FIG. 1.

(a) A photograph of a prototype of the hydrogel-based microfluidic photoreactor with interdigitated branched channels. (b) Image of a typical pattern of dye infusion into the microfluidic hydrogel. (c) Subsequent image illustrating the photocatalytic degradation of the infused dye in the TiO₂ embedded hydrogel reactor. Reproduced with permission from Koo and Velev, J. Mater. Chem. A 1, 11106 (2013). Copyright 2013 Royal Society of Chemistry.¹⁸ (d) A schematic of hydrogel photovoltaics with microfluidic supply-replenishment network. The inset on the right displays the cross section view across the dotted yellow line. The red arrows indicate the lateral diffusive/convective transport between the source channels and drain channels. Reproduced with permission from Koo and Velev, Sci. Rep. 3, 2357 (2013). Copyright 2013 Nature Publishing Group.¹⁹