Ordinarily, if you want to build a device that's highly electrically conductive, you have to use rigid metals. Now, however, scientists at Carnegie Mellon University have created a soft and flexible material that fits the bill.
Led by Prof. Carmel Majidi, the researchers started by suspending micrometer-sized flakes of silver within a polyacrylamide-alginate hydrogel.
When that material was subsequently partially dehydrated, the silver flakes linked with one another to form networks running throughout the hydrogel matrix. Not only were those networks very electrically conductive, but they were also able to withstand mechanical deformations – in other words, they remained conductive upon being stretched, compressed or bent.
Although other groups have previously tried developing conductive hydrogels, they typically had to choose between conductivity and deformability. The Carnegie Mellon hydrogel is claimed to be unique, in that it excels in both qualities.
It has already been used to create skin-mounted electrodes that stimulate the underlying muscles. Such devices could ultimately be of use to people with neuromuscular disorders. The gel has also been utilized to build a swimming soft-bodied robotic stingray – and the possibilities don't stop there.
"With its high electrical conductivity and high compliance or 'squishiness,' this new composite can have many applications in bioelectronics and beyond," says Majidi. "Examples include a sticker for the brain that has sensors for signal processing, a wearable energy generation device to power electronics, and stretchable displays."
A paper on the research was recently published in the journal Nature Electronics.
Source: Carnegie Mellon University