Remote, fast actuation of programmable multiple shape memory composites by magnetic fields

Abstract

Nonwoven fiber composite Nafion/Fe₃O₄ films can be programmed to adopt over 5 shapes, and several fast transformations in sequence are demonstrated using different intensities of the same stimulus. We use an alternating magnetic field to activate the transformations remotely and investigate the conditions for tunable actuation control. Since the heat is generated inside the shape-changing films, though locally temperatures >80 or 100 °C are achieved, their surface temperature can be kept below 38–40 °C.