Dynamic healing-assembly for biocompatible, biodegradable, stretchable and self-healing triboelectric nanogenerators

[Display omitted] •The Cu2+ coordinated polyurethane (Cu-POU) with multiple functions were successfully prepared.•The Cu-POU is biocompatible, biodegradable, elastic and self-healing to meet the requirements of on-skin and implantable electronics and improve the stability and durability of resultant TENG.•The self-healing ability enables the assembly of an integrated TENG, as well as the preparation of sophisticated structure. Triboelectric nanogenerators (TENGs) have great potential as power sources for on-skin and implantable electronics. However, most existing TENGs are not suitable for the above applications due to limited material choices, often characterized by rigidity, susceptibility to damage, biological incompatibility, and non-biodegradability. Herein, we developed a simple self-healing assembly strategy based on introducing dynamic Cu(II)-dimethylglyoxime-urethane groups into a biocompatible and biodegradable polyurethane elastomer, to simultaneously address the above obstacles. The coordination of Cu2+ with dynamic bonds significantly enhanced the mechanical properties of elastomer, resulting in a modulus of 9.4 MPa and toughness of 40.2 MJ/m3. These bonds also gave the elastomer skin-like self-healing capabilities, achieving a healing efficiency of 77.5 % at 80 °C. Subsequently, a highly stretchable and integrated triboelectric nanogenerator (Cu-POU TENG) with self-healing capabilities was developed. The Cu-POU TENG with an effective area of 1.5 × 1.5 cm2 produced an open-circuit voltage of 38 V in single-electrode mode. The Cu-POU TENG could restore its original electrical properties through self-healing after mechanical damage. Furthermore, the Cu-POU TENG exhibited biocompatibility and biodegradability, making it suitable for on-skin and implantable electronics. Notably, the Cu-POU TENG maintained a stable voltage output throughout the degradation process. The integration of self-healing feature enabled a sophisticated structure, allowing the Cu-POU TENG to function effectively as a motion sensor for tracking body movement. This Cu-POU TENG holds great potential for applications in on-skin and implantable electronics.