Two Swiss researchers at the Ecole Polytechnique Federale in Lausanne, Switzerland, had already earned the world’s plaudits when they created an implanted device that allowed paralyzed mice to move their legs. When Gregoire Courtine and Stéphanie Lacour later discovered that their ground-breaking new device eventually caused compression and tissue damage in their subjects because it was too stiff, they decided to invent a flexible implant.
According to Joseph Keenan, FierceMedical Devices, writing on a study from MIT Technology Review, they succeeded. To prevent the damage caused by the rigid implant they invented a flexible product they call an “e-dura” which has a property of human tissue called viscoelasticity. Made of soft silicone, gold wires and rubbery electrodes flecked with platinum, the device is both stretchable and flexible and can be wrapped around the spinal cords of mice. The device also contains a channel that allows the scientists to introduce drugs and medications to the injury site.
When the researchers sent electrical signals through the e-dura, which they had wrapped around the animal’s spinal cord, the mice’s hind legs moved. After a two month period, the mice showed little sign of any tissue damage—which had not been the case earlier when they had experimented with conventional electrodes.
Keenan quoted Lacour, who is an electrical engineer, as telling MIT, “If you want a therapy for patients, you want to ensure it can last in the body. If we can match the properties of the neural tissue we should have a better interface.”
The aim of their research, of course, is to create an implant that could restore a paralyzed person’s ability to walk. That goal is probably a long way off but Lacour believes that, when it does come, it will involve soft electronics.
