Breakthrough SOFT ECoG™ technology published in Advanced Science
Mar 23, 2021

A new study led by Dr. Florian Fallegger (CTO of Neurosoft Bioelectronics) has been recently published in Advanced Science, highlighting the promising potential of our soft technology for the development of neural implants in clinical settings.

Neural implants can be used to diagnose and treat neurological disorders like epilepsy by electrically recording from the surface of the brain during surgery. However, the long-term success of current neural interfaces is limited by the mechanical mismatch between stiff electronics and soft living tissues.

The study, conducted at the Laboratory for Soft Bioelectronic Interfaces (LSBI) at EPFL and supported by the Wyss Center for Bio and Neuroengineering, has demonstrated MRI compatibility, good surgical handling and reliable recording of our soft electrode arrays that conform seamlessly to the nervous system.

At the LSBI, led by Prof. Stéphanie Lacour, advances in stretchable electronics have enabled the development of electrode grids optimized for human anatomy using thin silicone films. This material has the same mechanical properties as the dura mater, the membrane covering the brain, and thus can conform to its complex shape.

Working with clinicians at local hospitals, Prof. Jocelyne Bloch at CHUV (Lausanne) and Prof. Karl Schaller at HUG (Geneva), the LSBI team trialled the surgical handling of the soft electrode grids in human anatomy post-mortem. The clinicians found that the grids can be handled as well as existing devices while conforming better to the shape of the brain tissue. The soft materials enabled the compliant grids to follow the contours of brain folds such as the lateral sulcus, which contains brain regions responsible for speech and hearing, and is not accessible with current devices.

Once implanted, the soft electrode arrays were successfully imaged using a powerful clinical 3T MRI scanner and precisely showed the electrode location in the sulcus as well as the brain tissue around it.

“By using thin silicone membranes, we created devices that the neurosurgeon could handle easily but still enabled a good contact with the brain, a perfect compromise.” says Florian Fallegger, the article’s lead author.

The devices are created using microfabrication processes borrowed from the integrated electronics industry which enables the electrode shape to be tailored to the needs of the user. As part of the study, the ability of different electrode designs to record brain activity was trialled in minipig models in collaboration with scientists at Clinatec (Grenoble).

“This work underlines our efforts to push new and innovative technology to the clinic” says Prof. Stéphanie Lacour, Bertarelli Foundation Chair in Neuroprosthetic Technology at EPFL and Director of the Center for Neuroprosthetics, “by involving engineers, neuroscientists and clinicians in the research process from the very start, we improve our chances of successful translation”.

As a spin-off of the LSBI, the Neurosoft Bioelectronics team is now working to further develop this technology, translate it to the clinic and commercialize the electrodes for human use.

You can read the full publication on the Advanced Science website