Chromatic Photo-thermal Actuators based on 2H-MoS_2 based Nanocomposites

摘要

The ability to convert photons of different wavelength directly into mechanical motion is of significant interest in many energy conversion and reconfigurable technologies. Using few layer 2H-MoS_2 nanosheets, layer by layer process of nanocomposite fabrication, and strain engineering, we demonstrate a reversible and chromatic mechanical response in MoS_2-nanocomposites between 405 nm to 808 nm with large stress release. The chromatic mechanical response originates from the d orbitals and is related to the strength of the direct exciton resonance A and B of the few layer 2H-MoS_2 affecting optical absorption and subsequent mechanical response of the nanocomposite. The unique photomechanical response in 2H-MoS_2 based nanocomposites is a result of the rich d electron physics not available to nanocomposites based on sp~2 bonded graphene and carbon nanotubes, as well as nanocomposite based on metallic nanoparticles. The reversible strain dependent optical absorption suggest applications in broad range of energy conversion technologies.