmonella DNA were amplified by Micro-PCR and RT-PCR to determine the sensitivity of the assay.
Poster presenter: Won-Cheoul Jang, wcjang@dankook.ac.kr
The results show that Micro-PCR and RT-PCR assay combine rapidity, sensitivity and reproducibility for salmonella DNA quantitation in an high dynamic range of quantitation. However, Micro-PCR assay has the advantages of more rapid amplification, simple operation, needs to reagent of a small quantity and will be useful for rapid clinical diagnosis of salmonella.
Micropallets for Microfluidics: An Approach to Biological Assays
Cynthia Jensen-McMullin, Stephen Ng, G.-P. Li(1) & Mark Bachman(1) & Nancy Allbritton(2) & Chris Sims(2),
1-Department of Electrical Engineering and Computer Science; 2-Department of Physiology and Biophysics/Department of Biomedical Engineering, University of California, Irvine
We introduce the use of micropallet carriers. Micropallets are small carrier particles made of plastic or other material that are used to carry attached biological or chemical samples through a microfluidic system (e.g., DNA, RNA, proteins, antibodies, adherent cells, organisms). In microfluidic systems, micropallets enable functional multiplexed, programmable assays to be performed on materials not normally suited for microfluidic devices. Similar to conventional factory pallets that carry a product through an automated manufacturing line, micropallets are engineered to carry their cargo through a micro-scale system.
Poster presenter: Cynthia Jensen-McMullin, jensenc@uci.edu
DNA Array Hybridization in a Centrifuge-Based Microfluidic Platform
G. Jia (1), K.Ma (1), H.Kido (1), J.Zoval (1) , R. Peytavi (2), M.Bergeron (2) and M. Madou (1)
1-Department of Mechanical & Aerospace Engineering, University of California, Irvine; 2-Division of Microbiology and Infectious Diseases Research Center, Laval University, Canada
DNA hybridization is a mass transport-limited reaction. The hybridization step for most conventional DNA chips may require from 30 minutes up to several hours to complete, depending on the size and concentration of target DNA as well as the hybridization conditions. One of the effective approaches to accelerate the rate of DNA hybridization is to introduce the sample solution to the capture probes by flow so that mass transport can be shifted from pure molecular diffusion to a faster mode - convective diffusion. We have successfully implemented the flow-through hybridization scheme in an automated format in a centrifuge-based microfluidic platform in which centrifugal force is used for reagent propulsion and capillary force is used for liquid gating. The total assay time of less than 15 minutes for 368 bp staphylococcal amplicons was accomplished using this platform.
Poster presenter: Guangyao Jia, gjia@uci.edu
C-MEMS/NEMS for Bio-sensing Applications
M. Karthikeya(2), H. Xu(1), C. Wang (1), and M. Madou(1)
1-Department of Mechanical Engineering, 2-Department of Material Science, University of California, Irvine
A novel design and fabrication of glucose sensors based on high aspect ratio carbon post microarrays has been reported in this paper. Apart from the fact that carbon has a wide electrochemical stability window, one advantage of using carbon posts as working electrodes for the amperometric glucose sensor is its high surface area to volume ratio, greatly improving sensitivity of the glucose sensor. High aspect ratio carbon post electrode arrays were fabricated by carbon-microelectromechanical systems (C-MEMS) technology. Immobilization of enzyme onto the carbon electrodes was carried out through co-deposition of electrochemically polymerized polypyrrole (PPy) and glucose oxidase (GOx). Sensing performance of the glucose sensors with different post heights was tested and compared with that of the carbon film. The result demonstrates that the sensitivity is increased with the increase of the surface area, consistent with the hypothesis that the number of reaction sites scales with the active surface area of the sensor.
Poster presenter: Malladi Karthikeya , kmalladi@uci.edu
Rapid and automated sample preparation for nucleic acid extraction on a microfluidic CD (compact disc)
J. Kim (1), H. Kido (1), J. V. Zoval (1), D. Gagné (2), R. Peytavi (2), F. J. Picard (2), M. Bastien (2), M. Boissinot (2), M. G. Bergeron (2), and M. J. Madou (1)
1-Department of Mechanical & Aerospace Engineering, University of Irvine, 2-Centre de Recherche en Infectiologie de l’Université Laval, Québec, Canada
Rapid and automated preparation of PCR-ready genomic DNA was demonstrated on a multiplexed CD (compact disk) platform by using hard-to-lyse bacterial spores. Cell disruption is carried out while bead-cell suspensions are pushed back and forth in center-tapered lysing chambers by angular oscillation of the disk - keystone effect. Upon application of a remote heat to the disk in motion, the wax valves release lysate solutions into centrifuge chambers where cell debris are separated. Only debris-free DNA extract is then transferred to collection chambers by capillary-assisted siphon. Lysing capacity was evaluated using a real-time PCR assay to monitor the efficiency of Bacillus globigii spore lysis. PCR analysis showed that 5 minutes’ CD lysis run gave spore lysis efficiency similar to that obtained with a highly efficient DNA extraction kit. This work will contribute to the development of an integrated CD-based assay for rapid diagnosis of infectious diseases.
