Photoresponsive Fuel Molecules for Energy-Embodied

This study presents a molecular approach for integrating a responsive chemical fuel into a robotic system. A photocleavable carrier was designed to temporarily immobilize hexafluoroisopropanol (HFIP), a surface-tension-active fuel capable of Marangoni propulsion. In this dormant state, the fuel can be stored with minimal loss yet activated on demand by light. Upon UV irradiation, photochemical cleavage of the carrier releases HFIP, generating localized surface-tension gradients that drive mechanical motion. To translate this concept into robotic materials, the fuel carrier was incorporated into a polymer matrix, enabling films or coatings with embedded fuel-storage capability. These resultant composites were able to provide light-addressable actuation in a range of model systems, including micropumps, surface-tension-mediated cargo transport, and hybrid microrobots combining photochemical propulsion with magnetic guidance.