Fig. 2
From: Epidermal Differential Impedance Sensor for Conformal Skin Hydration Monitoring
Epidermal, differential hydration sensor systems mounted on the skin of the forearm. This sequence of images shows the device, undeformed (a), and uniaxially stretched along the horizontal (b), vertical (c), diagonal right (d) and diagonal left (e) directions. Here, the device adheres to the skin by van der Waals interactions alone, thereby allowing it to be easily peeled from the skin using tweezers (f)