Fig. 5.

Sensing performance of hydrogel #4: a Nyquist plot of hydrogel #4 and hydrogel #4 without NaCl, and conductivity of hydrogel #4 and hydrogel #4 without NaCl. b Strain–sensitivity curve and GF. c Response curve for stretching and returning. d 10,000 cycle tests at a strain of 10% with an enlarged graph showing the last 20 cycles. e Heptagonal performance graph comparing the hydrogel #4 to previously reported hydrogels. Applications of the hydrogel sensor for the movement of the f window, g finger, h knee, and i vocalization