September 26, 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 gadget is meant as a sophisticated substitute for inflexible metallic electrodes that may trigger tissue injury and scarring over the long run, resulting in gadget failure. The brand new expertise required fairly a little bit of refinement to attain the proper properties of flexibility, power, and electrical conductivity. The electrode materials will be printed utilizing a 3D printer, that means that the researchers can simply create an unlimited array of advanced geometries and shapes to satisfy 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 prone to trigger injury in delicate tissues and are additionally much less prone 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 creating high-end electrodes that enable them to work together with tissues for a few years shall be needed.

This newest expertise is a step in the best course. It’s a utterly metal-free electrode, made utilizing conductive polymers. “This materials operates the identical as metallic electrodes however is made out of gels which can be just like our our bodies, and with comparable water content material,” mentioned Hyunwoo Yuk, a researcher concerned within the research. “It’s like a synthetic tissue or nerve.”   

The electrode was difficult to create, as polymers are usually insulative moderately 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 combat one another,” mentioned Yuk. “For those who enhance a gel’s electrical properties, you need to sacrifice mechanical properties, and vice versa. However in actuality, we’d like each: A cloth needs to be conductive, and likewise stretchy and strong. That was the true problem and the explanation why folks couldn’t make conductive polymers into dependable units completely made out of gel.”

Their resolution was to mix conductive polymers with different hydrogel parts that may present the required mechanical properties. The important thing to attaining this was to induce section 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 research. “{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 powerful and stretchy as a result of it is usually steady.”

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

By way of: MIT