Amit Lal, a professor of electrical engineering at Cornell University and one of the researchers behind the new technology said, “It literally goes into the air. Very little remnants of [the device] are left behind. Many scientists who have been able to see the material are hoping to be able to use transient electronics in a number of industries. For instance, the use of this material would be extremely efficient in the building of medical implants that would be able to vanish instead of requiring surgical removal.
Other uses for the technology could be in environmental sciences where if they appeared in sensors deposited in forests and oceans to measure pollution or carbon dioxide levels, would reduce the need for scientists to have to go back and retrieve the equipment. However, some have pointed out that while transient electronics leave little to no evidence of material behind, there is still a risk of remaining material that could possibly contaminate the devices surrounding area.
Previously, other researchers have reported designing transient electronics that would be able to use water or heat to initiate the self-destruction mode. However, by not having control of the elements that could lead the technology to vaporize, there are too many drawbacks to this approach. Therefore, Lal says the Cornell team aimed to create a transient technology that would allow for more control.
The design consists of a microchip embedded in a polycarbonate shell. Inside the shell are tiny cavities filled with metals such as rubidium and cesium. These metals react with oxygen, and are the key to destroying the chip. “You can effectively think of it as a self-triggered fuel,” Lal says. “Unlike gasoline, where you need a match to light it up, here you just expose it to air and it will instantaneously begin to react.”
Most of the time, the metals are barricaded behind membranes made from graphene and silicon nitride. To unleash them, the researchers send a radio signal to the chip. The chip then passes an electric current from its battery though the membrane. This warms the graphene up, making it expand until it cracks the silicon nitride. Then air can rush in and begin reacting with the metals. Heat from this chemical reaction pours into the plastic shell, breaking and finally vaporizing it.
As the shell cracks, it can shatter the microchip as well. “Once you heat this stuff up, there’s enough stress in it to break up the chip into tiny, tiny pieces,” Lal says. He’s also experimenting with chemicals that form hydrofluoric acid when heated to etch away at the chip.
In December, the team behind the revolutionizing technology was issued a patent and the team hopes to be able to deploy the technology soon.