Photogated humidity-driven motility.

ABSTRACT: Hygroinduced motion is a fundamental process of energy conversion that is essential for applications that require contactless actuation in response to the day-night rhythm of atmospheric humidity. Here we demonstrate that mechanical bistability caused by rapid and anisotropic adsorption and desorption of water vapour by a flexible dynamic element that harnesses the chemical potential across very small humidity gradients for perpetual motion can be effectively modulated with light. A mechanically robust material capable of rapid exchange of water with the surroundings is prepared that undergoes swift locomotion in effect to periodic shape reconfiguration with turnover frequency of <150?min(-1). The element can lift objects ?85 times heavier and can transport cargos ?20 times heavier than itself. Having an azobenzene-containing conjugate as a photoactive dopant, this entirely humidity-driven self-actuation can be controlled remotely with ultraviolet light, thus setting a platform for next-generation smart biomimetic hybrids.

SUBMITTER: Zhang L 

PROVIDER: S-EPMC4490392 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature