New stretchable electronics for soft robots to allow embedded computation

The upcoming generation of robots may have the ability to blend in perfectly with their surroundings, moving smoothly and naturally. This vision is expected to soon become a reality, thanks to advancements in soft robotics.

For this, soft robots need stretchable electronics to perform complex tasks. However, the current methods have limitations: rigid computers are not suitable for stretchable soft robots.

Yale University’s Stephanie Woodman and her colleagues have developed a method to create stretchable versions of complex circuits.

This method allows for the integration of circuit boards and other such things into soft robots without sacrificing their flexibility and durability.

“We present a generalized method to translate any complex two-layer circuit into a soft, stretchable form,” the researchers wrote in the study paper.

The new method

Existing alternatives to rigid computers often have limited computational power and become less conductive when stretched. This makes them unsuitable for many applications.

The researchers have adapted traditional Arduino boards, making them flexible and adaptable to the needs of soft robots. Arduinos are open-source microcontroller boards .

The team noted in the press release: “Arduino could control and sense robotic movements, suggesting that they could help advance processing abilities in soft robots and wearable devices.”

In their search for alternatives, the team thoroughly investigated the electromechanical properties of oxidized gallium-indium (OGaIn).

As per the press release , OGaIn is “a conductor with both solid and liquid components.”

Moreover, they optimized a manufacturing process that could be easily scaled up.

The laser cutting and stencil printing techniques were used to create flexible circuit boards with OGaIn.

To demonstrate the method’s validity, the researchers created stretchable versions of commercially available devices, including the Arduino Pro Mini, Arduino Lilypad, Sparkfun Sound Detector, and Sparkfun RGB and Gesture Sensor.

Shows promise in testing

Interestingly, newly created flexible boards remained operational despite extreme stretching.

This method allows for the integration of microcontrollers and single-board computers into soft robots .

The team embedded highly stretchable Arduino boards into different soft robot bodies. These stretchable Arduino boards can control and sense robotic movements, providing the computational power necessary for advanced applications.

“As demonstrations of the method’s utility, we embedded highly stretchable (>300% strain) Arduino Pro Minis into the bodies of multiple soft robots,” the study noted.

Interestingly, the soft Arduinos demonstrated remarkable performance even under extreme conditions, successfully controlling robot movement, sensing human actions, and detecting contact with other machines.

The scientists specifically inserted it into areas of a crawling robot that were subjected to significant strain. Furthermore, soft Arduinos implanted in smart garments might detect and report touch with other robots, as well as sense a user’s arm motions.

“We hope this work will enable further research into soft systems endowed with computational intelligence rivaling today’s rigid systems without sacrificing compliance, thus facilitating the realization of soft robots that can sense, decide, act, and adapt in the real world,” the authors write.

The findings were published in the journal Science Robotics.