Poster presenter: Jitae Kim, jitaekim@uci.edu
Surface Modification of Si-Nanoparticle for Biomolecule Diagnosis
Yong Tae Kim (1), Young Hwan Kim(1), and Woon Jo Cho(2)
1-Semiconductor Materials & Devices Lab.; 2-Nano Device Research Center, Korea Institute of Science and Technology
Molecule detection and image sensing with semiconductor nanoparticles for cancer have been intensively investigated for nano and microsystem of medical diagnosis. In this work, we have controlled silicon nano-particle size from 1 to 5 nm and modified the surface of nano particles with hydroxyle, amine and carboxyl. With these methods, biotinylation, tethering, conjugation with streptavidine have been studied for detecting biomolecules. We will discuss the optical performance of silicon nano-paticles with surface tagging ligands.
Poster presenter: Yong Tae Kim, ytkim@kist.re.kr
Estimating human cognitive level by brain-activity sensing: SVM classification of calculation-task load using single-trial EEG
Michiteru Kitazaki (1, 2, 3), Akinori Nomura (3) , Kenta Uchio (4), and Shigeki Nakauchi (2, 4)
1-Research Center for Future Vehicle; 2-Intelligent Sensing System Research Center; 3-Department of Knowledge-based Information Engineering; 4-Department of Information and Computer Sciences, Toyohashi University of Technology
Technology for estimating human cognition by measuring brain activities is very important to develop a new human interface. We measured EEG at 19 points of human subjects when they were doing calculation of two digits (calculation condition) and they just saw them (control condition). A session (either calculation or control condition) took 20s for 20 trials (a calculation per second), and was repeated 16 times for each subject. We conducted FFT using every 6s data after eliminating the first and the last 1s data of each session. We made classification functions by SVM (support vector machine) using a half of sessions, and estimated cognitive load of the other (novel) data. We obtained 63-70 % correct within-subject data, and 54-61 % correct between-subjects data. It is suggested that we can estimate human cognition using brain activities with within-subject calibration.
Poster presenter: Michiteru Kitazaki, mich@tutkie.tut.ac.jp
Nanotextured self-rolled polymer micro-tubes
Y. P. Kong, A. F. Yee
Department of Chemical Engineering and Materials Science, University of California, Irvine
We report on a technique for fabricating nanotextures on curved, tubular polymer surfaces.
Poster presenter: Yen Peng Kong, Kongy@uci.edu
Biological cell behavior and locomotion in a two dimensional (2-D) in-vitro environment have been extensively studied. However, in reality, cells interact in-vivo with micrometer and nanometer features and structures in a three dimensional (3-D) extracellular matrix. Therefore researchers have been using collagen scaffolds, hydrogels, electrospun scaffolds and other 3-D extracellular matrix for mimicking materials for cell studies. Cells cultured in artificial 3-D extracellular matrices have exhibited cell behavior and interaction that is different from 2-D cell behavior but it is difficult to attribute such differences to specific dimensional scales, local compliance or chemical cues. This difficulty is in part due to the difficulty of characterizing these artificial matrices in the nanometer scale and also in part due to the difficulty of reproducing the position of specific cues in 3-D from sample to sample. To overcome these difficulties, one must be able to engineer a 3-D cell matrix to have specific local physical and chemical cues in a reproducible way.
We have fabricated self-rolled polymer microtubes having nanotextures on both inner and outer surfaces. These tubes can have diameters of roughly the size of a single cell or a cluster of cells and the inner and outer surfaces of the tubes can have various nanotextures. The length of these tubes can range from several mm to several cm. In this way, the behavior of a single cell to a cluster of cells can be examined.
We use a variation of nanoimprinting known as reversal imprinting to reproducibly form the nanotexture. A sacrificial polymer layer that also functions as a mold is first reversal imprinted onto a silicon wafer. Onto this sacrificial polymer mold, a poly(dimethyl siloxane) (PDMS) layer is spin coated and cured. The surface of this PDMS coating is then O2 plasma treated and a third layer of crosslinkable poly(vinyl alcohol) (PVA) is then reversal imprinted onto the PDMS layer. To form a tube, the sacrificial polymer mold is removed with a solvent and this solvent also swells the PDMS layer. The swelling induces a strain in the PDMS-PVA bilayer and this strain gives rise to a bending moment that rolls the PDMS-PVA bilayer into a tube. The strain arising from crosslinking PVA on PDMS also contributes to the bending moment and we will show that this is a better method of forming the nanotextured tubes.
Single-cell analysis on a surface-modified PDMS microfluidic device
Hsuan-Hong Lai (1), Shuwen Hu (2), Xueqin Ren (2), Mark Bachman (2, 3), Christopher E. Sims (4), Guann-Pyng Li (2, 3), Nancy Allbritton (1, 2, 4)
1-Department of Chemical Engineering and Materials Science; 2-Department of Biomedical Engineering; 3-Department of Electrical Engineering and Computer Science; 4-Department of Physiology and Biophysics, University of California, Irvine
Numerous studies have demonstrated that individual cells may seem identical but behave heterogeneously. Cellular constituents, chemical composition and biological activities may vary significantly from cell to cell. Consequently, the accurate measurement of most cellular properties requires monitoring of cells individually. In terms of separation techniques, capillary electrophoresis (CE) demonstrates great promise for the analysis of large numbers of single cells. We aim to miniaturize current methodology to a microfluidic platform. The benefits of this analytical system include a high-degree of automation, high throughput, small sampling capabilities, and low cost of analysis.
