If you build a soft, conformable robot body but then put rigid, unyielding actuators inside of it, you're kind of defeating the whole purpose of the thing. With that in mind, Korean scientists have created pliable artificial muscles for use in soft robotics.
Led by Prof. Il-Kwon Oh, researchers at the Korea Advanced Institute of Science and Technology (KAIST) started with one particular type of a two-dimensional, highly electrically-conductive material known as MXene.
When it was initially applied to one side of a thin strip of flexible polymer, it caused that strip to bend when an electrical current was applied. Unfortunately, though, because the MXene itself isn't very flexible, bits of it flaked off of the polymer every time it bent.
To remedy that problem, the scientists utilized an "ionic crosslinking" process to bond the MXene into the polymer. Strips of the resulting composite material bend quickly in response to even relatively low voltage, staying intact and maintaining their strength and conductivity after more than five hours of continuous movement.
So far, the technology has been demonstrated in the form of a narcissus-flower-like brooch that opens its petals in response to an electrical current, and robotic butterflies (shown in the video below) that move their wings up and down.
"Wearable robotics and kinetic art demonstrate how robotic muscles can have fun and beautiful applications," says Oh. "It also shows the enormous potential for small, artificial muscles for a variety of uses, such as haptic feedback systems and active biomedical devices."
A paper on the research was recently published in the journal Science Robotics.
Source: KAIST