'Gentle Bot' brings a human touch to robotics

Robots of the future may have a more human touch, thanks to researchers at Cornell University. 

In a recent paper published in the journal Science Robotics, robotics engineers outlined their latest invention: a soft robot hand, known as the "Gentle Bot," that is able to not only touch fragile items, but also to sense the shape and texture of the things it comes it contact with. 

"Our human hand is not functioning using motors to drive each of the joints; our human hand is soft with a lot of sensors ... on the surface and inside the hand," Huichan Zhao, a doctoral candidate in mechanical engineering at Cornell who is the lead author of the research article about the new soft robot hand, told NPR. "Soft robotics provides a chance to make a soft hand that is more close to a human hand."

Soft robotic technology is already used in warehouses to handle food and similar products, but the hand developed at Cornell has the potential to handle more delicate items than ever before. The technology, if developed further, could allow robots to directly interact with humans, or to squeeze into tight spaces. It could also make for better prosthetics. 

In the past, in order for a robotic hand to be able to sense what it was touching, the item would need to be made of a material that could conduct electricity. With the Gentle Bot, items just need to be able to conduct light. As Alyssa Danigelis explains for Seeker: 

Stretchy optical waveguides containing LEDs are built right into the pneumatic fingers, allowing them to "sense" the surroundings. When the soft fingers mounted on a rigid palm flex, even a tiny bit, that affects how much the light goes into the device. Those changes are measured by a light detector, or photodiode. The internal optical cords act kind of like nerves.

"Most robots today have sensors on the outside of the body that detect things from the surface," Zhao explained in a university press release. "Our sensors are integrated within the body, so they can actually detect forces being transmitted through the thickness of the robot, a lot like we and all organisms do when we feel pain, for example." 

Another advantage of the Gentle Bot: the cost. Robotic hands that rely on light signals rather than electricity can be made with cheaper materials, which could eventually lead to cheaper prosthetics, the Cornell researchers say. 

To test the Gentle Bot, the team placed three tomatoes in front of it and directed it to pick out the ripest. Other tests included picking up a ripe tomato without crushing it, and shaking a human hand. It was unable, however, to tell the difference between a real, unripe tomato and an acrylic one. 

"Time will tell if the robots that can farm our food will go on to snag our best produce at the farmer’s market — and with farming getting steadily more mechanized over the years, it’s not unlikely," speculated Samantha Cole for Vice's Motherboard.

As the field of soft robotics grows, a number of researchers have begun to experiment with ways to use the technology to directly assist people as well. In Italy, engineers are using soft robotics to develop a better endoscope to travel inside human bodies, physical models of vocal cords and lungs of preterm babies to be used to train doctors, and a soft arm that helps elderly people take a shower on their own. 

"There's a tremendous unmet need here," Joshua Lessing, director of research and development at the company Soft Robotics, told NPR.