- Researchers are integrating printed flexible electronics, like this one, into patches that can automate treatments for brain disorders like tinnitus.
More than 16 million people in the U.S. have severe enough tinnitus to seek medical attention, according to the American Tinnitus Association. Patients with the disorder perceive a continuous ringing or hissing sound in their ears, originating from a network of brain cells that process what the ears hear.
A team of researchers at the University of Minnesota has its sights set on treating the symptoms of tinnitus, the first in a line of neurological disorders — without the need for surgery. These experts, ranging from computer engineers to apparel designers, are working together to develop a groundbreaking new technology—thin, wearable electronics that attach to the skin and deliver low electric currents to specific regions of the brain and decrease symptoms of brain disorders. The project is part of MnDRIVE (Minnesota’s Discovery, Research and InnoVation Economy), a $36 million biennial investment by the state of Minnesota that aims to solve grand challenges. As a part of MnDRIVE’s Transdisciplinary Research Program, the project will bridge multiple research areas, bringing together experts from across the U.
While disorders such as tinnitus are centered in the brain, the new treatment researchers are investigating allows for stimulation against the skin on other parts of the body, such as the legs, wrists or arms, providing an alternative to surgical procedures currently being used to treat the disorder, like deep brain stimulation, where doctors must plant an electrical node inside the brain.
“Through this unique interdisciplinary collaboration, we are exploring ways to target areas of the brain for treatment that is noninvasive,” said Chris Kim, Ph.D., the project’s lead principle investigator and associate professor of electrical and computer engineering at the U’s College of Science and Engineering. “We are really just beginning to understand the possibilities this form of treatment holds for patients suffering from debilitating brain disorders.”
The team chose tinnitus treatment as its main goal for this project because it was one of the more challenging applications for the technology. In order to treat it, researchers will need to create complex circuits that carefully synchronize multiple nodes that all fire at different times. With the help of chemical engineering and material science professors Lorraine Francis, Ph.D., and Daniel Frisbie, Ph.D., Kim is working to develop the circuits and manage their power consumption. Meanwhile, Hubert Lim, Ph.D., assistant professor in biomedical engineering, is developing a patch that can automate the current based on each specific patient’s needs and allow treatment to continue beyond the doctor’s office.
A better way to print
For the device to work as a wearable patch, researchers not only need to design thin, flexible electronics, but also an efficient method of making them. The team aims to refine a method called “roll-to-roll” printing that can produce flexible electronics more quickly and efficiently than the standard, time-consuming method of laying electrical components down in multiple layers.
“You want a more efficient, effective way that will give us a lot higher throughput,” Kim said.
With roll-to-roll printing, rollers print conductive ink directly onto a flexible material, creating a functional electronic device from liquid materials. Despite its potential, the method is still in its infancy, limited to building the most basic components. The team will figure out how to develop the technique to more reliably and precisely print the stimulator circuits needed for treating brain disorders.
Treatment meets comfort
While Kim and Lim work to develop a stimulator device and a means for manufacturing it, Lucy Dunne, Ph.D., an associate professor with the U’s Wearable Technology Lab, is designing apparel that can integrate the technology into clothing. When connected to nodes from an electronic device, a shirt outfitted with flexible wiring, for example, could aid honing in on the right areas for treatment, or even serve as a more comfortable long-term solution for patients.
“There are a lot of unanswered questions about how specific the location of stimulation needs to be,” Dunne said. “A garment with an integrated electrode array allows us to quickly and efficiently change the location of stimulation to adapt to differences in body size and shape.”
The garment needs to be close-fitting, as sensing nodes would rely on contact with skin to function, and must be able to withstand washing, stretching and other forms of wear and tear that traditional electronics need not deal with. She anticipates other challenges will crop up along the way, as the varied disciplines involved continue to come together.
“Seeing the same problem from a completely different perspective can be really exciting,” Dunne said. “It can give you new insights into your own area as well as possibilities that bridge to other areas.”