Touchy subject: 3D printed fingertip 'feels' like human skin
Bristol scientists put finger on key to improving robot dexterity and performance of prosthetic hands
Date:
April 6, 2022
Source:
University of Bristol
Summary:
A highly sensitive, 3D-printed fingertip could help robots become
more dexterous and improve the performance of prosthetic hands by
giving them an in-built sense of touch.
FULL STORY ========================================================================== Machines can beat the world's best chess player, but they cannot handle
a chess piece as well as an infant. This lack of robot dexterity is
partly because artificial grippers lack the fine tactile sense of the
human fingertip, which is used to guide our hands as we pick up and
handle 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 & AI (Artificial Intelligence), Nathan Lepora,
from the University of Bristol's Department of Engineering Maths 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 robots that are more dexterous or significantly improve
the performance of prosthetic hands by giving them an in-built 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-like papillae on the underside of the compliant skin, which mimic the dermal papillae found
between the outer epidermal and inner dermal layers of human tactile
skin. The papillae are made on advanced 3D-printers that can mix soft
and hard materials to create complicated structures like those found
in biology.
"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. Classic work by Phillips and Johnson in 1981 first
plotted electrical recordings from these nerves to study 'tactile
spatial resolution' using a set of standard ridged shapes used by psychologists. In our work, we tested our 3D-printed artificial fingertip
as it 'felt' those same ridged shapes and discovered a startlingly
close match to the neural data," said Professor Lepora "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," said Professor Lepora.
While 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 the 3D-printed skin is thicker
than real skin and his team is now exploring how to 3D-print structures
on the microscopic scale of human skin.
"Our aim is to make artificial skin as good -- or even better -- than
real skin," said Professor Lepora.
========================================================================== Story Source: Materials provided by University_of_Bristol. Note: Content
may be edited for style and length.
========================================================================== Related Multimedia:
* Robotic_hand_with_a_3D-printed_tactile_fingertips ========================================================================== Journal References:
1. Nicholas Pestell, Thom Griffith, Nathan F. Lepora. Artificial
SA-I and
RA-I afferents for tactile sensing of ridges and gratings. Journal
of The Royal Society Interface, 2022; 19 (189) DOI:
10.1098/rsif.2021.0822
2. Nicholas Pestell, Nathan F. Lepora. Artificial SA-I, RA-I and RA-II/
vibrotactile afferents for tactile sensing of texture. Journal
of The Royal Society Interface, 2022; 19 (189) DOI:
10.1098/rsif.2021.0603 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/04/220406101749.htm
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