Researchers from North Carolina State University have developed a wearable, wireless sensor that can monitor a person’s skin hydration for use in applications that need to detect dehydration before it poses a health problem. The device is lightweight, flexible and stretchable and has already been incorporated into prototype devices that can be worn on the wrist or as a chest patch. The wearable wristband and chest patch may be used for low-cost, wireless and continuous sensing of skin hydration and other health parameters. The sensor consists of two electrodes made of an elastic polymer composite that contains conductive silver nanowires. These electrodes monitor the electrical properties of the skin. Because the skin’s electric properties change in a predictable way based on an individual’s hydration, the readings from the electrodes can tell how hydrated the skin is.