Waste Silicone Rubber in Three-Dimensional Conductive Networks as a Temperature and Movement Sensor

Constructing a three-dimensional (3D) conductive network in a polymer matrix is a common method for preparing flexible sensors. However, the previously reported methods for constructing a 3D conductive network generally have shortcomings such as uncontrollable processes and insufficient network continuity, which limit the practical application of this method. In this work, we report a method for constructing a dual 3D conductive network. The carbon nanotube/graphene oxide co-continuous network (primary network) was introduced on the surface of the waste silicone rubber particles (WSRPs) through the adhesion of polydopamine (PDA), and then WSRPs were bonded into a porous skeleton using nanocellulose. The carbon fiber/carbon ball interconnection network (secondary network) was constructed in liquid silicone rubber (LSR) through the interaction of host-guest dendrimers and was filled into the WSRP skeleton. The dual 3D conductive network structure endowed the sensor with high electrical and thermal conductivity, outstanding stability, and excellent durability. In addition, the sensor showed high strain sensitivity and excellent stability when detecting human body temperature and motion behavior, and the pressure distribution can be spatially mapped through the sensor matrix. These demonstrations give our sensor high potential in the fields of smart devices, body monitoring, and human-machine interfaces.