A micropunching lithography approach is developed to generate micro- and submicron-patterns on top, sidewall and bottom surfaces of polymer substrates. It overcomes the obstacles of patterning conducting polymers and generating sidewall patterns. This method allows rapid fabrication of multiple features and is free of aggressive chemistry.
1Department of Bioengineering, University of Washington, 2Department of Pathology, University of Washington
In this protocol, we demonstrate the fabrication of biomimetic cardiac cell culture substrata made from two distinct polymeric materials using capillary force lithography. The described methods provide a scalable, cost-effective technique to engineer the structure and function of macroscopic cardiac tissues for in vitro and in vivo applications.
A versatile plasma lithography technique has been developed to generate stable surface patterns for guiding cellular attachment. This technique can be applied to create cell networks including those that mimic natural tissues and has been used for studying several, distinct cell types.
Published June 14, 2011. Keywords: Bioengineering, Cell Network, Surface Patterning, Self-Organization, Developmental Biology, Tissue Engineering, Nanopattern, Micropattern, Self-Assembly, Cell Guidance, Neuron
Surface Enhanced Raman Spectroscopy Detection of Biomolecules Using EBL Fabricated Nanostructured Substrates
1Department of Electrical and Computer Engineering, University of Alberta, 2National Institute for Nanotechnology, National Research Council of Canada
We describe the fabrication and characterization of nano-biological systems interfacing nanostructured substrates with immobilized proteins and aptamers. The relevant experimental steps involving lithographic fabrication of nanostructured substrates, bio-functionalization, and surface-enhanced Raman spectroscopy (SERS) characterization, are reported. SERS detection of surface-immobilized proteins, and probing of protein-ligand and aptamer-ligand binding is demonstrated. …
Published March 20, 2015. Keywords: Engineering, Bio-functionalized surfaces, proteins, aptamers, molecular recognition, nanostructures, electron beam lithography, surface-enhanced Raman spectroscopy.
1Laboratoire Interdisciplinaire Carnot de Bourgogne CNRS-UMR 6303, Université de Bourgogne, 2Department of Optics and Optical Engineering, University of Science and Technology of China, 3CEMES, CNRS-UPR 8011
Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.
Published December 11, 2013. Keywords: Physics, light transmission, optical waveguides, photonics, plasma oscillations, plasma waves, electron motion in conductors, nanofabrication, Information Transport, plasmonics, Silver Nanowires, Leakage radiation microscopy, Electromigration
A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.
Published April 4, 2013. Keywords: Bioengineering, Microbiology, Cellular Biology, Biochemistry, Molecular Biology, Biophysics, Cell migration, live cell imaging, soluble and adherent gradients, microcontact printing, dip pen lithography, microfluidics, RGD, PEG, biotin, streptavidin, chemotaxis, chemoattractant, imaging
Microfluidic Picoliter Bioreactor for Microbial Single-cell Analysis: Fabrication, System Setup, and Operation
1Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Juelich GmbH
In this protocol the fabrication, setup and basic operation of a microfluidic picoliter bioreactor (PLBR) for single-cell analysis of prokaryotic microorganisms is introduced. Industrially relevant microorganisms were analyzed as proof of principle allowing insights into growth rate, morphology, and phenotypic heterogeneity over certain time periods, hardly possible with conventional methods.…
Published December 6, 2013. Keywords: Bioengineering, Soft lithography, SU-8 lithography, Picoliter bioreactor, Single-cell analysis, Polydimethylsiloxane, Corynebacterium glutamicum, Escherichia coli, Microfluidics, Lab-on-a-chip
1Department of Electrical and Computer Engineering, The University of Utah, 2Department of Chemistry, The University of Wisconsin-Madison
We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.…
Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering (cavities).…
Published November 30, 2012. Keywords: Physics, Optics and Photonics, Astronomy, light scattering, light transmission, optical waveguides, photonics, photonic crystals, Slow-light, Cavities, Waveguides, Silicon, SOI, Fabrication, Characterization
Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, 2School of Medicine, University of California, San Francisco, 3Department of Radiology and Biomedical Imaging, UCSF Medical Center, 4University of California, San Francisco, 5Hansen Medical, Mountain View, CA
Current applied to an endovascular microcatheter with microcoil tip made by laser lathe lithography can achieve controllable deflections under magnetic resonance (MR) guidance, which may improve speed and efficacy of navigation of vasculature during various endovascular procedures.
