Self-adaptive flow regulation through shape memory alloy valves for microelectronics cooling

To overcome the current limitations of temperature uniformity and high pumping power consumption of current microchannel cold plates, this work proposes to develop an on-chip liquid cooling system that incorporates self-adaptive shape memory alloy valves able to regulate the flow rate to the local and instantaneous needs of the chips, leading to energy savings and improved thermal performance of the microelectronics. The behavior of the valves is achieved due to the use of bimorph SMA wings. Thus, the valve remains closed for low cooling demands, maintaining a low flow rate at the channel and, when the cooling demands increase, the valve opens to allow more flow rate into the channel and improve its heat extraction capacity. It has been evaluated that the SMA valves can double the flow rate in the channel when in open position and the expected energy savings can be quantified between 10 % and 30 % for different heat load scenarios. Finally, the hysteresis of the SMA has been experimentally characterized for a determined working application.