Electrowetting-driven heat switching in heat pipes: A novel concept

• A novel heat switch concept is introduced that eliminates most heat switch drawbacks. • Electrowetting is employed in a creative way to enable the heat switching. • The device is integrated into a heat pipe. • A basic proof-of-concept experiment is conducted and presented. The following article presents preliminary investigations into the potential use of an electrowetting gap in the realization of switchable heat pipes. In comparison with heat conductors made of solid materials, a heat pipe facilitates a substantially elevated heat flow density by leveraging the enthalpy of vaporization of a medium. Making the thermal resistance adjustable can lead to significant energy savings in thermal management systems. Existing switchable heat pipes are a relatively niche application due to downsides in their switching behavior, mass, integrability into existing system, or power consumption. In order to overcome the disadvantages of existing technologies, based on an electrowetting gap, the concept and results of a basic proof-of-concept experiment are presented. For the purpose of this study, the term Electrowetting Gap Heat Pipe (EWGHP) is introduced. Even if this experiment cannot yet be representative of an application, the development and its initial results show the potential of the technology and possible applications. The limitations of the experiment and an outlook for future research are also presented.