Magnetorheological elastomer (MRE)-based composites with high conductivity have received growing interest for a wide range of applications such as flexible electronics, soft robotics and magnetic monitoring. This work reports a stretchable and conductive magnetorheological elastomer (MRE) composite, which consists of carbonyl iron particles (CIPs)/polydimethylsiloxane (PDMS) magnetorheological matrix and liquid metal droplets (LMDs) filler. The mechanical and magnetic properties of the composites were firstly systematically investigated. The addition of CIPs improves the mechanical properties of the composite. When CIPs content increases to 30 wt%, the tensile strength reaches 478 kPa, which is mainly due to the increase of the elastic modulus. With the increase of CIPs contents, the saturation magnetization of the MRE-based composites also increases, showing good deformation ability under the action of magnetic field. Interestingly, the conductivity of the MRE-based composites could be reversibly switched through the contact and noncontact process between the LMDs, which helped to provide a basis model for the construction of conductive networks in magnetorheological elastomer based flexible composites. Combining magnetic and electrical properties, this MRE-based composite exhibits obvious stimulus-response characteristics under cyclic compression and magnetic field. Finally, the composite can be developed as a sensor for the detection of compressive force and magnetic field, the good sensing performance further demonstrated their broad promising in flexible electronics, magnetic sensing and wearable device.
 

magnetorheological elastomer composites,liquid metal droplets,mechanically sensitive conductivity,magnetic-mechanical detection