Experimental investigation of a heat switch based on the precise regulation of a liquid bridge

Thermal management is a key issue in various fields of engineering. The effective counterplan has to be come up with for achieving high thermal stability suitable for thermally-sensitive system. Here, the concept utilizing a liquid-based heat switching method was presented as one of the promising solutions in the thermal management, and the proposed system is composed of a hot plate, cold plate, fluid chamber and actuator. The heat switching works by means of controlling the formation of the liquid bridge between the two plates, and it enables to not only control the thermal resistance but also distribute the heat to the surroundings using the liquid bridge. Thus, the thermal performance of the proposed heat switch highly depends on the formation and motion of the liquid bridge. Empirically, the optimal geometry of the heat switch, the diameter of the liquid channel and clearance between two plates, was determined to be suitable for creating and rupturing the liquid bridge. To investigate the effects of its geometry, the pressure analysis and observation of the liquid bridge through CCD were conducted, respectively. The constructed heat switching system was applied to the LED-based testing module to control the LED junction temperature regulation and thermal resistance between the LED plate and the heat sink. As a result, the behavior of the liquid bridge and its effect on the heat switching were empirically understood.