Understanding the Molecular Origin of the Collective Movement in a Diarylethene-based Photo-Responsive Actuator

Remotely controlling macroscopic movement is one of the key elements to realize intelligent materials for applications ranging from sensing to robotics. Over the last few years, a number of photomechanical materials based on diarylethene derivatives have been developed. However, a detailed picture of the structural evolution within these soft actuators is often missing. In this work, an atomistic investigation uncovers how the photo-induced molecular dynamics propagates to large-scale motion and results in macroscopic deformation of the crystal. By correlating the intramolecular rearrangement within the photo-responsive switching unit with the intermolecular packing, the molecular mechanism for the photomechanical phenomena is deciphered, which is fundamental for a rational development of photo-responsive actuators.