A Fast Self-Healing Magnetic Nanocomposite for Magnetic Actuators

Magnetic actuators, which use magnetic effects for actuation, are very useful in many areas, such as electrical equipment, soft robots, and medical instruments. However, they inevitably suffer damage during long-term use, leading to mechanical failure. Introduction of the self-healing concept can solve this problem to a certain extent and extend their service life. Herein, a room-temperature self-healing magnetic nanocomposite is obtained using a simple, efficient, and environmental-friendly strategy. In the authors' design, soft poly(dimethylsiloxane) (PDMS) polymeric materials are chosen as the matrix, and Fe 3 O 4 nanoparticles are utilized as a functional magnetic nanofiller to obtain a new magnetic nanocomposite. By balancing the self-healing property and mechanical performance, the optimal content of magnetic filler is determined to be 15 wt%. The optimized sample exhibits an ultimate tensile strength (0.44 MPa), a high tensile strain (400%), and an excellent self-healing efficiency (62.2% mechanical recovery of fracture strength) at 25 °C for 30 min. Furthermore, this composite material shows an excellent and healable magnetic actuation performance. This new nanocomposite provides great potential for the magnetic actuation application.