Liquid-Metal-Filled Porous Elastomers for Highly Stretchable and High-Output Triboelectric Nanogenerators toward Wearable Electronics and Self-Powered Sensors.

Driven by the development of next-generation wearable and skin-attachable electronics, there is an escalating need for flexible self-powered systems, particularly for triboelectric nanogenerators (TENGs) that possess optimal dielectric properties and robust charge storage capabilities. However, it is challenging to achieve mechanical softness, high stretchability, and stable electrical outputs under continuous deformation due to the issue of structural failure under severe strains. Herein, we present a liquid-metal-filled porous elastomer (LMPE) architecture fabricated by foaming an Ecoflex 00-30 matrix using an aqueous suspension of LM droplets. In this structure, oxide-encapsulated LM microdroplets are strictly confined within independent pores of the matrix. This unique structural design enables the LMPE to simultaneously achieve skin-like mechanical compliance, stable dielectric properties, and superior triboelectric performance. The LMPE exhibits a low Young's modulus of ∼70-125 kPa and an exceptional fracture strain of up to ∼650%, enabling robust operation under repetitive deformation. Consequently, the LMPE-TENG delivers an open-circuit voltage of ∼169 V, a short-circuit current of ∼9.5 μA, a transferred charge of ∼63 nC, and a peak power density of 42.63 W·m-3. Notably, it maintains >95% of its initial output after 4 h of cyclic operation and 3 months of storage. System-level demonstrations, including capacitor charging, driving LED arrays, material recognition, Morse-code transmission, and human-machine interactive control, highlight its multifunctionality. This work provides a scalable soft-matter platform integrating LM with porous elastomers for high-performance wearable TENGs, self-powered sensing, and intelligent human-machine interactions.