Spray cooling using silicon vibrating mesh atomizer

Aerosols are often used to cool surfaces, where the cooling rate is dependent on the liquid and aerosol properties, which are dependent on the method of atomization. Recent research determined that the size of droplets had a significant impact on cooling. This paper investigates the use of a Silicon-based microelectromechanical system (MEMS) vibrating mesh atomizer (VMA) to enhance cooling rates due to its narrow droplet size distribution. The presented work focuses on experimental analysis comparing the cooling performance of metallic and silicon VMA due to varying droplet size distribution. The study investigated cooling effects of three different liquids (DI water, isopropyl alcohol, and ethylene glycol coolant) onto a metal ceramic heater substrate. The silicon MEMS VMA was designed to have similar dynamic properties as the metallic VMA except for nozzle shape which affected the droplet size distribution and cone angle. The velocity and flow rate of the two devices were similar. It was demonstrated that the MEMS VMA had a significantly lower span or higher droplet distribution uniformity with all three liquids, reduced droplet size, and a larger spray angle. These parameters resulted in the MEMS VMA device being more effective at cooling the flat heated substrate compared to metallic VMA device.