Evaporation-cooling-based microfluidic temperature control and ice generation

Abstract

We report water-based evaporative cooling for temperature control and ice generation, integrated into a microfluidic device. We opt for water as nontoxic and effective refrigerant. Owing to low pressure (∼9.3 kPa) and large surface-to-volume ratio, atomized water droplets evaporate readily, resulting in efficient heat removal. Upon applying vacuum, the temperature decreases at fast as -5.1°C/s, and the refrigeration temperature as low as -13.8°C is achieved. By using aqueous solution as refrigerant, we also demonstrate ice generation and freezing of biofluid without any external cooling element. Our novel cooling method may contribute significantly to microfluidic chemical and biological assays, where accurate temperature control and cooling/freezing are essential. © 14CBMS.