A backflow-suppressing piezoelectric MEMS cooler for thermal management within confined spaces

Rapid advances in compact electronic devices have led to severe thermal management challenges in inherently confined internal spaces, where pump characteristics are required for air coolers to maintain their cooling effectiveness. In the present work, for the first time, a silicon-based piezoelectric jet pump is developed as a MEMS cooler. This MEMS air cooler with backflow suppression is realized by incorporating a piezoelectric MEMS actuator array with a multi-orifice outlet configuration. With a compact footprint of 9 × 9 × 1.7 mm3, the cooler achieves a back pressure of 300 Pa and a volume-normalized flow rate of 2.3 L ⋅ min−1 ⋅ cm−3. With a power consumption level of only 11 mW, it removes ∼500 mW of heat flow rate at a heater–cooler distance as small as 1 mm. In addition, quiet operation can be achieved by extending the driving frequency to the ultrasonic range. This MEMS air cooler represents an ideal solution with a compact size, high flow rate, low power, and low noise, showing strong potential for revolutionizing the landscape of miniaturized active cooling.