Poster presenter: Hsuan-Hong Lai, hsuanhol@uci.edu
Diffraction based lable-free biosensor using grating coupler on optical waveguide
Zhian Lai (1), Yuli Wang (2), Mark. Bachman (1), and G. P. Li (1) ,
1-Department of EECS, University of California, Irvine, 2-Department of Physiology & Biophysics, University of California, Irvine
We are developing a novel label-free biosensor to detect antibody/antigen binding events, based on grating coupler on optical waveguide. Protein submicron periodic structure can be fabricated on glass slide and the structure works as a grating coupler on optical waveguide. The grating depth is the thickness of the protein layer and it is one dominate factor of the light outcoupling efficiency. Antibody/antigen binding events change the protein layer thickness, therefore the grating depth and will affect the output coupling light intensity. We monitor the output coupling light intensity and use its change as a way to detect the binding events.
Poster presenter: Zhian Lai, zlai@uci.edu
A Novel Fluorescence Microscopy Method for Skin Measurements
C. Lee, R. Colyer, E. Gratton
Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine
Fluorescence lifetime imaging microscopy (FLIM) is a very powerful method to detect ion concentrations in cells and tissue and for the determination of FRET. FLIM has many advantages over fluorescence intensity imaging microscopy, particularly in inhomogeneous, biological systems. However, FLIM is not commonly used because of the high cost of the FLIM hardware, the difficulty in setting up an experiment, and the intricacies of data analysis. We have developed new hardware and new analysis method that has resolved these problems. The hardware is simple and inexpensive and the method of data analysis can be used by non-specialists.
Poster presenter: Claudia Lee, claudiyl@uci.edu
3D Nonlinear Finite Element Analysis of the Metal/Ceramic Interface in Ceramic Hip Replacements
Soo W. Lee and Daniel Carrillo
Department of Materials Engineering, Sun Moon University
The modularity of components for total hip replacement is a common feature of modern devices. This modular interlocking considers the impaction of the ceramic component during surgery, therefore it is locked through a taper with the metallic stem and a high stress interface is created. The aim of this investigation is to make several computer simulated models of the hip system in order to evaluate regions of stress concentration as well as the pressure and friction stresses in stern/ball junctions of total hip replacements. 3D Non-Linear Finite Element Analyses were performed taking into consideration a high peak load to simulate trauma conditions. Ball heads from 22 to 36 mm in diameter were modeled; also two sizes for taper lock were simulated to report their influence on the stresses over the critical areas of the ball head. Two different materials of common ball head ceramics were considered (Alumina and Zirconia) to evaluate their incidence on the stresses developed. The results from these analyses are given in the form of stress maps on the ball heads; such data may be useful for surgeons, patients, and designers because it shows a direct relationship between two important parameters on ball head design (diameter and bore) and material properties, on the stresses that can cause failure of the component when they are concentrated in small elements of volume. For the ball head design with deeper bore (of 19.5 mm), the stresses across the interface show a considerably smaller contour of up to 110 MPa, instead of 350 MPa found in a 13.5 mm cone design. The data obtained for the stresses in the stem/ball interface suggests that zirconia balls are more prone to suffer microsliding due to the low coefficient of friction between Ti-alloy and zirconia; therefore there is a higher risk of fretting corrosion in this combination.
Poster presenter: Soo W. Lee, swlee@sunmoon.ac.kr
An Integrated Electron Imaging System for Biomedical Applications
Shengdond Li (1), James Bouwer (2), Fred Duttweiler (2), Mark Ellisman (2), Liang Jin (2), Nguyen Xuong (2), Stuart Kleinfelder (1)
1-Department of Electrical Engineering and Computer Science, University of California, Irvine; 2-University of California, San Diego
High resolution imaging of biological assemblies such as proteins, viruses, and cells are important for biomedical diagnosis and drug discovery. We report the design and experiments of a new CMOS directdetection camera system for electron imaging. The active pixel sensor array includes 512 by 550 pixels,each 5 by 5 ìm in size, with an 8 ìm epitaxial layer to achieve an effective fill factor of 100%. Simulation, experimental designs, and measurements are presented to demonstrate trade-offs between charge-collection efficiency, signal-to-noise ratio, pixel size and diode area. Spatial resolution of 2.3 ìm for a single incident
Poster presenter: Shengdong Li, shengdol@uci.edu
e- has been measured, with 24 ìV per ionization e- sensitivity, 60 dB dynamic range and 70 frames/s readout. Electron microscope tests have been performed with 200, 300 and 400 keV beams, and high resolution images of a nerve cell’s myelin sheath are presented.
DNA-based Killer Automaton: An Innovative Nanomedicine
S. Liu, J-L. Gaudiot
Department of Electrical Engineering and Computer Science, University of California, Irvine
Based upon Shapiro's molecular automaton model, we propose the DNA-based Killer Automaton (DKA), an innovative nanomedicine for cancer treatment. Each DKA is composed of a DNA cancer detector and a cytotoxic chemical. Equipped with an internal DNA Computing algorithm, the DKA cancer detector checks the cell's mRNA to determine whether the cell is cancerous and releases the cytotoxin to eliminate the cell only if it is cancerous. In addition, due to the bystander effect, the cytotoxin carried by DKA will only diffuse to the cells that express cancerous behavior through homologous GJIC channels, thus completely eliminating cancer cell lines with minimal side effects. In order to predict the efficacy of DKA in cancer treatments, we have constructed a software model to simulate the DKA mechanism in an artificial multi-cell environment.
