Most advanced artificial touch for brain-controlled bionic hand
Scientists from the US-based Cortical Bionics Research Group have developed an innovative method to encode natural hand sensations. By employing microstimulation patterns in brain-implanted electrodes, individuals with spinal cord injuries can control a bionic arm and experience tactile sensations such as edges, shapes, and motion - capabilities previously unattainable.
"In this work, for the first time the research went beyond anything that has been done before in the field of brain-computer interfaces (BCI) - we conveyed tactile sensations related to orientation, curvature, motion and 3D shapes for a participant using a brain-controlled bionic limb. We are in another level of artificial touch now. We think this richness is crucial for achieving the level of dexterity, manipulation, and a highly dimensional tactile experience typical of the human hand," said Giacomo Valle, lead author of the study and Assistant Professor at Chalmers University of Technology in Sweden.
The importance of touch
A sense of touch is vital for autonomy and quality of life. For those with spinal cord injuries, tactile sensations are disrupted as electrical signals between the hand and brain are blocked. While bionic limbs controlled by brain signals can restore some functionality, their lack of sensory feedback makes it difficult to handle objects effectively. This research aims to improve usability by enabling a sense of touch in extracorporeal bionic limbs.
Technology enabling brain-controlled bionic limbs
The study involved two participants with brain implants in sensory and motor regions responsible for hand and arm control. Over several years, researchers recorded and decoded electrical activity linked to motor intentions. By interpreting these brain signals, participants could control a bionic arm directly with their thoughts.
Complex touch sensation typed into the brain
Through advanced microstimulation techniques, researchers "typed" tactile sensations directly into the participants' brains. "We found a way to type these 'tactile messages' via microstimulation using the tiny electrodes in the brain and we found a unique way to encode complex sensations. This allowed for more vivid sensory feedback and experience while using a bionic hand," explained Valle.Participants reported feeling object edges and motion across their fingertips. The brain-computer interface (BCI) translated motor intentions into precise bionic arm movements. Sensors on the bionic limb transmitted contact information to the brain, enabling tasks like object manipulation with greater accuracy and control.
Future prospects for neural prosthetics
This research represents a critical step toward enabling individuals with spinal cord injuries to regain a complex sense of touch. Future developments will require advanced sensors and prosthetic technologies, including artificial skin, to expand the repertoire of tactile sensations. Implant technology will also need refinement to deliver a wider range of sensory feedback.
Research Report:Tactile edges and motion via patterned microstimulation of the human somatosensory cortex