Published April 4, 2013. Keywords: Biomedical Engineering, Medicine, Bioengineering, Molecular Biology, Anatomy, Physiology, Surgery, Delivery of Health Care, Health Services Research, catheter, microcatheter, deflection, navigation, interventional, Magnetic Resonance Imaging, MRI, lithography, imaging, vascular, endovascular procedures, clinical techniques
1Department of Physics, University of Pittsburgh
Oxide nanostructures provide new opportunities for science and technology. The interfacial conductivity between LaAlO3 and SrTiO3 can be controlled with near-atomic precision using a conductive atomic force microscopy technique. The protocol for creating and measuring conductive nanostructures at LaAlO3/SrTiO3 interfaces is demonstrated.…
Published July 18, 2014. Keywords: Physics, oxide nanostructures; nanoelectronics; semiconductor; LaAlO3/SrTiO3; lithography; AFM nanolithography
The fabrication of electrically addressable, high-aspect-ratio (> 1000:1) metal nanowires separated by gaps of single nanometers using either sacrificial layers of aluminum and silver or self-assembled monolayers as templates is described. These nanogap structures are fabricated without a clean room or any photo- or electron-beam lithographic processes by a form of edge lithography known as nanoskiving.…
Published May 13, 2013. Keywords: Chemistry, Materials Science, Chemical Engineering, Electrical Engineering, Physics, Nanotechnology, nanodevices (electronic), Nanoskiving, nanogaps, nanofabrication, molecular electronics, nanowires, fabrication, etching, ultramicrotome, scanning electron microscopy, SEM
1School of Electrical Engineering & Telecommunications, University of New South Wales, 2QCD Labs, COMP Centre of Excellence, Department of Applied Physics, Aalto University
The fabrication process and experimental characterization techniques relevant to single-electron pumps based on silicon metal-oxide-semiconductor quantum dots are discussed.
Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting
1Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), 2Department of Electrical Engineering and Computer Sciences, University of California, Berkeley
We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes.
Published January 23, 2013. Keywords: Materials Science, Nanotechnology, Mechanical Engineering, Electrical Engineering, Computer Sciences, Physics, dielectrics (electronic application), light emitting diodes (LED), lithography (circuit fabrication), nanodevices (electronic), optoelectronics (applications), photoelectric devices, semiconductor devices, solar cells (electrical design), Surface patterning, nanoimprinting, nanomoulding, transfer moulding, functional materials, transparent conductive oxides, microengineering, photovoltaics
1Chemical and Biomolecular Engineering Department, Johns Hopkins University
A procedure for creating and imaging capillary bridges in slit-pore geometry is presented. The creation of capillary bridges relies on the formation of pillars to provide a directional physical and chemical heterogeneity to pin the fluid. Capillary bridges are formed and manipulated using microstages and visualized using a CCD camera.
Published January 9, 2014. Keywords: Physics, Microfluidics, Surface Properties, Capillary Action, Surface Tension, fluid forces, fluidics, polydimethylsiloxane molding, self-assembled monolayers, surface patterning, imprint transfer lithography, surface tension, capillarity, wetting
1Bredesen Center, University of Tennessee, Knoxville, 2Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 3Department of Materials Science and Engineering, University of Tennessee, Knoxville
A microfabricated device with sealable femtoliter-volume reaction chambers is described. This report includes a protocol for sealing cell-free protein synthesis reactants inside these chambers for the purpose of understanding the role of crowding and confinement in gene expression.
We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.
