Microtechnology:
Manufacturing technology for making microscopic devices in the micrometer range (typically 1-100 micrometers), such as integrated circuits or Mems. The process usually involves replication and parallel fabrication of hundreds or millions of identical structures using various thin film deposition techniques and carried out in environmentally-controlled clean rooms.
JoVE Applied Physics
Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures
1Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, 2IMEC, Belgium
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.
JoVE General
Antifouling Self-assembled Monolayers on Microelectrodes for Patterning Biomolecules
1Department of Physics, Texas A&M University (TAMU), 2Department of Biomedical Engineering, Texas A&M University (TAMU)
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.
JoVE General
A Gradient-generating Microfluidic Device for Cell Biology
We describe a protocol for the microfabrication of the gradient-generating microfluidic device that can generate spatial and temporal gradients in well-defined microenvironment. In this approach, the gradient-generating microfluidic device can be used to study directed cell migration, embryogenesis, wound healing, and cancer metastasis.
JoVE General
A Microfluidic Device with Groove Patterns for Studying Cellular Behavior
We describe a protocol for the fabrication of microfluidic devices that can enable cell capture and culture. In this approach patterned microstructures such as grooves within microfluidic channels are used to create low shear stress regions within which cell can dock.
JoVE Applied Physics
Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy
Materials Sciences Division, Lawrence Berkeley National Laboratory
We have developed a self-contained liquid cell, which allows imaging through liquids using a transmission electron microscope. Dynamic processes of nanoparticles in liquids can be revealed in real time with sub-nanometer resolution.
JoVE General
A Multi-Parametric Islet Perifusion System within a Microfluidic Perifusion Device
1Department of Surgery, University of Illinois, Chicago, 2Department of Bioengineering, University of Illinois, Chicago
A microfluidic islet perifusion device was developed for the assessment of dynamic insulin secretion of multiple islets and simultaneous fluorescence imaging of calcium influx and mitochondrial potential changes.
JoVE Bioengineering
Creating Two-Dimensional Patterned Substrates for Protein and Cell Confinement
Department of Chemistry, Washington University in St. Louis
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.
JoVE Bioengineering
Endothelialized Microfluidics for Studying Microvascular Interactions in Hematologic Diseases
1Department of Pediatrics, Emory University School of Medicine, 2Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 3Aflac Cancer Center and Blood Disorders Service of Children's Healthcare of Atlanta, 4Winship Cancer Institute of Emory University
A method to culture an endothelial cell monolayer throughout the entire inner 3D surface of a microfluidic device with microvascular-sized channels (<30 μm) is described. This in vitro microvasculature model enables the study of biophysical interactions between blood cells, endothelial cells, and soluble factors in hematologic diseases.
JoVE General
Assessing Neural Stem Cell Motility Using an Agarose Gel-based Microfluidic Device
1Biomedical Engineering Department, Cornell University, 2Neurosurgical Laboratory for Translational Stem Cell Research, Weill Cornell Brain Tumor Center, Weill Cornell Medical College of Cornell University, 3Cell Morphology Department, Instituto de Investigacion Principe Felipe, 4Department of Chemical and Biomolecular Engineering, Cornell University
We demonstrate that the over expression of epidermal growth factor receptors (EGFR) enhances the motility of neural stem cells(NSCs) using a novel agarose gel based microfluidic device. This technology can be readily adaptable to other mammalian cell systems where cell sources are scarce, such as human neural stem cells, and the turn around time is critical.
JoVE General
The Microfluidic Probe: Operation and Use for Localized Surface Processing
Department of Biomedical Engineering, McGill University
In this video we present the microfluidic probe1 (MFP). We explain in detail how to assemble the MFP, mount it atop an inverted microscope, and align it relative to the substrate surface, and finally show how to use it to process a substrate surface immersed in a buffer solution.
JoVE General
Shrinky-Dink Hanging Drops: A Simple Way to Form and Culture Embryoid Bodies
School of Engineering, University of California Merced - UC Merced
We show a simple and rapid method to load pre-defined numbers of cells into microfabricated wells and maintain them for embryoid body development.
