More than a decade after losing his left hand in an accident, Dennis Aabo Sørensen has now been able to feel texture with a prosthetic fingertip. The technology that made this advance possible was developed by scientists at Sweden’s EPFL (Ecole polytechnique fédérale de Lausanne) and SSSA (Scuola Superiore Sant’Anna) in Italy. They described their research study in a paper that published in eLife this week.
Sørensen was able to feel texture using a bionic fingertip equipped with sensors called micro-electro-mechanical systems, which were embedded in silicon. When the artificial fingertip touches different textures, the sensors output electrical signals that travel through electrodes that were surgically implanted into his arm. His nerves receive the signals so he can feel in real-time whether an object he is touching is smooth or rough.
In an experiment to test the accuracy of the prosthetic fingertip, Sørensen correctly identified textures 96 percent of the time. Volunteers who were not amputees also tested the technology (using temporary electrodes instead of implants) and proved they could distinguish roughness in textures 77 percent of the time. This breakthrough should help accelerate the work that is being done by several research groups around the world to bring realistic sensing abilities to prostheses.
This study merges fundamental sciences and applied engineering: it provides additional evidence that research in neuroprosthetics can contribute to the neuroscience debate, specifically about the neuronal mechanisms of the human sense of touch. It will also be translated to other applications such as artificial touch in robotics for surgery, rescue, and manufacturing.