Figure 13.

Human motion detection. (a) Electrical signal response of the bilayer composite hydrogel strain sensor with arm bending. (b) The relative current of the strain sensor changes with the wrist moving in two directions. (c) The piezoresistive response of the strain sensor when nodding. (d) The electrical signal of the strain sensor response with finger bending at 45° and 60°. (e) The relative resistance changes of the strain sensor when the mouth is opening. (f) Current response curves for smiling. Reproduced from [134], with permission from Elsevier, 2022.