A Thermally Adjustable Multicolor Photochromic Hydrogel


  • Y.T. gratefully acknowledges financial support through a Grant-in-Aid for Scientific Research on Priority Areas (No. 417 and No. 438) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan. NIPA was kindly provided by KOHJIN Co., Ltd.


original image

A rainbow of possibilities: A porous polymer gel undergoes light-triggered rapid two-state switching between two arbitrary structural colors at a controlled temperature (see picture; “on”: upon UV irradiation, “off”: in the dark). This switching is attributed to a change between two volume states. As the temperature also contributes to the degree of swelling of the gel, the color of the gel can be tuned thermally over a wide range of wavelengths.