Fig. 5
From: Skin color-specific and spectrally-selective naked-eye dosimetry of UVA, B and C radiations
Design and performance of skin-phototype-specific personalized UV sensors. The top panel shows a paper-based solar UV sensor prototype for a skin type V person in a wristband format after 100% MED exposure. Sensor design incorporates four paper disc-based smileys, each covered with different layers of TFF, and attached to a flexible wearable band. The smileys are initially invisible, but as the wearer is increasingly exposed to safe solar UVB thresholds of 25%, 50%, 75%, and 100% MED of that particular skin color, the smileys turn blue from left to right, respectively. The colored smileys correspond to total effective solar UV dose. This is demonstrated through assessing the performance of six customized sensors in simulated solar light (bottom six panels), assuring that sensors meet the wide-ranging UVB MED thresholds of people with different skin colors. The skin-phototype specificity is achieved by an appropriate combination of the smiley paper discs coated with different TFF layers (0–8) in a single sensor that allows dose-dependent modulation of sensor response