Poster presenter: Shaoshan Liu, shaoshal@uci.edu
Pyruvate dehydrogenase nanocage
Chengfei Lou, Sierin Lim, Szu-Wen Wang
Department of Chemical Engineering and Materials Science, The Henry Samueli School of Engineering, University of California, Irvine
Pyruvate dehydrogenase core protein (E2) from Bacillus stearothermophilus self assembles into a 25-nm nanocage structure with hollow core for possible entrapment of guest molecules. External architecture is hydrophilic, rendering it soluble in aqueous solution. Attachment of functional groups, such as antibody or binding ligands allows targeting while attachment of cross linkers allows formation of bigger complex. Internal architecture can be modified to accommodate guest molecules.
Poster presenter: Chengfei Lou, chengfel@uci.edu
Fabrication of Single-Biomolecule Electronic Devices
J. Mannik (1), B. R. Goldsmith (2), J. G. Coroneus (3), G. A. Weiss (4) and P. G. Collins (2)
1-Institute of Surface and Interface Science; 2-Department of Physics and Astronomy; 3-Department of Molecular Biology and Biochemistry; 4-Department of Chemistry, University of California, Irvine
New inventions in nanotechnology are likely to enable the investigation of biochemical reactions with single molecule precision. One promising approach is the integration of bioactive molecules into electronic devices. We present a two step method to build single protein sensors from carbon nanotube circuits. In the first, feedback-controlled step, a single attachment site is introduced to the nanotube sidewall using electrochemical oxidation. In the second step, the site is covalently linked to a protein's amide termination. The resulting circuits incorporate a single functional molecule and allow interrogation under various environments and biochemical conditions.
Poster presenter: Jaan Mannik, jmannik@uci.edu
Novel Biomaterials from Natural Building Blocks
Mark Metzke,1 Naphtali O’Connor,1 Jane Bai,1 Shelly Peyton,2 Andrew Putnam,2 and Zhibin Guan1,2*
1-Department of Chemistry; 2-Department of Biomedical Engineering, University of California, Irvine, CA 92697; *zguan@uci.edu
In the area of biomaterials research, our group focuses on the design of new and improved material systems derived from naturally abundant building blocks (carbohydrates and peptides). In using these starting materials we envision biomaterials with: i) rich functionality, making them ideal for further structural fine-tuning and allowing optimization of polymer systems, ii) inherent biocompatibility, being derived from biotic starting materials, iii) biodegradability, because the polymer chain is linked with enzymatically cleavable bonds (allowing the polymer to breakdown into benign materials), and iv) scalability, because of the simplicity with which the polymers are synthesized and the bulk availability of the starting materials. Thus far, two novel carbohydrate-derived side-chain polyethers were synthesized by condensation polymerization. Surface plasmon resonance spectroscopy studies demonstrated that these side-chain polyethers have exceptional resistance to protein binding, making them a promising biomaterial candidate. In addition, these polymers combine biodegradability and functionalizability, which give them high versatility and excellent potential for use as an extracellular matrices (ECM’s). These side-chain polyethers are currently undergoing in vitro cellular testing for tissue engineering applications through collaborations with colleagues in our biomedical engineering department. Additionally, a series of cationic carbohydrate-peptide copolymers was synthesized as a new class of biomaterials. Through collaboration with colleagues in the biophysics and physiology department, we found that our polymers allow gene transfection while maintaining excellent cell viability. These copolymers had almost no cytotoxicity in COS-7 cells or primary human cell lines (human aortic smooth muscle cells). Encouraged by these promising results, a whole family of carbohydrate-peptide copolymers is further proposed for biomaterial usage.
Poster presenter: Mark Metzke, mmetzke@uci.edu
Synthesis of spinel ferrite fine particles form aqueous solution at room temperature and their bio applications
K. Nishimura (1) and M. Inoue (2)
1-Department of Electrical and Electronic Engineering, Suzuka National College of Technology; 2-Department of Electrical and Electronic Engineering, Toyohashi University of Technology
Our method enables to synthesize MxFe3-xO4 (M = Cu, Zn, Fe, Ni, Co, Mn, and Mg) or MxZn~0.3Fe~2.7-xO4 ultra fine particles at room temperature, utilizing Fe2+ „_ Fe3+ oxidation by air (oxygen). This method has the industrial advantages (such as in open air and no heat equipment). A direct immobilization of biomolecules also enables onto their particles in this condition. Trypsin, a proteolytic enzyme or a protein, was immobilized onto the surfaces of ferrite (Fe3O4-Fe2O3 mixed solution) fine particles, ~ 8 nm in size, during the process in which the particles were synthesized from an aqueous solution.
