Tattoos you can turn on and off

Researchers have developed a new type of tattoo that can change color in response to electrical signals. The tattoos, made of tiny particles called quantum dots, can be turned on and off using a small device that emits a low-frequency electrical current. This technology has the potential to revolutionize the tattoo industry and could be used to create tattoos that display real-time data, such as heart rate, blood oxygen levels, or other vital signs. The tattoos are made by injecting the quantum dots into the skin, and the device is worn on the wrist like a smartwatch.