Photothermally Actuated Microcantilever Beams Using Nanoparticles

Photothermally actuated microcantilever beams based on localized surface plasmons (LSPs) of nanoparticles (NPs) were used to modulate absorption efficiency. The bimaterial beams were composed of 200 nm thick poly(vinylpyrrolidone) (PVP) embedded with silver (Ag) NPs and 370 nm thick silicon nitride. NPs were designed to have a strong absorption at about 532 nm and convert the absorbed light energy to heat. The beams had a vertical deflection of 30 mum under the excitation of 532 nm green laser with an intensity of 500 W/cm². The corresponding mechanical and thermal response times were 0.27 ms and 10 ms, respectively.