A supramolecular non-mesogenic route towards autonomous liquid crystal elastomer soft robots

Liquid crystal elastomers are unique choices for designing the next generation soft robots. Their synthesis relies exclusively on the polymerization/crosslinking of reactive mesogens with high molecular rigidity, necessitating high energy input to disrupt the molecular order for their actuation function. We report a non-mesogenic route towards designing liquid crystal elastomers. The monomeric precursors are non-mesogenic, but the supramolecular interactions are amplified in the polymerized network due to their cooperative nature, leading to liquid crystallinity. This allows resolving the common conflict between high actuation strain and low energy input, making it possible to design soft robots that can operate autonomously by harnessing the serendipitous energy from natural environments. Our molecular design broadens the scope of liquid crystalline materials, with potential implications beyond elastomeric actuators. Liquid crystal elastomers (LCEs) are promising materials for soft robotics due to their ability to undergo significant shape changes in response to thermal stimuli, but traditional methods of synthesizing LCEs often require high energy inputs and result in limited actuation performance. This study introduces a non-mesogenic approach to synthesize LCEs that enables high actuation strains at low temperatures, allowing for the development of autonomous soft robots that can operate using ambient thermal energy.