Replicating the familiar sense of human touch is one of the most pressing challenges facing roboticists who are working on improving bionic limps. That problem may soon be solved, however, thanks to a team of researchers that has recently developed a new tactile sensing method that could augment robotic materials made out of soft materials.

So far, engineers have confronted the challenge of artificially replicating the complex biological mechanisms that make the sense of human touch by creating increasingly life-like bionic limbs with bionic soft materials, instead of the conventional, hard, and metallic structures of popular robots. But while soft material-based robotic hands offer impressive advantages in skin-like texture, they tend to lack the ability to collect a wide spectrum of sensory input.

In an effort to overcome this challenge, researchers at Beihang University in Beijing have developed a new sensing technique that involves soft material-based robotic fingers. The technique is centered around proprioception, a biological mechanism that enables mammals to perceive a degree of situational awareness, including position and movement, reports Interesting Engineering.

“The idea behind our recent paper is based on the proprioception framework found in humans, which is what determines our body position and load on our tendons/joints,” explains Chang Chen, one of the researchers.

Together with his colleagues, Chang came up with a prototype system that consists of a linear actuator, a strain sensor, a tendon (cable), and a soft robotic finger. Essentially, the system works by first capturing data from the sensor, and then employing machine learning tools to decode the rigidity and texture of an object or surface touched by the robotic finger.

In tests, the researchers were excited to find that the technique could read stiffness and texture with impressively high levels of accuracy, at 99.7 percent and 100 percent respectively. The findings represent a landmark breakthrough in the pursuit of human-like tactile sensation in bionic limbs, potentially changing the future of prosthetics.

Source study: arXiv: Tactile Sensing with a Tendon-Driven Soft Robotic Finger