Researchers replace copper MRI cables with plastic to reduce metal interference
Last update on Jan 22, 2026
Magnetic resonance imaging, MRI for short, is a powerful imaging technique in medicine. It can be used to produce high-resolution images of tissues and organs that reveal even the tiniest injuries, sites of inflammation and early-stage tumors. The procedure uses radio waves and extremely strong magnetic fields. Metal is therefore problematic inside an MRI.
MRI can also be combined with other diagnostic and therapeutic procedures, such as electrical examinations of the heart and the brain, or stimulation of deep brain structures using temporal interference stimulation. To do this, the patient must wear additional electrodes on their chest or head while inside the MRI scanner. And this is precisely where the combined methods reach their limits: The electrodes must be connected to a measuring device by cable, and cables are usually made of copper. In the MRI scanner, they can heat up – plus, they interfere with the MRI imaging.
Researchers from Empa's Advanced Fibers laboratory in St. Gallen have developed a surprising solution in collaboration with their industrial partner TI Solutions AG. Their electrode cables are not made of copper, but of plastic – at least for the most part. Instead of metal wires, researchers led by Dirk Hegemann have used bundles of polymer fibers coated with only a thin layer of metal.
Plastic cables with ultra-thin silver and titanium coating
The predefined electrical conductivity is just one of the requirements that the polymer cables had to meet. In order to be usable in medicine and research, they also had to be durable and resistant over an extended period of time, both to corrosion of the coating and to the mechanical stresses that arise, for example, when plugging and unplugging the cables.
The researchers tested around a dozen coatings using different materials and coating techniques. A thin film made of silver and titanium proved to be the winner. “Silver has very good electrical conductivity,” explains Hegemann. “Titanium reduces the conductivity somewhat so that we can achieve our specified range.”
The two metals also stabilize each other against corrosion. The researchers have already tested the first coated plastic cables for a year and demonstrated that the conductivity has hardly changed over this period.
The researchers applied the ultra-thin coating, which is less than half a micrometer thick, to the fiber using magnetron sputtering: an established process that can be used in an industrially scalable roll-to-roll process. The Empa team has already produced around one kilometer of coated fibers for the first cables. The Innosuisse project was successfully completed in 2025. Nevertheless, the partners remain in contact.
“We continue to support our industry partner when it comes to demonstrators and initial sampling,” says Hegemann. “Empa's efficient and uncomplicated support in the pilot series phase is another benefit of our collaboration,” says Niels Kuster, president of TI Solutions AG. If the polymer cables prove themselves in these initial applications, they will go into industrial production.