Researchers devise tool to knit robotic wearables

1 min read

Scientists at MIT have created a tool to machine-knit soft pneumatic actuators, an important technology in some wearables.

Soft pneumatic actuators use compressed air to power motion and are used in a variety of applications including assistive wearables, robotics and rehabilitative technologies.

However, until now creating the devices has proved time-consuming since they require a manual design and fabrication pipeline, which results in a lot of trial and error cycles during test and development.

Now scientists from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have devised “a scalable pipeline to computationally design and digitally fabricate soft pneumatic actuators,” the institution said. The pipeline is called “PneuAct.” and uses an autonomous machine-knitting process to create the actuators.

MIT said: “A human designer simply specifies the stitch and sensor design patterns in software to program how the actuator will move, and it can then be simulated before printing.

“The textile piece is fabricated by the knitting machine, which can be fixed to an inexpensive, off-the-shelf rubber silicone tube to complete the actuator.”

The knitted actuator uses conductive yarn to allow it to "feel" what it touches. The MIT team have created several prototype actuators for applications including an assistive glove, a soft hand, an interactive robot, and a pneumatic walking quadruped.

The interactive robot was able to sense when it was touched and to react to that touch. While the assistive glove can be worn to supplement finger muscle movement, meaning it could be used by those with injury, limited mobility, or other trauma to the fingers.

“Digital machine knitting, which is a very common manufacturing method in today’s textile industry, enables ‘printing’ a design in one go, which makes it much more scalable,” says Yiyue Luo, MIT CSAIL PhD student and lead author of a new paper about the research.

“Soft pneumatic actuators are intrinsically compliant and flexible, and combined with intelligent materials, they’ve become a necessary force in many robots and assistive technologies — and rapid fabrication, with our design tool, can hopefully increase ease and ubiquity.”