Specific design and implementation of a piezoelectric droplet actuator for evaporative cooling of free space

We report the experimental results of evaporative cooling effect of a novel piezoelectric droplet actuator designed for a free space utilizing dynamic infrared thermographs as their space-time courses of temperatures recorded. These droplets of pure water were jetted as working liquid of an evaporating cooling system comprising a PZT micro-actuator, controller and liquid delivery for the circulation of air with the cooling space. Cyclic cooling tests demonstrated that these micro droplets well performed the evaporative cooling effectively. The space cooling for such an evaporative cooling system was studied by a high-performance infrared imager that enabled all the temperature changes of the space to be recorded and analyzed per three seconds, yielding uniform water droplets (<; 100 μm) with cooling rate ~ -1.1°C/min.