A Digital-Microfluidic Approach to Chip Cooling

Thermal management has emerged as an increasingly important aspect of IC design. Elevated die temperatures are detrimental to circuit performance and reliability. Furthermore, hot spots due to spatially nonuniform heat flux in ICs can cause physical stress that further reduces reliability. The authors of this article review various chip-cooling techniques that have been proposed in the literature. They then present an alternative approach based on a recently invented digital-microfluidic platform that enables an adaptive cooling technique. This novel digital-fluid-handling platform uses a phenomenon known as electrowetting so that a vast array of discrete droplets of liquid, ranging from microliters to nanoliters and potentially to picoliters, can be independently moved along a substrate. Although this technology was originally developed for a biological and chemical lab on a chip, the authors show how it can be adapted for use as a fully reconfigurable, adaptive cooling platform.