Published February 4, 2013. Keywords: Chemistry, Chemical Engineering, Biomolecular Engineering, Materials Science, Physics, Nanotechnology, Molecular Self-assembly, Electrochemistry, Folding, three dimensional, lithography, colloid, patchy particles, particles, nanoparticles, robotics, drug delivery, microfabrication, nanofabrication, nano, assembly, synthesis, reaction, origami
1Department of Physics, The State University of New York at Buffalo, 2Joint Quantum Institute, University of Maryland, 3The National Institute of Standards and Technology, 4Cryogenics and Fluids Branch, NASA Goddard Space Flight Center, 5HRL Laboratories
A method for permanently bonding two silicon wafers so as to realize a uniform enclosure is described. This includes wafer preparation, cleaning, RT bonding, and annealing processes. The resulting bonded wafers (cells) have uniformity of enclosure ~1%1,2. The resulting geometry allows for measurements of confined liquids and gasses.
Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters
We describe methods for the design, fabrication, and experimental characterization of plasmonic photoconductive emitters, which offer two orders of magnitude higher terahertz power levels compared to conventional photoconductive emitters.
Published July 8, 2013. Keywords: Physics, Electrical Engineering, Computer Science, Materials Science, Electronics and Electrical Engineering, Instrumentation and Photography, Lasers and Masers, Optics, Solid-State Physics, Terahertz, Plasmonic, Time-Domain Spectroscopy, Photoconductive Emitter, electronics
Procedure for the Development of Multi-depth Circular Cross-sectional Endothelialized Microchannels-on-a-chip
1Lane Department of Computer Science and Electrical Engineering, West Virginia University, 2Department of Cell Biology and Neuroscience, University of California at Riverside
A microchannels-on-a-chip platform was developed by the combination of photolithographic reflowable photoresist technique, soft lithography, and microfluidics. The endothelialized microchannels platform mimics the three-dimensional (3D) geometry of in vivo microvessels, runs under controlled continuous perfusion flow, allows for high-quality and real-time imaging and can be applied for microvascular research.…
Published October 21, 2013. Keywords: Bioengineering, Bioengineering, Tissue Engineering, Miniaturization, Microtechnology, Microfluidics, Reflow photoresist, PDMS, Perfusion flow, Primary endothelial cells
1Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
In this article we present a microfluidic chip for single cell analysis. It allows the quantification of intracellular proteins, enzymes, cofactors, and second messengers by means of fluorescent assays or immunoassays.
A simple microfluidic device has been developed to perform anesthetic free in vivo imaging of C. elegans, intact Drosophila larvae and zebrafish larvae. The device utilizes a deformable PDMS membrane to immobilize these model organisms in order to perform time lapse imaging of numerous processes such as heart beat, cell division and sub-cellular neuronal transport. We demonstrate the use of this device and show examples of different types of data collected from different model systems.…
Published September 30, 2012. Keywords: Bioengineering, Molecular Biology, Neuroscience, Microfluidics, C. elegans, Drosophila larvae, zebrafish larvae, anesthetic, pre-synaptic vesicle transport, dendritic transport of glutamate receptors, mitochondrial transport, synaptotagmin transport, heartbeat
Fabrication, Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics
1NEST Center for Nanotechnology Innovation, Istituto Italiano di Tecnologia, 2NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR
In this video we first describe fabrication and operation procedures of a surface acoustic wave (SAW) acoustic counterflow device. We then demonstrate an experimental setup that allows for both qualitative flow visualization and quantitative analysis of complex flows within the SAW pumping device.
