Your next heart monitor could be graphene-coated Silly Putty
 

For a child's toy, Silly Putty has some downright crazy physical properties. The mixture of boric acid and silicon oil, originally developed as a synthetic replacement for rubber, is a non-Newtonian fluid. Its viscosity isn't affected by temperature,...

https://www.engadget.com/2016/12/11/...d-silly-putty/