A triboelectric sensing array integrating material identification and self-healing enabled by a healable polyamide-based device unit

To develop skin-like tactile sensor systems with both self-healing ability of repairing mechanical damage and perception ability of identifying materials and objects is significantly valuable for smart and high-quality interaction with environment. It is noticed that the sensing array comprised of distinct triboelectric nanogenerator (TENG) units shows great advantages in material recognition. However, those attempts of integrating self-healing ability into above triboelectric sensing array are challenged by the lack of self-healing TENG constituent units with differentiated electron affinity . Herein, we exploit a self-healing polyamide (SPA) with high mechanical strength as the base material for constructing a novel self-healing TENG unit with distinctive electron affinity. The healing of the prepared SPA-based TENG (SPA-TENG) can be autonomously conducted at room temperature without external intervention required. Our results reveal that SPA-TENG possesses stronger electron affinity compared to existing self-healing TENGs, which enables it to be an ideal constituent unit to construct self-healing triboelectric sensing array for material identification. After combining SPA-TENG with other previously reported self-healing TENGs, we firstly demonstrate a fully self-healing triboelectric sensing array capable of distinguishing various commercial plastic products based on their fingerprint waveform combinations, which shows promising application in fields of intelligent robots, artificial prosthesis , and automatic production etc.