Robust and durable triboelectric nanogenerators enabled by a mechanically strong and mildly healable polymer

The capability of healing structural damage is highly desired for triboelectric nanogenerators (TENGs), which are subject to repeated mechanical loading. However, it remains difficult to balance the intrinsic mechanical strength and healing capability of the materials used in TENGs. Herein, we exploit a mechanically strong and mildly healable polymer (THP) as the key material of TENGs. THP is based on polyurethane-urea containing coordinate bonds, and its healing can be triggered by simply wetting the breakage area with water or alcoholic drinks. The healing ratio and the tensile strength of THP can reach ∼90% and ∼11.6 MPa, respectively. Correspondingly, the prepared THP-based TENGs (THP-TENGs) exhibit high enough robustness to withstand mechanical loading as well as excellent healability for recovering device functionalities after mechanical damage. In addition, disused devices can be recycled to produce new ones based on the solution processibility of THP. The fabricated THP-TENG could serve as a mechanical energy harvester as well as a self-powered sensor for detecting tactile and electrophysiological signals, suggesting utilities in advanced wearable systems.