By: Douglas Main
There are these sensors that are really thin sheets of meshlike silcicon that will stick to your skin like a tattoo. They are applied with a minimum of adhesive and for at least a couple of hours. These sensors are placed on the skin in order to measure the electrical activity of the heart, brain, and muscles. The sheets are still being developed and improved on. They can also be used for just about anything, this is what makes them such a cool invention.
http://www.popularmechanics.com/science/health/breakthroughs/new-electronic-sensors-stick-to-your-skin