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Photostimulus-responsive supramolecular actuators developed -- Exhibit reversible macroscopic deformations in both size and shape!

2012-12-12(Wed)

Under the leadership of HARADA Akira, Professor, Director, Project Research Center for Fundamental Sciences, Graduate School of Science, Osaka University, a group of researchers have developed a hydrogel actuator that bends, contracts, and expands in relation to the irradiation wavelength by integrating cyclodextrins (CD), cyclic oligosaccharides, and azobenzene (Azo), photoresponsive molecules, in hydrogels as sensors and control molecules. This hydrogel actuator achieves deformations in relation to the photic stimuli through a reversible link in host-guest interactions.
In a world first, this research group, through ultraviolet and visible light irradiation, controlled molecular recognition at the microlevel and achieved reversible macroscopic deformations of materials. This photostimulus-responsive elastic hydrogel actuator will be used in developing functional materials and materials for medical use.
This research was conducted as part of the JST's Core Research for Evolutionary Science and Technology (CREST).

Abstract

The development of stimulus-responsive polymeric materials is of great importance, especially for the development of remotely manipulated materials not in direct contact with an actuator. Here we design a photoresponsive supramolecular actuator by integrating host–guest interactions and photoswitching ability in a hydrogel. A photoresponsive supramolecular hydrogel with α-cyclodextrin as a host molecule and an azobenzene derivative as a photoresponsive guest molecule exhibits reversible macroscopic deformations in both size and shape when irradiated by ultraviolet light at 365 nm or visible light at 430 nm. The deformation of the supramolecular hydrogel depends on the incident direction. The selectivity of the incident direction allows plate-shaped hydrogels to bend in water. Irradiating with visible light immediately restores the deformed hydrogel. A light-driven supramolecular actuator with α-cyclodextrin and azobenzene stems from the formation and dissociation of an inclusion complex by ultraviolet or visible light irradiation.

 

 

 

 

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To learn more about this research, please read the full research report entitled "Expansion–contraction of photoresponsive artificial muscle regulated by host–guest interactions" on this page at the Nature Communications website.


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