Graphene and silly putty combined into super-sensitive strain sensors
After 73 years of not being truck tires, silly putty is getting an upgrade. You still won’t be driving on the stretchy, bouncy polymer, but it might end up improving your health, thanks to a new ingredient in the mix. By mixing graphene into a viscous, silicone polymer (which, technically isn’t Silly Putty™, instead being labeled G-putty,) researchers have been able to transform the toy into an extremely sensitive strain sensor. This allows for measurements of tiny physical movements, such as your pulse moving along your carotid artery.
So how do these two great things work so well together? The putty is usually made from a mix of silicon and borax, and has long polymer chains that, among other things, make it flexible but very elastic. With a bit of pressure, you can easily deform it without damaging the bonds that hold it together. That pressure comes into play with the graphene. Among graphene’s list of exciting abilities is that the one-atom-thick sheets of carbon can conduct electricity. In this case, researchers are taking advantage of how that conductivity changes when the graphene is bent even a tiny amount. Putting the graphene into the putty then created a flexible, durable tool that could pick up shifts in pressure as tiny as a spider’s footstep.
As cool as it sounds, researchers weren’t actually looking to track spiders with this project. They were attracted to the fact that the graphene-infused G-putty was 250 times more sensitive than common strain censors while also being moldable and relatively inexpensive. The putty could then be placed on a person’s chest to measure how much their ribs expand with each breath to monitor breathing, or monitor your pulse when placed on your neck. It could easily replace blood pressure arm cuffs, offering an affordable, unobtrusive and… bouncier? upgrade to common medical devices.
Source: Supercharged silly putty can detect spider footstep by Rachael Lallensack, ScienceShots