Light-Controlled Actuation, Transduction, and Modulation of Magnetic Strength in Polymer Nanocomposites

Remotely controlled actuation with wireless sensorial feed‐back is desirable for smart materials to obtain fully computer‐controlled actuators. A light‐controllable polymeric material is presented, in which exposure to light couples with a change in magnetic properties, allowing light signal conversion into non‐volatile magnetic memory. The same material can serve, additionally, both as actuator and transducer, and allows the monitoring of its two‐way elastic shape‐changes by magnetic read‐out. In order to tune the macroscopic magnetic properties of the material, both the reorientation of i) shape anisotropic ferrimagnetic nano‐spindles and ii) a mechanically and magnetically coupled liquid‐crystalline elastomer (LCE) matrix are controlled. These materials are envisioned to have great potential for the development of innovative functional objects, for example, computer‐controlled smart clothing, sensors, signal encoding, micro‐valves, and robotic devices. An oriented liquid‐crystalline elastomer nanocomposite is synthesized and its light‐triggered reversible actuation is presented. Its performed shape changes can be wirelessly monitored on the basis of the remanent magnetization. This is due to the orientation changes of the incorporated magnetic nanoellipsoids. Both shape‐ and magnetization changes are temperature‐triggered either during illumination or through the atmosphere.