Biomimetic snapping of polyhexahydrotriazine tough actuator driven by supramolecular interaction

The design of materials that can simulate the magical and complex phenomena in nature through simple theoretical and process design are essential and challenging. Here we describe a tough polyhexahydrotriazine film actuator bent in response to dichloromethane through simple theory and technological design, and its curving behavior is consistent with the snapping of a Venus flytrap. Theoretical calculation demonstrates that the driving force of the actuator derives from the C–H/ π interaction and halogen bond interaction between dichloromethane and polymer chains. Driven by two supramolecular interactions, the actuator bends and accumulates elastic potential energy, releasing elastic potential energy through snapping deformation, which can lift objects 20 times heavier than itself. Over time, the actuator remains bent, and the degree of bending increases, allowing it to wrap tightly around the object, with potential applications in protective materials and intelligent crawling systems. In addition, the actuator possesses good mechanical properties, solvent resistance, and thermal properties, with the ability to resist extreme conditions.