Liquid metal architectures for soft and wearable energy harvesting devices

Future advanced wearable energy harvesters need to have high power densities, functionality under large deformations, scalability, and robust resistance against mechanical damages (i.e. fatigue, delamination, and fracture). To achieve this, ultra-flexible, high dielectric, and thermally conductive materials along with deformable and robust electrodes are needed. Here, we review recent progress in synthesis and integration of liquid metal (LM) material architectures as the building blocks of emerging wearable energy harvesting devices. After a brief introduction to room temperature LM alloys, LM's various applications in a variety of soft and stretchable power harvesting devices including thermoelectric, triboelectric, dielectric elastomer, and piezoelectric generators are summarized. The unique opportunities and challenges introduced by LM material architectures in this field are also discussed.