Development of One-sided Actuating Piezoelectric Micropump Combined with Cold Plate in a Laptop

We investigated a new one-sided actuating piezoelectric micropump combined with a cold plate (OAPCP-micropump) in a liquid cooling system to solve heat dissipation problems and to improve electronic device reliability for a laptop. The OAPCP-micropump, which is composed of a PDMS diaphragm, a 45 mm times 28 mmtimes 4 mm pump chamber with added fins, a rectangular piezoelectric device, and two check valves, can allow a thinner design and drive liquid in one direction. The results show that the shape of the fins has a strong effect on the pressure drops and flow profiles. The fluid in the pump chamber may impinge on the fins and increase the heat dissipation rate due to the oscillation by the actuator. When the fins are shorter than 1.25 mm, they have a negligible effect on the performance of the OAPCP-micropump. In addition, increasing the number of fins from 6 to 12 can enhance the heat dissipation rate but has no influence on the flow rate. The measured maximum flow rate of the OAPCP-micropump is 4.1 ml/s, and its maximum pump head reaches 9807 Pa. In general, the new cooling system with an OAPCP-micropump design shows a stable performance on total thermal resistance due to the high flow rate.