Engineers nanoprint electrodes to help treat neurological disorders

The CMU Array could be used in brain-computer interface platforms, to transform how doctors are able to treat neurological disorders.

3D-printed at the nanoscale, the ultra-high-density microelectrode array (MEA) is fully customisable. This means that one day, patients suffering from epilepsy or limb function loss due to stroke could receive personalised medical treatment optimised for their individual needs.

To develop it, the Carnegie Mellon University team applied a novel microfabrication technique, Aerosol Jet 3D printing, to produce arrays that solved the major design barriers of other brain-computer interface (BCI) arrays. 

“Aerosol Jet 3D printing offered three major advantages,” Rahul Panat, associate professor of mechanical engineering, explained. “Users are able to customise their MEAs to fit particular needs; the MEAs can work in three dimensions in the brain, and the density of the MEA is increased and therefore more robust.”

MEA-based BCIs connect neurons in the brain with external electronics to monitor or stimulate brain activity. They are often used in applications like neuroprosthetic devices, artificial limbs, and visual implants to transport information from the brain to extremities that have lost functionality.

BCIs also have potential applications in treating neurological diseases such as epilepsy, depression, and obsessive-compulsive disorder.

However, the existing BCI devices - the Utah array and the Michigan array - have limitations, and are only able to record on a two-dimensional plane. That means that they cannot be customised to fit the needs of each patient or application.

Over the last few years, modern MEA manufacturing techniques have made tremendous advances regarding the density of microelectrode arrays. By adding the third dimension, they have been able to increase the sampling ability of the arrays and make custom devices, which give more accurate readings.

The researchers’ CMU Array is the densest BCI, about one order of magnitude denser than Utah Array BCIs, the team has said. 

“Within a matter of days, we can now produce a precision medicine device tailored to a patient or experimenter’s needs,” said Eric Yttri, co-senior author of the study.

Although it could take as long as five years to see human testing, and even longer to see commercial use, the team has said it is excited to get this successful process out to other researchers in the field to begin testing a wide variety of applications.

The next step, Panat said, is to work with the National Institutes of Health (NIH) and other business partners to get these findings into other labs as quickly as possible and apply for funding that would commercialise this technology.

The findings of the research were published in the journal Science Advances.