RALEIGH, NC—Engineers at North Carolina State University have developed a robotic gripper that is gentle enough to pick up a drop of water, strong enough to pick up a 14-pound weight, dexterous enough to fold a cloth, and precise enough to pick up strips of film that are 20 times thinner than a human hair.
In addition to possible manufacturing applications, the gripper is embedded with technology that allows it to be controlled by the electrical signals produced by forearm muscles, demonstrating its potential for use with robotic prosthetics.
“It is difficult to develop a single, soft gripper that is capable of handling ultrasoft, ultrathin and heavy objects, due to tradeoffs between strength, precision and gentleness,” says Jie Yin, Ph.D., an associate professor of mechanical and aerospace engineering at NC State. “Our design achieves an excellent balance of these characteristics.”
The new gripper builds on an earlier generation of flexible, robotic devices that drew on the art of kirigami, which involves both cutting and folding two-dimensional sheets of material to form three-dimensional shapes.
The new design is able to achieve high degrees of strength and gentleness because of how it distributes force throughout the structure of the gripper.
“The strength of robotic grippers is generally measured in payload-to-weight ratio,” explains Yin. “Our grippers weigh 0.4 gram and can lift up to 6.4 kilograms. That’s a payload-to-weight ratio of about 16,000.
“That is 2.5 times higher than the previous record for payload-to-weight ratio, which was 6,400,” claims Yin. “Combined with its characteristics of gentleness and precision, the strength of the gripper suggests a wide variety of applications.”