Fig. 6.

a Photograph of the e-skin containing strain sensors, temperature sensor and humidity sensor. b Photograph of the e-skin attached to the wrist. c Schematic illustration of wireless monitoring system of the e-skin. d Real-time response signals of wrist movement measured by the sensing unit and displayed on a phone. e Real-time response signals of skin deformation tested by the sensing unit and displayed on a phone. f Varieties in ambient temperature engendered by a cup with hot water near the temperature sensing unit and displayed on a phone. g Changes in ambient humidity caused by exhaling to the humidity sensing unit and displayed on a phone