Variable Pumping Control for Low Power Microfluidic Chip Cooling

As microelectronic modules increase in power density, liquid cooling has become increasingly required to maintain acceptable chip temperatures. Liquid cooling in microchannels offers low thermal resistance and can be integrated into modules given their small size and implementation by microfabrication methods [1]. Microchannel cooling is therefore particularly well suited for embedded or portable applications. Their performance and compact form factor come, however, to the cost of increased pressure drop compared to larger scale cold plates. Since energy is limited in portable applications, power consumption by the cooling system (product of pressure drop and flow rate) should be minimized. This can be done by reducing the pressure drop with optimal design [2] or by distributing the flow in parallel microchannels or cell arrays [3], [4]. This work focuses on reducing the flow rate by adapting the pumping conditions to only provide the minimal flow rate required to maintain the maximum chip temperature.