Temporary Tattoo pH Sensor with pH‐Responsive Hydrogel via Initiated Chemical Vapor Deposition

In the expanding field of physiological pH skin sensors, thin temporary tattoo‐based devices have gained attention because of ultra‐conformal adhesion while providing excellent water vapor transmission. Here, a pH sensor tattoo made of temporary tattoo paper, screen‐printed poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate electrodes, and pH‐responsive hydrogel deposited via initiated chemical vapor deposition, is proposed. The tattoo...