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Microfabrication Technologies (microfabrication + technology)

Distribution by Scientific Domains

Life Sciences	80%

Selected Abstracts

Recent advances in microdevices for electrochemical energy conversion and storage

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 6-7 2007
Gerardo Jose La O'
Abstract The application of silicon microfabrication technologies to electrochemical devices allows reduction of overall device package to potentially increase volumetric power densities. This review first focuses on some exciting developments in microfuel cells, in particular, solid oxide fuel cells (SOFCs) and proton exchange membrane fuel cells (PEMFCs). The emphasis is given to innovative 2D processing methods, novel 2D architectures of microfuel cells, and demonstrated performance in terms of area power densities. Emerging 3D fabrication techniques that are potentially promising to produce 3D electrochemical devices such as 3D cell and stack architectures on the micrometer scale will then be discussed. Lastly this paper highlights some new opportunities in electrode kinetics studies enabled by microfabricated devices,investigation of scaling relationship between microelectrodes and electrochemical responses, which has led to improved fundamental understanding of electrode reactions and rate-limiting steps. Copyright © 2007 John Wiley & Sons, Ltd. [source]

In this issue: Biotechnology Journal 11/2009

BIOTECHNOLOGY JOURNAL, Issue 11 2009
Article first published online: 13 NOV 200
Forensic identification on chips Choi and Seo et al., Biotechnol. J. 2009, 4, 1530,1541 Short tandem repeat (STR) analysis can be used for genetic fingerprinting of individuals as it is done for forensic human identification. However, the current state-of-the-art STR genotyping processes and instruments are labor intensive, expensive, time consuming, and lack portability. Micro-total-analysis systems or lab-on-a-chip platforms based on microfabrication technologies have the capability to miniaturize and integrate bioanalysis steps in a single format and have already been successfully applied for forensic STR typing. Researchers from Daejeon, Korea, highlight up-to-date work on advanced microdevices for high-throughput STR genotyping, and a portable integrated microsystem for on-site forensic DNA analysis. Surface plasmon resonance on chips Maynard et al., Biotechnol. J. 2009, 4, 1542,1558 Technologies based on surface plasmon resonance (SPR) have allowed rapid, label-free characterization of protein-protein and protein-small molecule interactions. SPR has become the gold standard in industrial and academic settings, in which the interaction between a pair of soluble binding partners is characterized in detail or a library of molecules is screened for binding against a single soluble protein. In spite of these successes, SPR is only beginning to be adapted to the needs of membrane-bound proteins which are promising targets for drug and biomarker development. This team of authors from Austin, Minneapolis and Rochester (all USA) describe current SPR instrumentation and the potential for SPR nanopore arrays to enable quantitative, high-throughput screening of G-protein coupled receptor ligands and applications in cellular biology. Nucleotide immobilization on chips Sethi et al., Biotechnol. J. 2009, 4, 1513,1529 The development of oligonucleotide-based microarrays (biochips) is of major interest in science and biotechnology industry and has applications in a wide range of research areas including genomics, proteomics, computational biology and pharmaceuticals. Especially microarrays have proven to be a unique method for time and cost efficient analysis of thousands of genes at one. Authors from Delhi and Lucknow, India discuss currently used chemical strategies for immobilization of oligonucleotides and put a special emphasis on post-synthetic immobilization on glass surfaces. Recent advances on these synthesis pathways are presented in detail. [source]

An integrated microdevice for high-performance short tandem repeat genotyping

BIOTECHNOLOGY JOURNAL, Issue 11 2009
Jong Young Choi
Abstract Short tandem repeat (STR) analysis provides genetic fingerprinting of individuals, and is considered as a powerful and indispensable technique for forensic human identification. However, the current state-of-the-art STR genotyping processes and instruments are labor intensive, expensive, time consuming, and lack portability. Micro-total-analysis systems or lab-on-a-chip platforms based on microfabrication technologies have the capability to miniaturize and integrate bioanalysis steps in a single format. Recent progress in microsystems has demonstrated their successful performance for the forensic STR typing with a reduced cost, high speed, and improved high throughput. The purpose of this review article is to highlight up-to-date work on advanced microdevices for high-throughput STR genotyping, and a portable integrated microsystem for on-site forensic DNA analysis. [source]

Effects of substrate geometry on growth cone behavior and axon branching

DEVELOPMENTAL NEUROBIOLOGY, Issue 11 2006
Ginger S. Withers
Abstract At the leading edge of a growing axon, the growth cone determines the path the axon takes and also plays a role in the formation of branches, decisions that are regulated by a complex array of chemical signals. Here, we used microfabrication technology to determine whether differences in substrate geometry, independent of changes in substrate chemistry, can modulate growth cone motility and branching, by patterning a polylysine grid of narrow (2 or 5 ,m wide) intersecting lines. The shape of the intersections varied from circular nodes 15 ,m in diameter to simple crossed lines (nodeless intersections). Time-lapse recordings of cultured hippocampal neurons showed that simple variations in substrate geometry changed growth cone shape, and altered the rate of growth and the probability of branching. When crossing onto a node intersection the growth cone paused, often for hours, and microtubules appeared to defasciculate. Once beyond the node, filopodia and lamellipodia persisted at that site, sometimes forming a collateral branch. At nodeless intersections, the growth cone passed through with minimal hesitation, often becoming divided into separate areas of motility that led to the growth of separate branches. When several lines intersected at a common point, growth cones sometimes split into several subdivisions, resulting in the emergence of as many as five branches. Such experiments revealed an intrinsic preference for branches to form at angles less than 90°. These data show that simple changes in the geometry of a chemically homogeneous substrate are detected by the growth cone and can regulate axonal growth and the formation of branches. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 1183,1194, 2006 [source]

Low-voltage electroosmosis pump for stand-alone microfluidics devices

ELECTROPHORESIS, Issue 1-2 2003
Yuzuru Takamura
Abstract Two types of low-voltage electroosmosis pumps were developed using microfabrication technology for usage in handy or stand-alone applications of the micrototal analysis systems (,-TAS) and the lab-on-a-chip. This was done by making a thin (<,1 ,m) region in the flow path and by only applying voltages near this thin region using electrodes inserted into the flow path. The inserted electrodes must be free from bubble formation and be gas-tight in order to avoid pressure leakage. For these electrodes, Ag/AgCl or a gel salt bridge was used. For patterning the gel on the chip, a hydrophilic photopolymerization gel and a photolithographic technique were optimized for producing a gel with higher electric conductivity and higher mechanical strength. For high flow rate application, wide (33.2 mm) and thin (400 nm) pumping channels were compacted into a 1 mm×6 mm area by folding. This pump achieves an 800 Pa static pressure and a flow of 415 nL/min at 10 V. For high-pressure application, a pump was designed with the thin and thick regions in series and positive and negative electrodes were inserted between them alternatively. This pump could increase the pumping pressure without increasing the supply voltage. A pump with 10-stage connections generated a pressure of 25 kPa at 10 V. [source]