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.