Researchers have created a health sensor that can be put onto the skin, similar to a temporary tattoo, to measure vital signs such as pulse and blood pressure.
Deji Akinwande and Nanshu Lu from the University of Texas at Austin developed the tattoo, which is made of graphene to be flexible. It's also extremely thin, allowing it to move around as the skin stretches and compresses. It presents a novel, non-invasive way of monitoring vitals.
First, a one atom-thick layer of graphene is dropped onto a small sheet of copper. A stretchy base polymer is then coated onto the graphene and the copper is removed. The new sheet is then placed onto a dissolvable tattoo paper. The grapehene is then carved onto electrodes, and the flexibility of the electrodes allows the tattoo to mold to the bumps and ridges in the human skin. This very intimate contact removes the need for any adhesive material.
These measurements include signals from the heart, brain and muscles. It can also read skin temperature and hydration.