Researchers Develop Electronic Skin for Soft Robots

A team of engineers from Seoul National University has developed a skin-like electronic system for soft robots to move with more flexibility, making them safer around humans.

Soft robotics is a subfield of robotics that aims to copy the way living organisms, such as human hands, move and adapt to their surroundings and tasks. Unlike traditional robots made of rigid materials, soft robots are made of flexible materials, which allow for increased flexibility and delicacy.

Soft robotics can assist not only in areas that require specifically manual labor, such as assisting the elderly, but also in areas that human hands cannot reach biologically, such as invasive surgery.

Still in its development phase, most soft robotic designs currently have soft bodies, but hard driving parts, such as rigid circuit boards. Their innately hard driving parts can frequently interfere with the robot’s motions.

But now the SNU team has developed electronic skins that makes a soft robot true to its name both from the inside and out.

“This e-skin opens a new avenue for soft robotic assembly,” Yongtaek Hong, a professor of electronic computer engineering at SNU and one of the lead researchers, said in a statement. “It is soft, thin, and light enough for a robot not to be perceptible, but it can activate the robot as ‘a driving skin.’ ”

The paper is published in Science Robotics.

The method

The e-skins use the wireless system to communicate. They can perform the four-state control signal at a distance of more than 5 meters and make communication noise-tolerant.

They also feature a spatially fragmented circuit configuration, allowing for flexibility.

In the video below, you can see how the e-skins allow the machine to stretch in different ways and go through tight spaces.  

Video: Soft Robotics Research Center, Seoul National University

Based on the print-friendly “stretchable hybrid electronics” approach, the e-skins work in two parts.

One part works with input sensing at a human side, and the other with activating soft robots.

The e-skins are thin, less than 1 mm, weigh in at around 0.8 g, and have a standard dimension of less than 1.5 mm × 1.5 mm, meaning they can be stretched and conformed like human skin.

Our motivation is to develop an electronic system that can be conformably attached on human skin or multi-curvature/arbitrary curved surfaces,” said Hong. “The electronic system would work as bio signal monitors, textile sensors, displays, soft robot controllers, etc.”

The next step

According to Hong, the researchers successfully tested that the e-skins can survive under mechanical deformation and be attached on soft robot frames to activate actuators without interfering with their soft motions.

Now, a soft robot can pass through and operate in highly confined spaces, sometimes smaller than the robot itself.

With the wireless communication, the researchers can wirelessly activate multiple types of soft robots through reversible assembly of e-skins.

The researchers are now working to build a feedback system with actuators and sensors to make soft robots move more efficiently.

We would like to combine sensors and actuators so that we can detect human body movement and the feedback signal can trigger the actuation of soft robot parts that will help human body movement,” said Hong.

The University Network