Integrated circuit technology continues to progress in the direction of higher device density and with it, a higher density of waste heat that must be removed in order to maintain the electronics below their desired operating temperatures. In the majority of applications, including personal computers and workstations, cellular phones, hand-held electronics, and automotive applications, economic and other practical considerations restrict thermal management solutions to air-cooled systems. Air cooling technology is often the limiting factor in determining the size and performance of electronic products, and novel concepts to improve air cooling capabilities are much needed. The goal of the proposed work is to produce ion driven air flow at the microscale, integrated within micro-featured heat generating surfaces. It is the aim of this work to fill a technological gap in microscale convective cooling by developing a pump that is itself truly at the microscale. The key advancement proposed in this work is the generation of unipolar ions in air. A single ion species can be accelerated in an electric field, efficiently creating fluid motion. Preliminary calculations of the heat transfer rates achievable using ion driven pumping of air through microchannels show that as much as 40 W/cm2 of heat rejection is possible by this technique. This cooling rate compares favorably to those in many liquid-cooled applications and would provide an air-cooling alternative to meet the needs of future semiconductor devices. Funding is being provided by the Thermal Transport and Thermal Processing Program of the Chemical and Transport Systems Division.
