April: 3D printed fingertip | News and features


A highly sensitive 3D-printed fingertip could help robots become more dexterous and improve the performance of prosthetic hands by giving them an integrated sense of touch.

Machines can beat the best chess player in the world, but they can’t handle a chess piece as well as a baby. This lack of robot dexterity is partly due to the fact that artificial grippers lack the fine tactile sense of the human fingertip, which is used to guide our hands when we pick up and manipulate objects.

Two papers published in the Journal of the Royal Society Interface give the first in-depth comparison of an artificial fingertip with neural recordings of the human sense of touch. The research was led by Professor of Robotics and AI (Artificial Intelligence), Nathan Lepora, from the University of Bristol’s Department of Mathematics Engineering and based at the Bristol Robotics Laboratory.

“Our work helps uncover how the complex internal structure of human skin creates our human sense of touch. This is an exciting development in the field of soft robotics – being able to 3D print tactile skin could create more dexterous robots or dramatically improve the performance of prosthetic hands by giving them a built-in sense of touch.” , said Professor Lepora. .

Professor Lepora and colleagues created the sense of touch in the artificial fingertip using a 3D printed mesh of pin-shaped papillae on the underside of conformal skin, which mimic dermal papillae found between the outer epidermal and inner dermal layers of human tactile skin. Papillae are made on advanced 3D printers that can mix soft and hard materials to create complex structures like those found in biology.

“We discovered that our 3D-printed tactile fingertip can produce artificial nerve signals that resemble recordings from real tactile neurons. Human touch nerves transmit signals from various nerve endings called mechanoreceptors, which can signal the pressure and shape of a touch. Classic work by Phillips and Johnson in 1981 first plotted electrical recordings of these nerves to study “tactile spatial resolution” using a set of standard striate shapes used by psychologists. In our work, we tested our 3D-printed artificial fingertip as it ‘felt’ these same ridged shapes and found a surprisingly close match to the neural data,” Prof Lepora said.

“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! These recordings are very complex with hills and dips at edges and ridges, and we saw the same pattern in our artificial touch data,” Professor Lepora said.

Although the research found a remarkably close match between the artificial fingertip and human nerve signals, it was not as sensitive to fine detail. Professor Lepora suspects this is because 3D printed skin is thicker than real skin and his team is now exploring how to 3D print microscale structures of human skin.

“Our goal is to make artificial skin as good – or even better – than real skin,” Professor Lepora said.


“Artificial SA-I, RA-I and RA-II/vibrotactile afferents for tactile texture sensing”, by Pestell, N. & Lepora, N. in Journal of the Royal Society Interface.

“SA-I and RA-I artificial afferents for tactile detection of peaks and grids”, by Pestell, N., Griffith, T. and Lepora, N. in Journal of the Royal Society Interface.

More information

The research was funded by the Leverhulme Trust on a Research Leadership Award: www.leverhulme.ac.uk

Tactile Robotics Group at the University of Bristol

Robots with a human-like sense of touch could transform our economy and society by performing physical tasks that people currently need to do. The Tactile Robotics Group brings together experts in robotics, neuroscience and biomimetics to build this future.

The artificial touch should be robust, precise and sophisticated. The group manufactures and develops new 3D printed touch sensors and hands, such as the 3D printed tactile fingertip (Tac Tip). The group writes the algorithms that make the robots work and applies computational neuroscience to these sensors and algorithms to mimic the way the brain processes tactile information. Find out more: https://www.bristol.ac.uk/engineering/research/tactile-robotics/

Professor Nathan Lepora is also responsible for tactile robotics at the Bristol Robotics Laboratory: https://www.bristolroboticslab.com/tactile-robotics

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