Researchers at Rice University have developed a magnetoelectric material that converts a magnetic field into an electric field. The material can be formulated in such a way that it can be injected into the body, near a neuron. An alternating magnetic field can then be applied to the area from outside the body, taking advantage of the magnetic field’s ability to easily penetrate tissue without causing damage. This magnetoelectric effect produces a small electrical current near the neuron, effectively stimulating it without the need for invasive implants. The researchers have demonstrated that the technology can bridge a completely severed sciatic nerve in rats, showing potential for use in neuroprosthetics.
Neural stimulation can have various therapeutic effects, but implanting neural stimulators is invasive and may require removal due to device failure or battery replacement. A substance that can be injected through a hypodermic needle and provide neurostimulatory effects under the influence of a minimally invasive external device has clear advantages over conventional implants.
“We asked, ‘Can we create a material that can be like dust or is so small that by placing just a sprinkle of it inside the body you’d be able to stimulate the brain or nervous system?’” said Joshua Chen, a researcher involved in the study. “With that question in mind, we thought that magnetoelectric materials were ideal candidates for use in neurostimulation. They respond to magnetic fields, which easily penetrate into the body, and convert them into electric fields — a language our nervous system already uses to relay information.”
The material has a piezoelectric layer of lead zirconium titanate between two magnetorestrictive layers of metallic glass alloys, onto which platinum, hafnium oxide, and zinc oxide were layered. The magnetorestrictive components vibrate when an alternating magnetic field is applied, which changes their shape and produces electricity in the piezoelectric material. The researchers have demonstrated that the technology can restore function to a completely severed sciatic nerve in rats, showcasing its potential for neurotechnology and other applications like sensing and memory in electronics. The study was published in the journal Nature Materials.
Source: Rice University
