These robot fingertips mimic the nerve signals of a human hand

By Alex Hughes

Published: Wednesday, 06 April 2022 at 12:00 am

Accurately replicating touch in robots can be tricky, but by using a 3D printer, a team of researchers have created an accurate representation of human fingertips in a robot hand.

The research was led by Nathan Lepora, a professor of robotics and AI from the University of Bristol. Working with his colleagues, Lepora created a sense of touch in an artificial fingertip.

“Our work helps uncover how the complex internal structure of human skin creates our human sense of touch,” said Lepora.

“This is an exciting development in the field of soft robotics – being able to 3D-print tactile skin could create robots that are more dexterous or significantly improve the performance of prosthetic hands by giving them an in-built sense of touch.”

This was done using a 3D-printed mesh of pin-like papillae (the bumps under your skin that form the ridges of a fingerprint). These artificial papillae are made using advanced 3D printers that can mix both soft and hard materials to create complicated structures.

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The robot fingertip © University of Bristol

“We found our 3D-printed tactile fingertip can produce artificial nerve signals that look like recordings from real, tactile neurons. Human tactile nerves transmit signals from various nerve endings called mechanoreceptors, which can signal the pressure and shape of a contact.”

A study back in 1981 first plotted electrical recordings from the nerves in human fingertips. Lepora and his team of researchers tested their 3D-printed fingertip against the findings of this original study, using the same ridged shapes, and discovered a very close match to the data of a human hand.

“For me, the most exciting moment was when we looked at our artificial nerve recordings from the 3D-printed fingertip and they looked like the real recordings from over 40 years ago! Those recordings are very complex with hills and dips over edges and ridges, and we saw the same pattern in our artificial tactile data.”

While the research has created a very close resemblance to a human fingertip and the nerves underneath, it was not as sensitive to fine details. The team believes this is because the 3D-printed skin is thicker than human skin.

This research could lead to a better replication of human hands. Most specifically, an improved dexterity in robots, able to better grip objects, and understand the shapes that they are touching. Lepora and his team are now looking to the future, aiming to make this new artificial skin as good as, or even better, than human skin.

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