Applying electricity for a few seconds to a soft material, such as a slice of raw tomato or chicken, can strongly bond it to a hard object, such as a graphite slab, without any tape or glue, a new study finds. This unexpected effect is also reversible—switching the direction of the electric current often easily separates the materials, scientists at the University of Maryland say. Potential applications for such “electroadhesion,” which can even work underwater, may include improved biomedical implants and biologically inspired robots.
“It is surprising that this effect was not discovered earlier,” says Srinivasa Raghavan, a professor of chemical and biomolecular engineering at the University of Maryland. “This is a discovery that could have been made pretty much since we’ve had batteries.”
In nature, soft materials such as living tissues are often bonded to hard objects such as bones. Previous research explored chemical ways to accomplish this feat, such as with glues that mimic how mussels stick to rocks and boats. However, these bonds are usually irreversible.