“…The stimulus could be light [12][13][14][15][16][17], sound [18], pH [14,19], host-guest interactions [20][21][22], charge separation [23], complexation [23], or oxidative/reductive reactions [24,25], etc., and it can also be a combination of some of them. This distinct character of physical gels promises accessibility for designing and constructing sensors, actuators, and other molecular devices [26,27].…”