Carnegie Mellon University engineers have developed a soft material with metal-like conductivity and self-healing properties, and it is the first material to maintain sufficient electrical adhesion to support digital electronics and actuators. This progress has been published in Nature’s electronicsrepresents a breakthrough in softbotics, robotics, electronics and medicine fields.
At Carnegie Mellon University, softbotics represent a new generation of soft machines and robots manufactured from multifunctional materials that combine sensing, actuation, and intelligence.
The research team presented the material, which is a liquid metal-infused organic composite with high electrical conductivity, low hardness, high stretchability, and self-healing properties in three applications:
- A damage-resistant robot inspired by a snail
- Standard circuit for operating a toy car
- Reconfigurable bioelectrode for measuring muscle activity at different sites in the body
“This is the first soft material that can maintain electrical conductivity high enough to support power-hungry digital electronics and devices,” said lead author Carmel Magidi, professor of mechanical engineering. “We’ve proven that you can actually start engines with it.”
The fully untethered snail robot used a self-healing conductive material on its smooth outer surface, which was embedded with a battery and electric motor to control the motion. During the demonstration, the team cut the conductive material and watched its speed decrease by more than 50%. Due to its self-healing properties, upon manually rewiring the material, the robot re-wired it electrically and regained 68% of its original speed.
The material can also serve as a modular building block for reconfigurable circuits. In the demo, a single piece of gel initially attached the toy car to a motor. When the team split this gel into three sections and attached one section to a roof-mounted LED, they were able to restore the car’s connection to the engine using the remaining two sections.
“In practice, there will be cases where you want to reuse these jelly-like electronics and recycle them into different configurations, and our toy car demonstration shows that’s possible,” Magdy explained.
Finally, the team demonstrated the ability of the material to be reconfigured to obtain electromyography (EMG) readings from different locations in the body. Due to its modular design, the musculature for measuring hand activity can be reattachable to the anterior muscles of the forearm and the back of the leg for measuring calf activity. This opens doors to electronic tissue interfaces such as EMGs and EKGs using soft, reusable materials.
“Softbotics is about seamlessly integrating robots into everyday life, putting humans at the center,” Magdy explained. “Instead of wires to biomonitoring electrodes that connect patients to biometric devices mounted on a cart, our gel can be used as a bioelectrode that interacts directly with body-mounted electronic devices that can collect and transmit information wirelessly.”
Going forward, Majidi hopes to couple this work on artificial nerve tissue with his research on artificial muscles to build robots made entirely of soft, gel-like materials.
“It would be interesting to see soft-bodied robots used to monitor hard-to-reach places. Whether it’s a snail that can monitor water quality, or a slug that can crawl around our homes looking for mold.”
video: https://youtu.be/E4nBsJGkK7Y