Published August 27, 2013. Keywords: Physics, Microfluidics, Acoustics, Engineering, flow characteristics, flow measurement, flow visualization (general applications), fluidics, surface acoustic wave, flow visualization, acoustofluidics, MEMS, STICS, PIV, microfabrication, acoustics, particle dynamics, fluids, flow, imaging, visualization
Evaluation of Cancer Stem Cell Migration Using Compartmentalizing Microfluidic Devices and Live Cell Imaging
1Department of Biomedical Engineering, University of Wisconsin-Madison, 2Materials Science Program, University of Wisconsin-Madison, 3Department of Neurological Surgery, University of Wisconsin-Madison, 4Carbone Comprehensive Cancer Center and Center for Stem Cell and Regenerative Medicine, University of Wisconsin-Madison
A compartmentalizing microfluidic device for investigating cancer stem cell migration is described. This novel platform creates a viable cellular microenvironment and enables microscopic visualization of live cell locomotion. Highly motile cancer cells are isolated to study molecular mechanisms of aggressive infiltration, potentially leading to more effective future therapies.…
1Department of Chemistry and Applied Biosciences, ETH Zurich
We present a discrete droplet sample introduction system for inductively coupled plasma mass spectrometry (ICPMS). It is based on a cheap and disposable microfluidic chip that generates highly monodisperse droplets in a size range of 40−60 µm at frequencies from 90 to 7,000 Hz.
Published March 5, 2015. Keywords: Bioengineering, mass spectrometry, ICPMS, microfluidics, droplet microfluidics, monodisperse, sample introduction, chip, red blood cells, erythrocytes, single cell analysis
Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators
1Department of Electrical and Computer Engineering, University of California, Davis, 2Digital Light Projection (DLP) Technology Development, Texas Instruments, 3Birck Nanotechnology Center and the Department of Electrical and Computer Engineering, Purdue University
The robust device design of fringing-field electrostatic MEMS actuators results in inherently low squeeze-film damping conditions and long settling times when performing switching operations using conventional step biasing. Real-time switching time improvement with DC-dynamic waveforms reduces the settling time of fringing-field MEMS actuators when transitioning between up-to-down and down-to-up states.…
1Materials Science and Technology Division, Oak Ridge National Laboratory, 2Department of Physics & Astronomy, University of Tennessee, Knoxville
We describe the use of pulsed laser deposition (PLD), photolithography and wire-bonding techniques to create micrometer scale complex oxides devices. The PLD is utilized to grow epitaxial thin films. Photolithography and wire-bonding techniques are introduced to create practical devices for measurement purposes.
Published July 1, 2013. Keywords: Materials Science, Physics, Chemistry, Chemical Engineering, Mechanical Engineering, Nanotechnology, electrical transport properties in solids, condensed matter physics, thin films (theory, deposition and growth), conductivity (solid state), Pulsed laser deposition, oxides thin films, photolithography, wire-bonding, thin film, etching, fabrication, nanofabrication
Fabricating Complex Culture Substrates Using Robotic Microcontact Printing (R-µCP) and Sequential Nucleophilic Substitution
1Department of Biomedical Engineering, University of Wisconsin, Madison, 2Department of Mechanical Engineering, University of Wisconsin, Madison
Cell culture substrates functionalized with microscale patterns of biological ligands have immense utility in the field of tissue engineering. Here, we demonstrate the versatile and automated manufacture of tissue culture substrates with multiple, micropatterned poly(ethylene glycol) brushes presenting orthogonal chemistries that enable spatially precise and site-specific immobilization of biological ligands. …
1Biomedical Technology, CFD Research Corporation
Flow chambers used in adhesion experiments typically consist of linear flow paths and require multiple experiments at different flow rates to generate a shear adhesion map. SynVivo-SMN enables the generation of shear adhesion map using a single experiment utilizing microliter volumes resulting in significant savings in time and consumables.
Printing Thermoresponsive Reverse Molds for the Creation of Patterned Two-component Hydrogels for 3D Cell Culture
1Department of Health Science & Technology, Cartilage Engineering & Regeneration, 2Biomaterials Department, Innovent e.V.
A bioprinter was used to create patterned hydrogels based on a sacrificial mold. The poloxamer mold was backfilled with a second hydrogel and then eluted, leaving voids which were filled with a third hydrogel. This method uses fast elution and good printability of poloxamer to generate complex architectures from biopolymers.
