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Parallel mixing of photolithographically defined nanoliter volumes using elastomeric microvalve arrays
Author(s) -
Li Nianzhen,
Hsu ChiaHsien,
Folch Albert
Publication year - 2005
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200500171
Subject(s) - polydimethylsiloxane , microfluidics , mixing (physics) , materials science , fluidics , nanotechnology , photolithography , biomedical engineering , medicine , physics , quantum mechanics , aerospace engineering , engineering
Portable microfluidic systems provide simple and effective solutions for low‐cost point‐of‐care diagnostics and high‐throughput biomedical assays. Robust flow control and precise fluidic volumes are two critical requirements for these applications. We have developed a monolithic polydimethylsiloxane (PDMS) microdevice that allows for storing and mixing subnanoliter volumes of aqueous solutions at various mixing ratios. Filling and mixing is controlled via two integrated PDMS microvalve arrays. The volumes of the microchambers are entirely defined by photolithography, hence volumes from picoliter to nanoliter can be fabricated with high precision. Because the microvalves do not require an energy input to stay closed, fluid can be stored in a highly portable fashion for several days. We have confirmed the mixing precision and predictability using fluorescence microscopy. We also demonstrate the application of the device for calibrating fluorescent calcium indicators. Due to the biocompatibility of PDMS, the device will have broad applications in miniaturized diagnostic assays as well as basic biological studies.