Waste heat recovery in an oscillating heat pipe using interfacial electrical double layers

This work presents the recovery of thermal energy through the oscillation of liquid plugs induced by phase transition within the oscillating heat pipe (OHP) during the quick heat-transfer process of the OHP. Using the electrical double layer at the liquid-solid interface in the OHP, this study demonstrated that the waste heat can be recycled and converted into useful electric energy. This recycling system generated more than 1 V of output voltage and more than 1.6 μW of peak power. The electric output generated from such a process can be used to power up small electronic devices, such as capacitors and light-emitting diodes (LEDs). The findings in this work provide an alternative approach to harvest waste heat in many devices or systems that involve the generation and removal of waste heat.