Published July 10, 2013. Keywords: Bioengineering, Immunology, Cellular Biology, Biomedical Engineering, Biophysics, Molecular Biology, Materials Science, Tissue Engineering, Biomaterials, Hydrogel, Biopolymers, Structured/Patterned Hydrogels, Bioprinter, Sacrificial Mold, Thermoresponsive Polymers, Poloxamer, tissue, polymer, matrix, cell, cell culture
1Department of Integrative Biology and Physiology, University of California, Los Angeles, 2Department of Aerospace and Mechanical Engineering, University of Notre Dame, 3Molecular Imaging Center, University of Southern California
We demonstrate a microfluidics-based assay to measure the timescale for cells to transit through a sequence of micron-scale constrictions.
We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.…
1Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, 2Materials Science, Zernike Institute for Advanced Materials, University of Groningen, 3ICTM - Center for Catalysis and Chemical Engineering
This article describes the preparation of well-ordered nickel nanofoams via electroless metal deposition onto nanoporous templates obtained from self-assembled diblock copolymer based supramolecules.
Published April 28, 2014. Keywords: Chemistry, polymers, polymer matrix composites, foam materials, block copolymers, self-assembly, supramolecules, gyroid, nanoporous, electroless plating, metal nanofoams
In this article, we present a microfluidic-based method for particle confinement based on hydrodynamic flow. We demonstrate stable particle trapping at a fluid stagnation point using a feedback control mechanism, thereby enabling confinement and micromanipulation of arbitrary particles in an integrated microdevice.
Here we describe a simple method for patterning oxide-free silicon and germanium with reactive organic monolayers and demonstrate functionalization of the patterned substrates with small molecules and proteins. The approach completely protects surfaces from chemical oxidation, provides precise control over feature morphology, and provides ready access to chemically discriminated patterns.…
In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.
We demonstrate fabrication of a simple microfluidic device that can be integrated with standard electrophysiology setups to expose microscale surfaces of a brain slice in a well controlled manner to different neurotransmitters.
We present a simple method to produce microfluidic devices capable of applying similar dynamic conditions to multiple distinct strains, without the need for a clean room or soft lithography.
We present a procedure for forming a poly(ethylene glycol) self-assembled monolayer (PEG-SAM) on a silicon substrate with gold microelectrodes. The PEG-SAM is formed in a single step and prevents biofouling on silicon and gold surfaces. Electrophoresis is then used for patterning biomolecules down to the nanoscale.
1Center for Bio/Molecular Science & Engineering, US Naval Research Laboratory, 2Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill
Two adjacent fluids passing through a grooved microfluidic channel can be directed to form a sheath around a prepolymer core; thereby determining both shape and cross-section. Photoinitiated polymerization, such as thiol click chemistry, is well suited for rapidly solidifying the core fluid into a microfiber with predetermined size and shape.
1Department of Electrical and Computer Engineering, University of Minnesota, 2Department of Biomedical Engineering, University of Minnesota, 3Department of Neurology, Mayo Clinic College of Medicine, 4Department of Immunology, Mayo Clinic College of Medicine
Supported lipid bilayers and natural membrane particles are convenient systems that can approximate the properties of cell membranes and be incorporated in a variety of analytical strategies. Here we demonstrate a method for preparing microarrays composed of supported lipid bilayer-coated SiO2 beads, phospholipid vesicles or natural membrane particles.
Micro-particle image velocimetry (μPIV) is used to visualize paired images of micro particles seeded in blood flows which are cross-correlated to give an accurate velocity profile. Shear rate, maximum velocity, velocity profile shape, and flow rate, each of which has clinical applications, can be derived from these measurements.
Published April 25, 2013. Keywords: Bioengineering, Biophysics, Chemical Engineering, Mechanical Engineering, Biomedical Engineering, Medicine, Anatomy, Physiology, Cellular Biology, Molecular Biology, Hematology, Blood Physiological Phenomena, Hemorheology, Hematocrit, flow characteristics, flow measurement, flow visualization, rheology, Red blood cells, cross correlation, micro blood flows, microfluidics, microhemorheology, microcirculation, velocimetry, visualization, imaging
Combining monodisperse drop generation with inertial ordering of cells and particles, we describe a method to encapsulate a desired number of cells or particles in a single drop at kHz rates. We demonstrate efficiencies twice exceeding those of unordered encapsulation for single- and double-particle drops.
1Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 2Department for the Biology of Ageing, European Research Institute for the Biology of Ageing, University Medical Centre Groningen, University of Groningen, 3Institute of Biochemistry, ETH Zurich, 4Department of Health Sciences and Technology, ETH Zurich, 5Institute of Molecular Systems Biology, ETH Zurich
We describe here the operation of a microfluidic device that allows continuous and high-resolution microscopic imaging of single budding yeast cells during their complete replicative and/or chronological lifespan.
Published August 20, 2013. Keywords: Bioengineering, Microbiology, Cellular Biology, Molecular Biology, Biochemistry, Biomedical Engineering, Genetics, Anatomy, Physiology, Lifespan analysis, Live-cell imaging, Microfluidics, Aging, Microscopy, Saccharomyces cerevisiae, microfluidic chip, yeast, cell culture, cells, imaging
1Leibniz-Institut für Analytische Wissenschaften, ISAS, 2Department of Biochemical Engineering, University College London, 3Institute for Life Sciences, University of Southampton
Protocols for single neuron microfluidic arraying and water masking for the in-chip plasma patterning of biomaterial coatings are described. Highly interconnected co-cultures can be prepared using minimal cell inputs.
Published May 20, 2014. Keywords: Neuroscience, microfluidic arraying, single cell, biomaterial patterning, co-culture, compartmentalization, Alzheimer and Parkinson Diseases, neurite outgrowth, high throughput screening
1Mechanical Science and Engineering, University of Illinois at Urbana-Champaign
This paper introduces a 3D additive micromanufacturing strategy (termed ‘micro-masonry’) for the flexible fabrication of microelectromechanical system (MEMS) structures and devices. This approach involves transfer printing-based assembly of micro/nanoscale materials in conjunction with rapid thermal annealing-enabled material bonding techniques.
Published August 1, 2014. Keywords: Physics, Micro-masonry, microassembly, transfer printing, dry adhesives, additive manufacturing, printed processes, microfabrication, inks, microelectromechanical system (MEMS)
1The Rowland Institute, Harvard University
A microfluidic vortex assisted electroporation platform was developed for sequential delivery of multiple molecules into identical cell populations with precise and independent dosage control. The system’s size based target cell purification step preceding electroporation aided to enhance molecular delivery efficiency and processed cell viability.
Self-assembled monolayers (SAMs) formed from long chain alkane thiols on gold provide well-defined substrates for the formation of protein patterns and cell confinement. Microcontact printing of hexadecanethiol using a polydimethylsiloxane (PDMS) stamp followed by backfilling with a glycol-terminated alkane thiol monomer produces a pattern where protein and cells adsorb only to the stamped hexadecanethiol region.…
1Department of Mechanical Engineering, University of Michigan-Dearborn, 2Department of Surgery/Transplant, University of Illinois at Chicago, 3Department of Bioengineering, University of Illinois at Chicago
Microfluidic oxygen control confers more than just convenience and speed over hypoxic chambers for biological experiments. Especially when implemented via diffusion through a membrane, microfluidic oxygen can provide simultaneous liquid and gas phase modulations at the microscale-level. This technique enables dynamic multi-parametric experiments critical for studying islet pathophysiology.…
Published November 17, 2013. Keywords: Bioengineering, Islets of Langerhans, Microfluidics, Microfluidic Analytical Techniques, Microfluidic Analytical Techniques, oxygen, islet, hypoxia, intermittent hypoxia
We present methods for fabrication of patterned microstructures of vertically aligned carbon nanotubes (CNTs), and their use as master molds for production of polymer microstructures with organized nanoscale surface texture. The CNT forests are densified by condensation of solvent onto the substrate, which significantly increases their packing density and enables self-directed formation of 3D shapes.…