What do you get when you combine an all-time favorite children’s toy with a Nobel Prize-winning “wonder material”?
G-Putty – a new elastic sensory material capable of detecting the footsteps of a spider or a human pulse.
A research team led by scientist Jonathan Coleman at Trinity College Dublin, Ireland, and his colleagues discovered a way to combine the ubiquitous toy, Silly Putty with graphene – an electrically conductive, crystal-like formation that is one atom thick and derived from a block of graphite, according to the paper published Thursday in the journal Science.
Since two Russian-born scientists won a Nobel Prize for successfully isolating graphene in 2010, the nanomaterial has caught the imagination of the scientific community for its potential to yield a new generation of inventions, from electronic displays and solar panels, to lighter, stronger composite materials used in everything from bullet-proof vests to airliners and spacecraft.
The new G-Putty, the conductivity of which dramatically changes when it is squashed or stretched, opens up a further array of potential technological applications.
“If you touch it even with the slightest pressure or deformation, the electrical resistance will change significantly,” Dr. Coleman told Popular Science.
“Even if you stretch or compress the Silly Putty by one percent of its normal size, the electrical resistance will change by a factor of five. And that’s a huge change.”
The researchers added that G-Putty has sensitivity 500 times that of most existing strain sensors.
Coleman credits one of his graduate students, Conor Boland, with the idea to incorporate the graphene into Silly Putty after thinking, “ ‘Well, Silly Putty is a kids toy, but it’s really just a polymer, and a lot of people mix graphene with polymers—so why don’t we mix graphene with Silly Putty and see what happens?’ ”
Graphene alone was already a remarkable material.
The Monitor's Pete Spotts described it in 2010 as a "vanishingly thin material [that] is at least 100 times stronger than steel, conducts electricity more efficiently than copper, is highly flexible and the most transparent material known, and is remarkably efficient at conducting heat.”
Combined with the elastic properties of the Silly Putty, it may also have a range of medical applications, as it is capable of measuring a baby’s breath, as well as a person’s heart rate and even blood pressure.
To demonstrate the sensitivity of the new putty, Mr. Boland coaxed a spider to walk across it to measure its tiny footfalls – but it wasn’t easy.
“The real problem was that when a spider would put one foot onto the putty, it didn’t like the feel of it at all, so it would run the other direction,” Coleman told Popular Science. “It was very difficult to get a spider to stay on it long enough to generate the train of footsteps.”