Poster presenter: Kazuhiro Nishimura, kazuhiro24mura@nifty.com
Transparent conducting ZnO oxide film prepared by photochemical metal-organic deposition
Ho Jung Chang (1), Hyuncheol Kim (2), Chae-Seon Hong (2), and Hyung-Ho Park(2)*
1-Department of Electronic Engineering, Dankook University, Cheonan-shi, Chungnam 330-714, Korea; 2-Department of Ceramic Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-ku, Seoul, Korea
Transparent conducting oxides (TCOs) are widely used in high-, and low-tech applications such as antistatic coatings, touch display panels, solar cells, flat panel displays, and optical coating. In many TCO materials, zinc oxide (ZnO) has been receiving much attention in recent years due to its many technological applications. It has been used widely as transparent conducting electrodes, thin-film heaters, and gas sensors, etc. Furthermore it has drawn much interest as a potential TCO for applications in solar cells because of the advantages of non-toxicity, low cost, abundance, and stability in hydrogen plasma compared to indium tin oxide (ITO).
Poster presenter: Hyung-Ho Park, hhpark@yonsei.ac.kr
Thin film deposition and etching process, which brings some problems and demerits, by lithographic process using photoresist have to be repeated for obtaining a fine micro-scale patterning. However if we use photo-sensitive starting precursors and additives in thin film deposition, we do not need photoresist nor dry etching for micro-scale patterning. Furthermore because this is a solution technique, it is easily applicable to the deposition of complex oxide.
In this work, we prepared ZnO films by sol-gel spin-coating process. Direct-patterning of TCOs was carried out by using photosensitive stabilizer and UV exposure. Fourier transform infra-red spectroscopic observation showed that a complete removal of organic group was possibly obtained by UV exposure at room temperature. The phase formation and crystallinity of TCO films were monitored with x-ray diffractometer. The optical transmittance measurement was carried out using UV-visible spectrometer and the electrical properties such as sheet resistance, conductivity and hole effects were observed. Scanning electron microscopy was used to observe the image and the change in surface morphology of direct-patterned TCO films. This direct-patterning of TCO thin film formation process seems to be applicable to fabricate bio-related micro electro-mechanical system devices.
Quantitative analysis of CNS axon regeneration using microfluidic neuron culture device
Jeong Won, Behrad Vahidi, Madelyn Luttgen, and Noo Li Jeon
Department of Biomedical Engineering, University of California, Irvine
Progress in treatment of spinal cord injury is restricted due to limitations in in-vitro assays for testing pharmaceutical agents that may promote axonal regeneration. There are no available in-vitro methods to distinguish and assess regeneration of severed CNS axons. This work describes a microfluidics-based neuronal culture platform that overcomes the limitations described above.
Poster presenter: Jeong Won Park, parkjw@uci.edu
To develop a platform for screening potential drugs for spinal cord injury, we first tested the effect of various concentrations of NOGO-66 on length of regenerated axons. We cultured cortical neurons in the devices and subjected them to reproducible axotomy by vacuum aspiration. After 24 hours, the lengths of regenerated axons were measured for quantitative analysis. NOGO-66 concentrations above 10nM consistently resulted in ~20% reduction in length of regenerated axons.
Optimizing Platforms for Biological Probes
Jung Park (1), Ju H. Choi (1), Christof Strohhöfer (2), Regina Ragan (2)
1-Dept of Chemical Engineering and Materials Science, UC Irvine; 2-Fraunhofer IZM
Biological sensing devices based on surface enhanced Raman spectroscopy (SERS) of noble metal nanocrystals (NCs) are a promising avenue for use in gene arrays and proteomics. Metallic nanostructures have strong near field coupling between closely spaced particles, which offers the possibility of single molecule detection limits. We demonstrate a unique technique for fabricating ordered arrays of noble metal nanostructures of monodisperse size that can be integrated with polymer microsystems. The low cost integration of NC arrays on polymer substrates is achieved via self-assembly of metallic nanostructures and select attachment to diblock copolymer substrates.
Poster presenter: Jung Park, jungp@uci.edu
Effect of Low level Laser (LLL) on postnatal organotypic cultured rat utricles following gentamicin exposure
Yong-Won Chung, Chung-Ku Rhee, Phil-Sang Chung, Young Saeng Kim
Department of Otolaryngology-HNS, College of Medicine, Danook University
In normal postnatal mammalian inner-ear sensory epithelium, regeneration of inner ear hair cells is a very rare event, but they can regenerate with partial restoration of the vestibular sensory epithelium following ototoxic insult. The aim is to see the effect of LLL on hair-cell regeneration following gentamicin exposure on postnatal organotypic cultured rat utricle. Long-term organotypic culture of 2 to 7-day-old rat utricular maculae was obtained to study gentamicin-induced vestibular hair-cell renewal. In C-group, the utricle explants were cultured. In CL-group, cultured utricle explants were LLL irradiated. In G-group, the explants were exposed to gentamicin. In GL group, explants were LLL irradiated after exposure to gentamicin. The whole-mount utricles were stained with FM1-43, an efficient marker of live hair cells. The same FM1-43stained explants were cultured continuously and observed under confocal microscope at the scheduled dates. In C-group, utricle explant culture was maintained through 31 days. In CL-group, the utricle explant cells were multiplied. In G-group, regeneration peak was observed at day 18 after maximum damage at day 2. In GL group, the peak was seen at day 11 and it was sustained for 2 weeks. These results suggest that LLL promotes spontaneous hair cell regeneration following gentamicin damage in utricular explants.
