We’ve known for a long time that there’s a link between overexposure to ultraviolet (UV) light and skin cancer. The solution has been to cover up or lather on the sunscreen, but there are not many ways to easily measure your exposure to the radiation. Researchers at RMIT University in Australia have come up with a way to help. They have developed a new UV sensor.

The device is thin, flexible and can stretch. This means that it can be worn directly on exposed skin as a patch, or it can be incorporated into clothing such as a hat. It is made using a thin layer of zinc oxide — the same common and inexpensive material that is used in everything from baby lotions to sunblock to a pigment in paints. The material can also sense UV radiation, and the resulting sensors could eventually communicate with a smartphone or other device.

Interestingly, the same sensor design can be used to detect the presence of hydrogen or nitrogen dioxide (an atmospheric pollutant). The sensor technology is inexpensive to make and very durable, and so could have a number of applications for wearable Health Tech devices.