A Light-Activated Explosive Micropropeller

Abstract

Self-propelled micro/nanomotors possess tremendous exciting promise in diverse fields. We describe an asymmetric, fuel-free and near-infrared light-powered torpedo micromotor, which is constructed by using a porous membrane-assisted layer-by-layer sol-gel method to form silica multilayer inside the pores, following by the deposition of gold nanoparticles on one end of the pores. In the absence of chemical fuels, the high propulsion of microtorpedoes under illumination of near-infrared light is owing to the photo-thermal effect of gold clusters, generating a thermal gradient inside the microtorpedoes. The speed of microtorpedoes is dependent on the laser powers and media. More interestingly, such fuel free-powered microtorpedoes could explode triggered by higher laser power at the predefined site and thus provide a new platform for future biomedical applications.

Near infrared-light responsive WS2microengines with high-performance electro- and photo-catalytic activities

“…Up to now, UV and visible light-triggered micromotors have been extensively studied for photodegradation processes, [35][36][37] with NIR light only used for enhanced propulsion and triggered drug release schemes. 38,39 Unlike such early efforts, the new micromotors described here hold considerable promise for the utilization of solar light for a myriad of renewable energy utilization schemes. Fig.…”

Light-Powered Micro/Nanomotors

“…However, the movement behavior of such a rocket is not stable. To solve this problem, He’s group fabricated a near-infrared-light-powered torpedo micromotor by the layer-by-layer sol-gel method, which performs stable movement in a straight line in various media [ 94 ]. In consideration of the manufacturing of light-powered MNMs, the LbL assembly method has the advantages of mass production and a convenient operation process.…”

Geometry Design, Principles and Assembly of Micromotors

“…Figure 4 d demonstrated light-control over the propulsion of microbubble-driven Ti/Cr/Pt catalytic microengines, where hydrogen peroxide fuel is degraded under local illumination of Si/Pt substrate [ 127 ]. Light powered/controlled motion can be related to several categories by using (i) semiconductor photocatalytic [ 161 , 162 , 163 , 164 , 165 , 166 , 167 ]; (ii) metallic plasmonic [ 168 , 169 ]; (iii) phototactic [ 170 , 171 ]; (iv) hybrid semiconductor-metallic swimmers [ 172 , 173 , 174 , 175 , 176 , 177 ]; (v) thermophoresis [ 178 , 179 , 180 ] and (vi) thermocapillary effects [ 181 ]. Other light controlled motors include: dual-light controlled [ 182 ] and a spectrally tunable light-driven silicon nanowires [ 183 ].…”