Poster presenter: Chung-Ku Rhee, rheeck@dankook.ac.kr
Rapid isolation of adherent cells
Georgina Salazar, Yuli Wang, Phillip Aoto, Grace Young, Eric Stanbridge, Mark Bachman, Christopher Sims, G.P. Li, Nancy Allbritton.
Department of Biomedical Engineering, University of California, Irvine
We have developed a method for selecting and sorting adherent cells that is rapid and does not remove the cells from their growth surface. Current methods for sorting and isolating adherent cells are laborious or require surface detachment of the cells that can alter their physiology and morphology. Limiting dilution can require many weeks and may also involve application of a toxic antibiotic. Flow cytometry generally requires adherent cells to be trypsinized which removes surface markers as well as damages the plasma membrane. However, our method enables swift isolation of specific adherent cells without stressing cells. We microfabricated high density arrays of cell pallets, 50-100 microns in diameter. Cells attach and grow on the surfaces of the pallets that are fabricated from the polymer SU-8. Pallets can be individually removed from the array using a pulsed laser beam. The feasibility of isolating live, proliferating cells has been demonstrated. Thus, cells with desirable traits can be collected and clonally expanded yielding a population of cells with the desired properties, for example the presence of a surface protein. Biologists might use our technique to facilitate tasks such as isolating transfected cells, developing cell lines, and decoding random DNA or RNA libraries.
Poster presenter: Georgina Salazar, salazarg@uci.edu
Detection of Biomolecules Using an FET-Type Biosensor with a Built-in Quasi-Reference Electrode
Jang-Kyoo Shin (1), Dong-Sun Kim (1), Ho-Jin Choi (1) and Geunbae Lim (2)
1-Department of Electronics, Kyungpook National University, Daegu 702-701, Korea; 2-Department of Mechanical Eng., Pohang University of Science and Technology, Pohang 790-784, Korea
A field effect transistor (FET)-type biosensor with a built-in quasi-reference electrode for detecting DNA and protein molecules has been designed and fabricated using CMOS technology. Au and Pt were used as the gate metals of Bio-FET and reference FET (REFET), respectively, for selective detection of biomolecules. In order to compensate the interference due to noisy factors such as light, temperature and long term drift, both Bio-FET and REFET were used in a differential measurement circuit. A Pt built-in quasi-reference electrode was formed with the FET-type biosensor on the same Si substrate. Experimental results using thiol molecules showed that the proposed device could be used as a sensing component in the micro total analysis system (ìTAS) and lab-on-a chip.
Poster presenter: Jang-Kyoo Shin, jkshin@ee.knu.ac.kr
Highly sensitive magnetic field sensors using magnetoimpedance effect
Kwang-Ho Shin (1), Hironaga Uchida(1), Pang Boey Lim (1), Mitsuteru Inoue (1, 2)
1- Department of Electrical and Electronic Engineering, Toyohashi University of Technology; 2- CREST, Japan Science and Technology Corporation
In this study, we have investigated the optimization for design and applicability of the LC high pass filter configuration for the magnetoimpedance sensors, and examined its performance with simulation and experiment using amorphous magnetic pattern as a sensor element. Special attention is given to the sensitivity of the filter configuration. The LC filter circuit have shown the output changing ratio per 1 Oe of 5 % at 50 MHz. This value is larger in 2.5 times than the output changing ratio expected in a conventional bridge circuit with constant current excitation.
Poster presenter: Kwang-Ho Shin, khshin@eee.tut.ac.jp
MEMS-Based MHz Ultrasonic Nozzles and Applications
Y.L. Song (1), N. Wang (1), G. Qiu (1), S.C. Tsai (2), and C.S. Tsai (1)
1-Department of Electrical Engineering and Computer Science, University of California, Irvine; 2-Department of Chemical Engineering, California State University, Long Beach
This paper reports on ultrasonic atomization for production of monodisperse drops (mist). More than 93% of the drops 7.0 mm in diameter were produced using a MEMS-based 0.5 MHz 3-Fourier horn (FH) silicon nozzle 3.66 x 0.38 x 0.11 cm3 in size. The nozzle is made of a piezoelectric drive section and a silicon-resonator consisting of multiple FHs each with half wavelength in length and magnification of two in longitudinal vibration amplitude. As water exits from the 200mm x 200mm central channel of the nozzle, a liquid film is maintained at the nozzle tip that vibrates at the resonance frequency of 486.5 kHz and the drive voltage of 5.5 V, resulting in formation of standing capillary waves (SCW) on the free film surface. Temporal instability of these SCW sets in as the tip vibration amplitude exceeds a threshold, and a spray of drops is produced. The resonance effect of the multiple FHs facilitates the breakup of SCW at the single frequency, and monodisperse drops are produced as a result.
Poster presenter: Y.L. Song, cstsai@uci.edu
Some of the potential applications of such nozzles are: (1) spray pyrolysis for nanoparticles synthesis, (2) 3-D spray coating of bio- or nano-dispersions, and (3) use in pocket-size nebulizers for alveolar delivery of medicines.
