Teaching Materials - Introduction to BioMEMS - page 460

microchannel into a large chamber, the particles come out sorted by size. he technique
was invented by Minoru Seki and colleagues from Osaka Prefecture University in 2004.
pinch-valves: Valves that use mechanical force to reduce the diameter of a section of the tubing
through which the luid is lowing. In 2000, Stephen Quake and coworkers devised a way
to “pinch” a PDMS microchannel using a second air-illed microchannel (called “control
channel”) on top of the luid-carrying one and separated by a thin (~30 μm) PDMS gap;
these microfabricated PDMS pinch-valves are popularly known as “Quake valves”; see
Quabe microvalve.
PIV: See particle imaging velocimetry.
PLGA: See poly(dl-lactic-co-glycolide).
PLL: See poly-l-lysine.
plug low proile: Flow proile characterized by a constant low speed across the whole cross-
section of the pipe, typically achieved in electro-osmotic low; see electro-osmotic low.
poly(dimethyl siloxane): Transparent elastomer that is widely used in BioMEMS and sot
lithography for the molding of microdevices.
poly(dl-lactic-co-glycolide): Biodegradable thermoplastic polymer that is approved by the
FDA for therapeutics.
poly(ethylene glycol): A biocompatible polymer used as an active ingredient or as an additive by
the food and pharmaceutical industries (e.g., in laxatives, skin creams, eye drops, and
ointments); in BioMEMS and tissue engineering, PEG is used to block protein adsorp-
tion on surfaces.
poly(ethylene glycol) diacrylate: A photopolymeryzable version of PEG.
poly(ethylene oxide): Synonymous of poly(ethylene glycol). See PEG.
poly(glycerol sebacate acrylate): Transparent biodegradable elastomer.
poly(glycerol sebacate): Transparent biodegradable elastomer.
poly-d-lysine: A common tissue culture coating for enhancing cell and protein adhesion. Poly-
d-lysine and poly-l-lysine are enantiomers (they only difer in the sterical assembly of
the atoms in the molecule); poly-d-lysine is convenient because, unlike poly-l-lysine, it
cannot be degraded by cellular proteases.
poly-l-lysine: A small natural homopolymer of the amino acid l-lysine that is produced by bac-
terial fermentation and that is used as a common tissue culture coating for enhancing
cell and protein adhesion.
poly( N -isopropylacrylamide): A hydrogel polymer that undergoes a reversible phase transition
(becoming insoluble) when heated to more than 32°C.
poly-NIPAM: See poly( N -isopropylacrylamide).
positive dielectrophoresis: Dielectrophoresis scenario in which the solvent is of lower polariz-
ability than the particle, resulting in the movement of the particle toward the electrical
ield maxima ; see dielectrophoresis.
positive photoresist: Photoresist that, if exposed to the correct light, dissolves in the developer
solution; see photoresist, developer.
protein crystallization chips: Microluidic chips used to produce large numbers of microscale
protein crystals in a parallel array of various conditions; the chips, thus help optimize
which condition produces the best crystal and are an improvement in screening speed of
several orders of magnitude over the serial trial-and-error procedure that has been used
traditionally.
protein immunoblot: See Western blot.
Q
Quake microvalve: First design of microvalve fabricated integrally in PDMS; the microvalve was
developed by Stephen Quake's laboratory, then at Caltech, in 2000; see pinch-valves.