Fig. 6. (a) Digital photographs of the brightness of a LED bulb in response to the 50% strain change of the GA/SA₃ DN hydrogel, (b) relative resistance change of the GA/SA₃ DN hydrogel under different strains, (c) the relative resistance changes of GA/SA DN hydrogels as a function of strain, (d) their corresponding GF values, and (e) the response and relaxation times of GA/SA₃ DN hydrogel.