Gecko inspired reversible adhesion via quantum dots enabled photo-detachment

Inspired by the detachment behavior of gecko toe valgus, a reversible dry adhesive surface was developed, which is composed of polydimethylsiloxane (PDMS) micropillar arrays and MoO3-x quantum dots (MoO3-x QDs). The reversibility of adhesion is caused by the thermal expansion of the overall structure of the PDMS micropillar array due to the thermal response of MoO3-x QDs to external stimuli. Under infrared laser irradiation, the interface temperature of MoO3-x-PDMS surface increased from 20 C to 88.5 C in 60 s. The MoO3-x QDs-induced photothermal conversion facilitate the reduction of the real contact fraction between the bio-inspired micropillar arrays and the opposing/target surface, resulting in a significant decrease in adhesion. This work demonstrates a new strategy for realizing remote control of smart adhesives or surfaces. The mechanism elucidated in this work may find a broad application, such as in climbing robots, micro-manipulation/micro-selection in advanced manufacturing, active self-cleaning surface for solar panels, fibrillar dry adhesives and touch sensitive grippers in outer space explorations, and more.

Automated summary

A reversible dry adhesive surface has been developed, which reduces adhesion by inducing thermal expansion of the polydimethylsiloxane micropillar arrays. This work demonstrates a new strategy for realizing remote control of smart adhesives or surfaces, with potential applications in various fields.