Fabrication of Light-Driven Soft Actuators of Polymer/Ag Nanoparticles Embedded Metal-Organic Framework/Polymer Composite Thin Films

Abstract

Soft actuators are gaining attention as flexible components for soft robotics. Responsive materials that respond to external stimuli such as light are often used as the driving part of the soft actuator. For example, thermo-responsive soft actuators are fabricated by bilayer polymer films of different thermal expansion coefficients. Heating of such bilayer polymer films by plasmon heating enables the soft actuators to be driven remotely by light. In the present study, we report the fabrication of plasmonic heating driven responsive soft actuators by using metal-organic framework (MOF) thin films as supports of plasmonic nanoparticles. The thin films of Cu₂(bpydc)₂ (bpydc = 2,2’-bipyridine-5,5’-dicarboxylate) of which metal ion adsorption capacity is high were fabricated on Cu₂(bpdc)₂ (bpdc = 4,4’-biphenyldicarboxylate) which grown on ceramics precursor, Cu(OH)₂. The actuating was operated by plasmon heating of Ag nanoparticles contained in MOF thin films inserted in between the two polymers, PDMS (poly(dimethylsiloxane)) and PVDC (poly(vinylidene chloride)). Two polymers have different thermal expansion coefficient so that they work as soft actuators by plasmon heating. Such fabrication process of soft actuators would pave the way for development of advanced devices in the field of soft robotics.