Researchers from Trinity College in Ireland developed wearable sensors by coating simple rubber bands with graphene. The idea is that the rubber band changes its electric conductivity when it stretches - so even tiny movements (such as breathing or pulse) can be sensed. Such sensors can also be used in the automotive industry, robotics, medical devices and more.
The researchers say that their method is simple and compatible with normal manufacturing techniques. The basic material (rubber) is very cheap of course.