title: Self-actuated, thermo-responsive hydrogel valves for lab on a chip.
abstract: An easy to fabricate, thermally-actuated, self-regulated hydrogel valve for flow control in pneumatically driven, microfluidic systems is described. This microvalve takes advantage of the properties of the hydrogel, poly(N-isopropylacrylamide), as well as the aqueous fluid itself to realize flow control. The valve was designed for use in a diagnostic system fabricated with polycarbonate and aimed at the detection of pathogens in oral fluids at the location of the sample collection. The paper describes the construction and characterization of the hydrogel valves and their application for flow control, sample and reagent metering, sample distribution into multiple analysis paths, and the sealing of a polymerase chain reaction (PCR) reactor to suppress bubble formation. The hydrogel-based flow control is electronically addressable, does not require any moving parts, introduces minimal dead volume, is leakage and contaminant free, and is biocompatible.
authors.affiliation: Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Zongyuan
authors.initials: Z
authors.lastname: Chen
authors.forename: Michael
authors.initials: M
authors.lastname: Mauk
authors.forename: Kuang-Sheng
authors.initials: KS
authors.lastname: Hong
authors.forename: Mengyan
authors.initials: M
authors.lastname: Li
authors.forename: Shu
authors.initials: S
authors.lastname: Yang
authors.forename: Haim H
authors.initials: HH
authors.lastname: Bau
mesh_terms: D000180:Acrylic Resins / Q000032:analysis / Q000737:chemistry*; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry*; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods; D020100:Hydrogels / Q000032:analysis / Q000737:chemistry*; D008422:Materials Testing; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D008956:Models, Chemical; D016133:Polymerase Chain Reaction / Q000295:instrumentation* / Q000379:methods; D013696:Temperature
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D020100:Hydrogels; C052970:poly-N-isopropylacrylamide