Optoelectronic reconfigurable microchannels†
This paper reports a new optoelectronic reconfigurable microchannel (OERM) technology which uses low-power light to create and reconfigure microchannels within seconds. This technology thereby removes the need for complicated, on-chip fluidic interconnects and enables real-time modification of microchannel networks. In essence, OERM technology is based on the local thawing of a frozen solution using an optoelectronic heating effect powered by an external voltage supplier; a light pattern of microchannels is projected on an OERM chip containing a thin layer of frozen liquid, which produces microchannels corresponding to the light pattern via melting. When the pattern is modified, specific regions freeze and others melt according to the new light pattern, which causes the microchannel network to reconfigure. The versatility of this platform is illustrated by performing several experiments: single-phase flows are used to draw a smiley-face pattern, and multi-phase flow operations, such as generating and merging droplets and bubbles are demonstrated. Due to its low optical power requirement and its fast reconfiguration speed, OERM can dynamically alter microfluidic circuits while benefiting from the flexibility of light patterns and thereby offers a myriad of possible microfluidic applications.