Scientific American:

A dash of graphene can transform the stretchy goo known as Silly Putty into a pressure sensor able to monitor a human pulse or even track the dainty steps of a small spider.

The material, dubbed G-putty, could be developed into a device that continuously monitors blood pressure, its inventors hope. It also demonstrates a form of self-repair that may herald smarter graphene composites.

Example number eighty gazillion of how cool science is.