Gallium-based liquid metals are emerging materials for soft electronics with their fluidic compliance, low toxicity, metallic conductivity, and outstanding thermal conductivity. Especially, liquid metal particles (LMPs) mixed with polymeric matrix have demonstrated promising application potentials for soft and stretchable electronic applications including stretchable integrated circuits, capacitive sensors, dielectric elastomer actuators, and thermal management materials. This review highlights methods to prepare LMPs, control and manipulate LMPs within the polymeric matrix to meet the demands of different functionalities. Furthermore, we summarized recent advances by utilizing LMP composites to enable different stretchable electronic applications. It is believed that LMP composites will serve as important enabling materials for the development of electronic skins, stretchable electronics, smart textiles, and next-generation human-machine interfaces. A comprehensive and timely review of the recent progress in LMP composites is expected to inspire further exploration and innovation in stretchable and multifunctional electronic systems.

Triboelectric nanogenerators (TENGs) are emerging as new technologies to harvest electrical power from mechanical energy. With the distinctive working mechanism of triboelectric nanogenerators, they attract particular interest in healthcare monitoring, wearable electronics, and deformable energy harvesting, which raises the requirement for highly conformable devices with substantial energy outputs. Here, a simple, low-cost strategy for fabricating stretchable triboelectric nanogenerators with ultra-high electrical output is developed. The TENG is prepared using PTFE micron particles (PP-TENG), contributing a different electrostatic induction process compared to TENG based on dielectric films, which was associated with the dynamics of particle motions in PP-TENG. The generator achieved an impressive voltage output of 1000 V with a current of 25 μA over a contact area of 40 × 20 mm². Additionally, the TENG exhibits excellent durability with a stretching strain of 500%, and the electrical output performance does not show any significant degradation even after 3000 cycles at a strain of 400%. The unique design of the device provides high conformability and can be used as a self-powered sensor for human motion detection.