Polarization dependent OCT imaging of biological tissue
Jianping Su (1), I. V. Tomov(2), Zhongping Chen (1)
1-Department of Biomedical Engineering; 2-Beckman Laser Institute,University of California, Irvine, California, USA
We used continuum generated in 8.5 cm long fiber by femtosecond Yb fiber laser to improve the axial resolution of frequency domain SH-OCT to12 m. The acquisition time is shorten by more than two orders of magnitude compared to TD SH OCT. The system was applied to image biological tissue of fish scales, pig leg tendon and rabbit eye sclera. Highly organized collagen fibrils can be visualized in the recorded images. Polarization dependence on second harmonic has been used to obtain polarization resolved images.
Poster presenter: Jianping Su, jianpis@uci.edu
Integrated Smart Micro Sensors with Short-Distance RF-Communication Unit for Life-Related Sensing Applications
H.Takao, J.W.Kim, T.Noda, M.Sudou, K.Sawada, and M.Ishida
Toyohashi University of Technology
In this study, device technologies of wireless smart micro sensors for human\'s life related sensing applications have been investigated. The goal of the study is realization of monolithically integrated smart micro devices with various kinds of sensors, their signal processor, and RF-unit for short-distance data communication, which realizes small size and very light weight wireless sensing devices. The effect of total integration in a microchip configuration is very essential for the application, since it will reduce invasion or stress to the examinees caused by the wearable devices. Basic concept, elemental and essential technologies, and novel sensor technologies for life-related sensing applications are introduced.
Poster presenter: Hidekuni Takao, takao@eee.tut.ac.jp
Controlled Drug Delivery System
Han-Kuan Tsai (1), Han Xu (2), Chunlei Wang (2), Lawrence Kulinsky, (2) Marc Madou (2)
1-Department of Material Science and Engineering 2- Department of Mechanical Engineering, University of California, Irvine
A bi-layer structure comprising a thin metal layer and a polypyrrole (PPy) film is developed as a valve. In such a structure, the thin metal layer functions as a working electrode, and the polypyrrole (PPy) film is electrochemically deposited on the metal electrode as an actuator. The actuation mechanism of the valve is based on ions¡¦ movement in and out of the polypyrrole film upon reduction and oxidation reaction. A method proposed to increase the drug release system¡¦s functionality by the inclusion of a protective cap that serves dual roles- a drug reservoir and an integrated enclose to ensure reliable operation of the drug release flap unencumbered by the surrounding tissues. The release test platform with a channel and two reservoirs is fabricated on a PMMA chip to test the efficiency of the valve operation. This technology demonstrates that the novel integration is capable of enhancing a functional drug delivery device.
Poster presenter: Han-Kuan Tsai, tsaih@uci.edu
Dielectrophoresis switching in microfluidics
Lisen Wang (1), Danny Kuo (1), Steve Marchenko (2), Lisa Flanagan (2), Edwin Monuki (2), Abraham P Lee (1,3)
1-Department of Biomedical Engineering; 2-Department of Pathology; 3-Department of Mechanical Engineering, University of California, Irvine
We present the design and test of dielectrophoresis (DEP) switching in microfluidics. Vertical electrodes at the side wall of microchannel are fabricated and configured to generate non-uniform electric field and correspondingly DEP force along the lateral direction of microchanel. The beads/ cells can be positioned at any location and automatically flow into the downstream channel outlets. The switching design is validated by experiment from polystyrene microbeads. The switching can be expanded to multiple channel outputs and the DEP positioning zone can be optimized to achieve higher throughput sorting than current DEP devices.
Poster presenter: Lisen Wang, lisenw@uci.edu
Micromachined Varying-Length Electrode Arrays for Auditory Neural Prostheses
Jian Wu, William Tang
Department of Electrical Engineering and Computer Science, University of California, Irvine
This paper presents the design, fabrication and characterization of a novel high-density varying-length microelectrode array for auditory neural prostheses. Direct stimulation of the auditory nerve offers significant advantages over cochlear implants by providing increased spectral resolution and lower power consumption. These state-of-the-art researches reported electrode arrays have a shank-to-shank distance of at least 400 µm, which is too large for implantation in the 1.5 mm diameter of the auditory nerve near the cochlea. We fabricated a 100-channel silicon microelectrode array in an area of 1 mm2 with different lengths from 0.75 mm to 0.2 mm using bulk micro machining. This design could provide access to most fascicles within the auditory nerve and provide graded control of multiple individual muscles and acquisition of a large amount of sensory information from peripheral mechanoreceptors.
Poster presenter: Jian Wu, jianw@uci.edu
Droplet Screens in Nanovolumes Using Static Conditions
L. Wu (1), W. Xu (2), M. Bachman (2), and G.P. Li (1, 2)
1-Department of Interdisciplinary Material Science and Engineering, University of California, Irvine; 2-Department of Electrical Engineering and Computer Science, University of California, Irvine
Microfluidic droplet systems have shown great promise in high throughput chemical assays to minimize chemical consumption and increase process efficiency. We report a droplet system that forms nanovolume drops under static conditions. The programmability of drop sizes is determined by geometric configurations and surface tension, and not particularly sensitive to flow rates. The geometry of the device predetermines locations of drops, and thus it is easy to identify the locations of drops and the volumes of the drops within them. Further integration can be made to generate screening assays and utilized in various applications such as crystallization screening and solubility studies. This technology makes hand-operated systems a possibility, since precision control of flow rates is not necessary.
