New breakthrough 3D printed fingertip feels and acts like human skin

Researchers have been working on robot dexterity for several years now trying to give the machines human-like sensitivity. This has been no easy task as even the most advanced machines struggle with this concept.

Now, Professor of Robotics & Artificial Intelligence, Nathan Lepora, from the University of Bristol’s Department of Engineering Maths and based at the Bristol Robotics Laboratory may have made a key breakthrough in this area, according to a statement released by the institution on Wednesday.

An exciting development in soft robotics

“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.

How did this ambitious team of researchers create a human-like sense of touch? Well, they drew inspiration from actual skin. They used a 3D-printed mesh of pin-like papillae on the underside of the compliant skin, which imitated the dermal papillae found between the outer epidermal and inner dermal layers of actual human skin. They then further used advanced 3D printers that can combine soft and hard materials to create the kind of structures only found in biological assets up to now.

Artificial nerve signals as good as the real thing

“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,” added Professor Lepora.

Now the team is working on making the artificial fingertip as sensitive to fine detail as the real thing. Currently, the 3D-printed skin is thicker than real skin which may be hindering this process. As such, Lepora's team is now working on 3D-printing structures on the microscopic scale of human skin.

“Our aim is to make artificial skin as good – or even better - than real skin,” concluded Professor Lepora. The end result could have many applications in soft robotics including in the Metaverse.