High-tech ‘skins’ turn everyday objects into robots

A new type of soft robot gets its power from the skin it’s in.

Robotic skin that bends, stretches and contracts can wrap around inanimate objects like stuffed animals, foam tubes or balloons to create flexible, lightweight robots. Removable, reusable sheets of this artificial skin, described online September 19 in Science Robotics, could also be used to build grippers or wearable devices.

“It’s an interesting approach,” says Christopher Atkeson, a roboticist at Carnegie Mellon University in Pittsburgh who wasn’t involved in the work. In some cases, it may be simpler to use a soft robot ready-made for a specific purpose, like squeezing through tight spaces (SN Online: 7/19/17) or gently grabbing objects (SN: 9/16/17, p. 8). But robotic skins could come in handy for search-and-rescue operations or space exploration — missions where a user might not know in advance what kind of robotic helpers they’ll need, but where packing light is key, Atkeson says.

Each piece of robotic skin is composed of elastic polymer or fabric, embedded with either air pouches that inflate when pumped full of gas or with nickel titanium coils that contract when heated by electric current. These gas pouches and coils allow the robotic skin to move and change shape.

Rebecca Kramer-Bottiglio, an engineer at Yale University, and colleagues used the skin to build several robots. The researchers achieved different types of motion by altering the layout of air pouches or coils in the skin and by attaching pieces of skin to an object in various configurations.

For instance, wrapping the skin around foam tubes in different orientations created robots that either scooted like inchworms or paddled forward on two ends. Patches of robotic skin around three foam fingers animated a soft robot grabber.

The researchers also fastened robotic skin to a shirt to create a garment that monitors posture. Whenever the skin sensed the user’s shoulders slumping, it wriggled gently to remind the wearer to sit up. Robotic skin could also be used in clothing to give the wearer a massage or provide tactile feedback in virtual reality, Atkeson says (SN Online: 4/6/18).

The robotic skin isn’t ready for off-the-shelf use just yet. To work, each piece must be tethered to hoses or wires feeding into its gas pouches or electric coils. But future versions could include portable air pressure and electricity devices, Kramer-Bottiglio says.