September 23, 2023

Researchers at MIT have developed a metal-free electrode utilizing conductive polymers. The electrode is versatile and robust sufficient for long-term implantation within the physique. The machine is meant as a complicated substitute for inflexible steel electrodes that may trigger tissue harm and scarring over the long run, resulting in machine failure. The brand new expertise required fairly a little bit of refinement to realize the proper properties of flexibility, energy, and electrical conductivity. The electrode materials may be printed utilizing a 3D printer, that means that the researchers can simply create an unlimited array of advanced geometries and shapes to fulfill the wants of all kinds of medical applied sciences.

Implantable applied sciences are advancing to behave and really feel extra like human tissues, in comparison with inflexible mechanical units. There are quite a few benefits to this – versatile implants are much less more likely to trigger harm in gentle tissues and are additionally much less more likely to trigger scarring and irritation. The overseas physique response and scar tissue can result in implant failure, and if long-term implantable units are to emerge then growing high-end electrodes that enable them to work together with tissues for a few years will probably be vital.

This newest expertise is a step in the suitable course. It’s a utterly metal-free electrode, made utilizing conductive polymers. “This materials operates the identical as steel electrodes however is produced from gels which might be much like our our bodies, and with related water content material,” mentioned Hyunwoo Yuk, a researcher concerned within the examine. “It’s like a man-made tissue or nerve.”   

The electrode was difficult to create, as polymers are usually insulative quite than conductive. Whereas conductive polymers have been recognized, crafting them into a versatile gel-like electrode was no straightforward feat, and required the researchers to stability conductive properties with mechanical limitations.

“In gel supplies, {the electrical} and mechanical properties at all times battle one another,” mentioned Yuk. “If you happen to enhance a gel’s electrical properties, you must sacrifice mechanical properties, and vice versa. However in actuality, we’d like each: A fabric needs to be conductive, and likewise stretchy and sturdy. That was the true problem and the rationale why folks couldn’t make conductive polymers into dependable units totally made out of gel.”

Their resolution was to mix conductive polymers with different hydrogel elements that may present the required mechanical properties. The important thing to attaining this was to induce part separation, the place the supplies barely repel one another.  

“Think about we’re making electrical and mechanical spaghetti,” mentioned Xuanhe Zhao, one other researcher concerned within the examine. “{The electrical} spaghetti is the conductive polymer, which may now transmit electrical energy throughout the fabric as a result of it’s steady. And the mechanical spaghetti is the hydrogel, which may transmit mechanical forces and be robust and stretchy as a result of it is usually steady.”

Examine in journal Nature Supplies: 3D printable high-performance conducting polymer hydrogel for all-hydrogel bioelectronic interfaces

By way of: MIT