Figure 3.

(A) Optical micrographs of the helical microgel in one cycle of actuation (80 ms on and 12 ms off). Laser irradiation starts at t = 0. Scale bar: 15 μm. (B) Radius of a right-handed helix (R) as a function of the irradiation duration. Left panel: recovery upon cooling after a light pulse of 80 ms. Irradiation was performed at 808 nm at an intensity of 1.7 W/mm² (see SI). The light intensity was enough to revert the chiral structure within 30 ms. The extra irradiation time (50 ms) effected recoiling to a left-handed (L) helix. The recovery process upon cooling takes place in a time interval of one tenth compared to the irradiation-driven helix inversion.