Self-healable polysiloxane/graphene nanocomposite and its application in pressure sensor

Polysiloxane is an ideal material for the preparation of wearable and flexible electronic devices. The preparation of pressure sensor using polysiloxane with both self-healing properties and excellent mechanical properties remains a key challenge. This work reports a self-healable pressure sensor based on polysiloxane network cross-linked by dynamic Diels–Alder bonds. The self-healable polysiloxane underwent a solid–liquid–solid transformation during a self-healing process, which has been confirmed by rheology. Depending on the amount of the linear reactive polydimethylsiloxane, mechanical performance and stretchability of the self-healable polysiloxane were tunable. By incorporating graphene nanosheets into polysiloxane elastomer, we fabricated a self-healable nanocomposite with significantly improved tensile stress and excellent electromechanical property. The tensile stress of nanocomposite containing 35 wt% graphene was 1.09 MPa that was improved by more than 1700% compared to that of the elastomer, indicating a significant improvement of the tensile stress with stretchability. The prepared self-healable pressure sensor exhibits a high sensitivity of 0.765 kPa⁻¹ and a gauge factor of 4.87, demonstrating a promising potential use in the pressure sensors.