Figure 1.

Materials and structures of the sweat‐activated battery (SAB). a) The 3D schematic illustration of a person wearing a flexible electronic device powered by the SAB for wireless sweat components monitoring. b). The exploded illustration of the SAB. c) Optical images of the top and bottom views of the SAB. d) Plots of discharge behaviors of the SAB with 20‐mL different saturated electrolytes, including KCl (red plot), ZnSO₄(green plot), and CaCl₂ (yellow plot). e). The scanning electron microscopy (SEM) images of the neat fabric and fabrics with CuSO₄, KCl.