Graphene’s Use in Neural Prostheses is Examined

Researchers at the Technische Universität München, Garching, Germany, are testing graphene's efficacy in creating stable human neural prostheses, such as those used in brain-computer interface systems. Graphene, a pure carbon that resembles a chicken-wire lattice when under magnification, is used in electronics, energy storage, composite materials, and biomedicine because of its unique optical, electrical, and mechanical properties. Graphene is only a single atom thick and therefore highly flexible, but is also held together by carbon bonds, which are among the most stable known to chemists. Researchers believe that those characteristics should offer relative stability inside the human body.

To test the biocompatibility of graphene, the researchers created a graphene transistor to conduct the signals that are "gated" by the natural body fluids in which it is enclosed. This gating lets the body fluids act as an integral part of the operation of the prosthesis. These "solution-gated transistors" are much more sensitive to electronic changes in their environment than conventional silicon devices. "[Graphene-based] devices...far outperform current technologies in terms of their gate sensitivity," according to the research article, "Graphene Transistors for Bioelectronics," that was recently published on the Cornell University Library, Ithaca, New York, open-access research database.

Commercially available technologies are mostly based on micro-electrode arrays (MEAs) made from silicon or metals. However their long-term stability need improvement and they have intrinsic poor spatial resolution.

The researchers have tested the graphene with various cell types and reported that graphene is showing successful biocompatibility. The European Commission recently announced an investment of one billion euros (US $1.32 billion) in graphene research over the next ten years.

For more information about the latest graphene innovations in prosthetics, see "Graphene, Acrylic Elastomer Combination Being Researched for Use as Artificial Muscle."

Editor's note: This story was adapted from materials provided by the MIT Technology Review.