JoVE General
BioMEMS and Cellular Biology: Perspectives and Applications
Department of Biomedical Engineering, University of Washington
JoVE Bioengineering
Soft Lithographic Functionalization and Patterning Oxide-free Silicon and Germanium
1Department of Chemistry, Duke University, 2Hajim School of Engineering and Applied Sciences, University of Rochester, 3Department of Chemical Engineering, University of Rochester
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.
JoVE Bioengineering
Micropatterned Surfaces to Study Hyaluronic Acid Interactions with Cancer Cells
A novel approach that allows the high-resolution analysis of cancer cell interactions with exogenous hyaluronic acid (HA) is described. Patterned surfaces are fabricated by combining carbodiimide chemistry and microcontact printing.
JoVE General
Patterning Cells on Optically Transparent Indium Tin Oxide Electrodes
Department of Biomedical Engineering, University of California, Davis
Non-fouling PEG silane monolayer was desorbed from individually addressable ITO electrodes on glass by application of a reductive potential. Electrochemical stripping of PEG-silane layer from ITO microelectrodes allowed for cell adhesion to take place in a spatially defined fashion, with cellular patterns corresponding closely to electrode patterns.
JoVE General
AC Electrokinetic Phenomena Generated by Microelectrode Structures
1Biomedical Engineering, Science and Health Systems, Drexel University, 2Mechanical Engineering and Mechanics, Drexel University
Manipulating fluids and suspended particles in the micro- and nano-scale is becoming more of a reality as enabling technologies, like AC electrokinetics, continue to develop. Here, we discuss the physics behind AC electrokinetics, how to fabricate these devices and how to interpret the experimental observations.
JoVE General
Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation
1Institute for Biological Interfaces, Karlsruhe Research Centre, 2Institute for BioMedical Technology, University of Twente, 3Department of Materials Research, Institute for Heavy Ion Research, 4Institute of Microstructure Technology, Karlsruhe Research Centre, 5Institute for Micro Process Engineering, Karlsruhe Research Centre
We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.
JoVE General
Microfabricated Post-Array-Detectors (mPADs): an Approach to Isolate Mechanical Forces
1Department of Bioengineering, University of Pennsylvania, 2University of Washington
In this video, we demonstrate how to fabricate and utilize microfabricated post array detectors (mPADs) to assess modulations of cellular contractility.
JoVE General
Silicon Microchips for Manipulating Cell-cell Interaction
Laboratory for Multiscale Regenerative Technologies, MIT - Massachusetts Institute of Technology
This article describes an experimental approach for dynamic regulation of cell-cell interactions between adherent cells on a micrometer scale. Manipulation of intercellular communication between hepatocytes and stromal cell is demonstrated. The developed platform enables investigation of cell-cell interactions in a variety of biological processes, including development and pathogenesis.
JoVE Editorial
July 2012: This Month in JoVE
1JoVE Content Production, 2Department of Ophthalmology, Massachusetts Eye and Ear
Historically, JoVE, The Journal of Visualized Experiments, has focused primarily on biomedical research and has developed subsections for Bioengineering, Clinical and Translational Medicine, Immunology and Infection, and Neuroscience. This July, JoVE launches its Applied Physics section, which includes a range of content from Plasma Physics to Materials Science. We begin the new section with a notable article from Purdue University, where researchers in the Center for Laser-Based Manufacturing are studying.
JoVE General
Microfluidic Co-culture of Epithelial Cells and Bacteria for Investigating Soluble Signal-mediated Interactions
1McFerrin Department of Chemical Engineering, Texas A&M University, 2Department of Biomedical Engineering, Texas A&M University
This protocol describes a microfluidic co-culture model for simultaneous and localized culture of epithelial cells and bacteria. This model can be used for investigating the role of different soluble molecular signals on pathogenesis as well as screen the effectiveness of putative probiotic bacterial strains.
JoVE Bioengineering
Separating Beads and Cells in Multi-channel Microfluidic Devices Using Dielectrophoresis and Laminar Flow
1Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 2Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, 3Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 4Bioengineering, University of Illinois at Urbana-Champaign
Dielectrophoresis (DEP) is an effective method to manipulate cells. Printed circuit boards (PCB) can provide inexpensive, reusable and effective electrodes for contact-free cell manipulation within microfluidic devices. By combining PDMS-based microfluidic channels with coverslips on PCBs, we demonstrate bead and cell manipulation and separation within multichannel microfluidic devices.
