Fig. 6: Light-gated redox patterning of BTX-gel in aqueous Fe(ClO4)3 with UV light enables high spatio-temporal control over local oxidation of the gel and associated changes in color, fluorescence and swelling.
From: Light-gated redox switching and actuation in polymer hydrogels
a Patterning of a windmill onto a piece of freestanding BTX-gel. “Windmill” icon by Hey Rabbit from Noun Project CC BY 3.0. b Schematic representation and (c) 3D profile of reversible surface texture patterning of a substrate-confined BTX-gel. Irradiation was carried out for ~30 min to ensure full conversion and the largest extent of swelling. However, in principle, any intermediate swelling state can be accessed by shorter irradiation duration.
