With a growing number of Americans suffering from strokes and other neurological disease, researchers at Purdue University are developing what they believe are better medical devices to help modulate a patient’s nervous system and assist with recovery.
Many doctors use implantable neurostimulation devices that deliver a low-voltage electrical stimulation. But a commonly used part—platinum microelectrodes—are prone to corrosion and can shorten the life of the implantable devices.
Now, a Purdue research team says it has found a way to protect the microelectrodes. Their solution is to add a layer of graphene—a flat sheet of carbon atoms arranged in a repeating hexagonal lattice.
Graphene can conduct electricity and is one of the strongest materials known to exist, or 200 times stronger than steel, while being lighter than paper.
“I know from my industry experience that the reliability of implantable devices is a critical issue for translating technology into clinics,” said Hyowon Lee, an assistant professor in Purdue’s College of Engineering and a researcher at the Birck Nanotechnology Center, who led the research team.
The team has shown the graphene layer to be an effective way to protect the metals from corrupting each other while also conducting electricity. Their research is published in the June 6 edition of 2D Materials.
When coated with a layer of graphene, the platinum dissolution on the electrodes was reduced by 97 percent “while they retained the superior charge transfer characteristics,” according to the journal article.
Lee said he thinks that tiny electrodes are going to play a key role in the future with more demand for precise and targeted neurostimulation therapy.
“We think neurosurgeons, neurologists and other scientists in the neuro-engineering field will be able to use this electrode technology to better help patients with implantable devices for restoring eyesight, movement and other lost functionalities,” he said.
Stroke is the fifth-leading cause of death in the U.S., and Alzheimer’s disease is sixth.
According to the International Neuromodulation Society, stroke affects about 750,000 people a year, and about half of them will suffer long-term motor impairments severe enough to require the help of others for daily activities. An implantable device is often used to stimulate either the surface of the brain, just beneath the skull, or inside the brain, to influence the patient’s neural circuits.
Lee and his team are working with the Purdue Research Foundation on patenting and licensing the technology, and are looking for partners interested in licensing it.