Room-temperature self-healing polysiloxane networks for highly sensitive piezoresistive pressure sensor with microdome structures

Abstract

Soft piezoresistive pressure sensor is an important component for next generation flexible electronics. Micropatterning of such sensors significantly improves the pressure sensitivity, however, the short device lifetime due to scratches and motions limits the translation to industrial applications. Herein, we report a novel poly(ODMS-co-MAA) for self-healing piezoresistive sensor to effectively overcoming such shortcoming. Self-healing capability was achieved by incorporating dynamic Fe(III)-carboxylate linkages in the polymer networks. These linkages work as sacrificial bonds and dissipate energy caused by mechanical damage. The bonds subsequently reform and functionality of the sensor can be restored. The poly(ODMS-co-MAA)-based self-healing polymer networks (SPN) were effectively healed from damages showing the recovery of electrical resistance (>95%) within 10 hrs. SPN was fabricated with microdome structures and exhibited a superior pressure sensitivity (2 kPa−1) as well as stability compared to planar features (9.13 × 10−3 kPa−1), demonstrating its excellent potential as pressure sensor. Combined results demonstrate the potential of the self-healing networks for next generation piezoresistive pressure sensors.