Microfabrication of Bubble Cavities in PDMS for Cell Sorting and Storage Applications

Abstract

We describe a novel technique, low surface energy gas expansion molding (GEM), to fabricate microbubble arrays in polydimethylsiloxane (PDMS) which are incorporated into parallel plate flow chambers and tested in microcell culture and cell sorting applications. This architecture confers several operational advantages that distinguish this technology approach from the current state. Here in we describe the GEM molding process and the parameters that are used control microbubble formation. We introduce a vacuum-assisted coating process developed to selectively and spatially alter the PDMS surface chemistry in the wells and on the microchannel surface. We describe results from preliminary microparticle image velocimetery (μPIV) studies conducted to investigate fluid streams above and within microbubble wells and conclude with a discussion of our initial efforts to integrate optical sensors in PDMS.