Light-Programmed Bistate Colloidal Actuation Based on Photothermal Active Plasmonic Substrate

Abstract

Active particles have been regarded as the key models to mimic and understand the complex systems of nature. Although chemical and field-powered active particles have received wide attentions, light-programmed actuation with long-range interaction and high throughput remains elusive. Here, we utilize photothermal active plasmonic substrate made of porous anodic aluminum oxide filled with Au nanoparticles and poly( N -isopropylacrylamide) (PNIPAM) to optically oscillate silica beads with robust reversibility. The thermal gradient generated by the laser beam incurs the phase change of PNIPAM, producing gradient of surface forces and large volume changes within the complex system. The dynamic evolution of phase change and water diffusion in PNIPAM films result in bistate locomotion of silica beads, which can be programmed by modulating the laser beam. This light-programmed bistate colloidal actuation provides promising opportunity to control and mimic the natural complex systems.

In Situ Nanomechanics: Opportunities Based on Superplastic Nanomolding

“…One typical system is nanorods made of hydrogels, which can aggregate and trap particles under the driving of capillary forces . Combined with plasmonic nanoparticles, photothermal responsive soft actuators can be established which present large force output and fast mechanical response. − Likewise, doping the hydrogel nanorods with magnetic nanoparticles can make cilia like motion, which can be used for droplet transport on the surface . Another prominent device based on 1D nanostructures and in situ nanomechanics is the nanoelectromechanical system (NEMS).…”

Photothermophoretic Splitting of Gold Nanoparticles for Plasmonic Nanopores and Nanonets Sensing

“…One typical approach for optically modulated plasmons is to incorporate light-responsive materials in the plasmonic hot spots so that the plasmon resonances shift in response to light illumination. − One clear advantage is that the fast switching speed triggered by light makes such a plasmonic system highly compatible for the concept of optical circuits and computation. Another type of optically tunable plasmons is based on the photothermal deformation of plasmonic components, which alters their color appearance.…”