Google is in the process of bringing out "electronic tattoo," which could help you measure your heart rate, nutritional status, body temperature, hydration and breathing rate.
First of all they are not tattoos, as there's no ink, needles or piercing of the skin.
The reason that they are called "tattoos" is because their application is similar to those in kid's fake tattoos. These so-called tattoos usually start out on a sheet of plastic, is then applied to the skin and rubbed on from outside the plastic, then the plastic is peeled away, leaving only a very thin, rubber patch that has a layer of flexible silicon wires.
The idea behind the tattoo is to create an electronic device that usually involving sensors, which is thinner than a sheet of paper and is as flexible as a Band-Aid.
According to the researchers, these tattoos attached to the chest of a patient or even a newborn will monitor a wide range of vital signs including heart rate, nutritional status, body temperature, hydration and breathing rate.
Google , for example, has specific patents for an electronic tattoo which functions as a lie detector.