Fig. 5

(a) Three-step inverse design process for determining the optimal length of an EAP hydrogel structure. Step 1: Experimental characterization of maximum deformation and Young’s modulus under fixed conditions (20 V, 90 s, 25 \(^{\circ }\)C). Step 2: Parameter identification of the GSF (\(c_g = 0.0484\)) based on measured data and sample geometry (25 \(\times\) 5 \(\times\) 10 mm). Step 3: With a target displacement of 16 mm and fixed width and thickness (5 mm and 10 mm), the optimal length of the EAP hydrogel was computed to be 33.3 mm. (b) The developed electrically actuated hydrogel gripper. The width of the finger holder is 32 mm and the length of the hydrogel is 33.3 mm. (c) The convergence of the design parameter EAP hydrogel length l and the cost function J(l) during the optimization process. (d) Deformation process of the designed electrically hydrogel soft gripper. Max displacement is defined as d.