JoVE Bioengineering
Fabrication of Micropatterned Hydrogels for Neural Culture Systems using Dynamic Mask Projection Photolithography
Biomedical Engineering, Tulane University
Simple techniques are described for the rapid production of microfabricated neural culture systems using a digital micromirror device for dynamic mask projection lithography on regular cell culture substrates. These culture systems may be more representative of natural biological architecture, and the techniques described could be adapted for numerous applications.
JoVE Applied Physics
Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates
Mechanical and Aerospace Engineering, University of Texas at Arlington
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.
JoVE Applied Physics
A Method to Fabricate Disconnected Silver Nanostructures in 3D
1School of Engineering and Applied Sciences, Harvard University, 2Department of Physics, Harvard University
Femtosecond-laser direct-writing is frequently used to create three-dimensional (3D) patterns in polymers and glasses. However, patterning metals in 3D remains a challenge. We describe a method for fabricating silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm.
JoVE General
Microcontact Printing of Proteins for Cell Biology
Department of Biomedical Engineering, Columbia University
Microcontact printing is used extensively to pattern proteins and other molecules on material surfaces. We demonstrate the basic steps of this process, stamping patterns of fibronectin onto glass.
JoVE Bioengineering
Decellularization and Recellularization of Whole Livers
Perfusion decellularization is a novel technique to produce whole liver scaffolds that retains the organ's extracellular matrix composition and microarchitecture. Herein, the method of preparing whole organ scaffolds using perfusion decellularization and subsequent repopulation with hepatocytes is described. Functional and transplantable liver grafts can be generated using this technique.
JoVE General
A Microfluidic Device for Quantifying Bacterial Chemotaxis in Stable Concentration Gradients
1McFerrin Department of Chemical Engineering, Texas A&M University, 2Department of Biology, Texas A&M University, 3Department of Biomedical Engineering, Texas A&M University
This protocol describes the development of a microfluidic device for investigating bacterial chemotaxis in stable concentration gradients of chemoeffectors.
JoVE Bioengineering
High Throughput Single-cell and Multiple-cell Micro-encapsulation
Department of Mechanical Engineering, Vanderbilt University
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.
JoVE Bioengineering
Bridging the Bio-Electronic Interface with Biofabrication
1Fischell Department of Bioengineering, University of Maryland, 2Institute for Bioscience and Biotechnology Research, University of Maryland, 3Department of Materials Science and Engineering, University of Maryland
This article describes a biofabrication approach: deposition of stimuli-responsive polysaccharides in the presence of biased electrodes to create biocompatible films which can be functionalized with cells or proteins. We demonstrate a bench-top strategy for the generation of the films as well as their basic uses for creating interactive biofunctionalized surfaces for lab-on-a-chip applications.
JoVE Bioengineering
Creating Transient Cell Membrane Pores Using a Standard Inkjet Printer
Department of Bioengineering, Clemson University
A description of the methods used to convert an HP DeskJet 500 printer into a bioprinter. The printer is capable of processing living cells, which causes transient pores in the membrane. These pores can be utilized to incorporate small molecules, including fluorescent G-actin, into the printed cells.
JoVE Bioengineering
Simple Microfluidic Devices for in vivo Imaging of C. elegans, Drosophila and Zebrafish
1Neurobiology, NCBS-TIFR, 2Department of Biological Sciences, TIFR
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.
JoVE Neuroscience
A Galvanotaxis Assay for Analysis of Neural Precursor Cell Migration Kinetics in an Externally Applied Direct Current Electric Field
1Institute for Biomaterials and Biomedical Engineering, University of Toronto, 2Lyndhurst Centre, Toronto Rehabilitation Institute, 3Department of Surgery, University of Toronto
In this protocol we demonstrate how to construct custom chambers that permit the application of a direct current electric field to enable time-lapse imaging of adult brain derived neural precursor cell translocation during galvanotaxis.
JoVE Chemistry
Origami Inspired Self-assembly of Patterned and Reconfigurable Particles
1Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 2Department of Chemistry, The Johns Hopkins University
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.
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