Poster presenter: Liang Wu, lwu@uci.edu
Virtual Wall and Its Applications in Microfluidics
Wei Xu, Mark Bachman, G.P.Li
Department of Electrical Engineering and computer Science, University of California, Irvine
Surface properties is the most important factor in microfluidic research, which is the basis for life chip. This poster is prensenting a virtual wall technique to modifiy surface condition and based on this technique, microvalve, micropump, micromixer,microflowregulator and microdroplets generation chip are designed with advantages of low cost, low power and easy fabrication.
Poster presenter: Wei Xu, wxu@uci.edu
Programmable droplets in microfluidic devices
V. Yeh (1), G.P. Li (1), M. Bachman (1)
1-Department of Electrical Engineering and Computer Science, University of California, Irvine
A programmable droplet generator is an important and highly sought-after component for many microfluidic systems. By producing controlled droplets of variable size on demand, a myriad of potential applications are made possible. Our proposed device produces programmable drops by physically breaking flows of water at precise points. Using computer-controlled solenoid valves, a reasonably high throughput level should be obtainable, resulting in a highly programmable, precise droplet generation device with a substantial throughput.
Poster presenter: Victor Yeh, vsyeh@uci.edu
Optimization of micromixers using computational fluid dynamics and micro genetic algorithm
W. Yoo (1), Y.-M. Kim (1), W.-S. Kim (2), I.-T. Im (3), K.S. Kim (4)
1-Department of Mechanical Engineering, Graduate School, Hanyang University; 2-Department of Mechanical Engineering, Hanyang University; 3-Department of Automotive Engineering, Iksan National College; 4-Department of Mechatronics, Korea University of Education and Technology
Mixing of different fluids in microchannel is inevitable to develop bio-MEMS or a “lap on a chip” devices. Passive micromixer has been attractive to the bio-MEMS engineers since no external power is necessary for mixing. In this study, the shape of a passive micromixer has been optimized using coupled computational fluid dynamics and micro genetic algorithm.
Poster presenter: W. Yoo, itim@iksan.ac.kr
Y type passive micromixer was chosen and triangular-shaped mixing elements have been placed to improve the mixing in the micromixer. High mixing efficiency always results in large pressure drop, which is able to cause failure of the micropump. It is possible to get the maximum mixing efficiency and the minimum pressure drop if the shape of the channel design were optimized.
The optimization program was composed of three modules. The fluid flow in the channel was solved using computational fluid dynamics in the analysis module and resulting field variables were handed over to the optimization module by the control module. Mixing length defined by the concentration distribution and Reynolds number for various geometrical shapes were examined to obtain the optimal shape.
Compared to the base model, the mixing efficiency of optimized model was high up to 39.4% and the pressure drop was lowered to 9.14%. The pareto optimal solutions were also found to show the relations between mixing efficiency and pressure drop.
Parallel Arrays of Monodisperse Platinum Nanowires and Nanocrystals on Si(001) via a Self-Assembled Template
Jiun Pyng You (1), Sehun Kim (2), Xuema Li (3), R. Stanley Williams (3) and Regina Ragan (1)
1-Department of Chemical Engineering and Materials Science, University of California, Irvine; 2-Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1 Geseong-dong, Yuseong-gu, Daejeon, 305-701, Korea; 3-Quantum Science Research Group, Hewlett-Packard Laboratories, MS 1123, 1501 Page Mill Rd, Palo Alto, CA 94304, USA
We have developed a process for fabricating monodisperse noble metal nanocrystals and nanowires in ordered arrays on Si(001) with feature size of 3-10 nm, with achievable density of 1011 / cm2, and over areas >1 µm2. Unidirectional, self-assembled rare earth disilicide nanowires were used as a template for Pt nanostructure arrays. Scanning electron microscopy images demonstrate the ability to select nanowires or nanocrystals as a function of Pt coverage. Statistical analysis of images of Pt nanocrystal arrays yield a mean feature size of 3.6 nm and a size distribution of ±1.8 nm around the mean.
Poster presenter: Jiun-Pyng You, jpyou@uci.edu
Nanoparticle induced ablation for cancer therapy
K. Zanjani (1), M. Bachman (1), R. Holcombe (2), G.P. Li (1)
1-Department of Electrical Engineering and Computer Science, University of California, Irvine, CA, USA 2-UCI Medical Center, University of California, Irvine, Orange, CA, USA
Biocompatible magnetic materials have found various uses, and in particular their use is being investigated as a therapeutic in cancer therapy. At the nanoscale, biocompatible iron oxide nanoparticles respond to radio frequency energy ("AC magnetic fields") and release heat as a result of rapid changes in magnetic orientation. The heat that is generated is considered to be therapeutic in the area of targetted cancer therapy known as "hyperthermia". Hyperthermia seeks to locally raise the temperature in different regions of tissue in order to cause the denaturing of cancer cells, typically at elevated temperatures near 42 ~ 45 degrees Celsius.
Poster presenter: Kevin Zanjani, kzanjani@uci.edu
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