Ultrastretchable, Wearable Triboelectric Nanogenerator Based on Sedimented Liquid Metal Elastomer Composite

Abstract Progress in soft and stretchable electronics depends on energy sources that are mechanically compliant, elastically deformable, and renewable. Energy harvesting using triboelectric nanogenerators (TENGs) made from soft materials provides a promising approach to address this critical need. Here, an elastomeric composite is introduced with sedimented liquid metal (LM) droplets for TENG‐based energy harvesting that relies on assembly of the LM to form phase‐separated conductive and insulating regions. The sedimented LM elastomer TENG (SLM‐TENG) exhibits ultrahigh stretchability (strain limit > 500% strain), skin‐like compliance (modulus < 60 kPa), reliable device stability ( > 10 000 cycles), and appreciable electrical output performance (max peak power density = 1 mW cm −2 ). SLM‐TENGs can be integrated with highly elastic stretchable fabrics, thereby enabling broad integration with wearable electronics. A stretchable and wearable SLM‐TENG is demonstrated that harvests energy from human motion through a patch attached to the knee or integrated into exercise clothing. This body‐mounted TENG device can generate enough electricity to fully power a wearable computing device (hygro‐thermometer with digital display) after 2.2 min of running on a treadmill.