Nano-Structure Enhanced Microfluidics Device for Spot Cooling

The Army is currently seeking advanced thermal management technologies for cooling localized hot spots in military vehicular power electronics. Electrowetting microfluidic devices provide highly-efficient discrete cooling with nano-liter volumes of fluid. The microdroplet is typically sandwiched between two hydrophobic coated electrodes. A control voltage is applied successively across multiple control electrodes, manipulating the interfacial forces, and transporting the fluid. State-of-the-art systems require large voltages (30-40 V) to initiate movement. A nano-structure enhanced microfluidics device is proposed that will reduce this large threshold voltage and increase heat transfer rates. In Phase I, Mainstream will fabricate and demonstrate the improved microfluidics device. Test results will be compared to other microfluidics devices found in the literature. A specific Army vehicle, power electronics system, and microelectronics device will be selected for analysis. In Phase II, Mainstream will fabricate an integrated microelectronics/microfluidics device and complete extensive testing. The technology will be ready for transition to the Army at the end of Phase II.