Microstructured Self-Healing\nFlexible Tactile Sensors\nInspired by Bamboo Leaves

Wearable electronic devices with multifunctions such\nas flexible,\nintegrated, and self-powered play a crucial role in the fields of\nhealth monitoring, motion monitoring, and human–computer interaction.\nHowever, their core basic components, flexible pressure sensors, face\nchallenges including poor long-term stability and insufficient real-time\nsensing accuracy. In order to solve the challenges of long-term, stable,\nand accurate sensing of the sensor, this paper prepares polydimethylsiloxane\n(SHPDMS) with intrinsic self-healing property and designs a high-sensitivity\nself-healing capacitive flexible pressure sensor with dual microstructures\n(grating microstructured electrodes and microporous dielectric layer)\nas the substrate based on SHPDMS. Specifically speaking, the self-healing\nof the sensor under mild conditions was realized by introducing reversible\nimine bonds with low bonding energy into the polydimethylsiloxane\n(PDMS) flexible substrate, which solved the problem of the material’s\nlong-term service durability. A grating-like microstructure was introduced\ninto the flexible electrode by using a spotted bamboo taro leaf as\na template, and a dual microstructure sensor was constructed by combining\nit with a microporous dielectric layer doped with single-walled carbon\nnanotubes. This way reduces the elastic modulus of the dielectric\nlayer, improves the dielectric constant of the sensor under loading,\nand thus significantly improves the sensor’s sensitivity and\nextends the measurement accuracy in a low-stress range. The prepared\nself-healing flexible sensor achieves a sensitivity of 3.6 kPa<sup>–1</sup>, a minimum detection limit of 5 Pa, a response recovery\ntime of less than 80 ms, and stability over 5000 cycles, which exceeds\nmost previously reported silicone rubber-based capacitive flexible\nsensors.