Scientists at ETH Zurich in Switzerland, Linköping University in Sweden, and Columbia and NYU in New York City, have developed a highly flexible soft electronic neural interface probe that can be stretched to twice its original length. The device is suitable for long-term neural recording, and could help clinicians to diagnose and monitor neurological conditions such as epilepsy. In the future it may be useful for brain-machine interfaces, such as those controlling prosthetic limbs.
At present, long-term neural monitoring is challenging, as rigid electrical components can damage softer neural tissue. “As human tissue is elastic and mobile, damage and inflammation arise at the interface with rigid electronic components,” said Klas Tybrandt, a researcher involved in the study. “It not only causes damage to tissue; it also attenuates neural signals.”
The team developed a flexible probe that is as soft as human tissue and can be stretched to twice its original length. The probe consists of a silicon rubber elastomer containing gold-coated titanium dioxide nanowire electrodes. Each electrode is only 50 μm in size.
This design allows the probe to remain in place over long periods. “We have developed a process to manufacture small electrodes that also preserves the biocompatibility of the materials,” said Tybrandt. “The process uses very little material, and this means that we can work with a relatively expensive material such as gold, without the cost becoming prohibitive.”
The researchers tested their device in rats, and were able to obtain neural recordings over the space of 3 months, and used the data to estimate where in the brain particular neural signals originated. “This type of spatiotemporal information is important for future applications. We hope to be able to see, for example, where the signal that causes an epileptic seizure starts, a prerequisite for treating it,” said Tybrandt. “Another area of application is brain-machine interfaces, by which future technology and prostheses can be controlled with the aid of neural signals.”
Take a look at this video for more info about the new devices:
Study in Advanced Materials: High-Density Stretchable Electrode Grids for Chronic Neural Recording…