A flexible multifunctional sensor with a conductive network based on silk nanofibers and MXene for monitoring physiological activity, capacitive pens, photothermal conversion and antibacterial

Flexible electronic sensors that can capture subtle physical, chemical and biological signals and generate real-time stimulus responses are of great importance in the fields of human–computer interaction, biomedicine, etc. Herein, a multifunctional sensing hydrogel was developed by tightly adhering two-dimensional rigid conductive MXene nanosheets to the surface of vimineous silk nanofibers (SNFs) and assembling them into an SNF@MXene network structure. Polyvinyl alcohol (PVA) was then in situ polymerized in SNF@MXene as a filling matrix. MXene nanosheets were attached to the SNF network skeleton, avoiding the settlement and aggregation of MXene and forming a PSM composite hydrogel with a uniform and dense conductive network. The designed PSM hydrogel-based sensor showed excellent mechanical properties (tensile strength = 5.07 MPa), wide operating range (700.6 %), high sensitivity (gauge factor = 8.2), high electrical conductivity (1.64 S m −1 ), and adhesion. The sensor could detect various physiological activities of the human body. In addition, it also showed the application potential in speech recognition, capacitive pen, etc. PSM exhibited excellent photothermal conversion efficiency. It could be rapidly heated to 82.8 °C under NIR irradiation and used for photothermal therapy. This study provides a simple conductive network design strategy for the fabrication of flexible electronic devices with multiple functions.