New Energy Source for Future Medical Implants

An implantable energy cell powered by glucose could soon be driving neural prosthetics that help patients regain control of limbs.

Researchers at the Massachusetts Institute of Technology (MIT; Cambridge, USA) developed a glucose-based fuel cell that is fabricated on a silicon wafer, much in the same way that semiconductor chips are made, but uses a biocompatible platinum catalyst to strip electrons from glucose molecules, thus mimicking the activity of cellular enzymes that break down glucose to generate adenosine triphosphate (ATP). The silicone fuel cell can generate an electric current of up to 100 µW, which is enough power to drive a neural implant.


According to researchers, the glucose-based fuel cell will most likely first be implemented in the brain, since cerebrospinal fluid (CSF), which envelopes and protects the brain and spinal column, contains enough glucose to power the fuel cell; since only a small fraction of the available power is utilized by the glucose fuel cell, the impact on the brain’s function would likely be small. Also, the CSF is a good location because it contains very few cells, which greatly reduces the chance of an immune response. The study was published in the June 12, 2012, edition of PLoS ONE.

“The glucose fuel cell, when combined with such ultralow-power electronics, can enable brain implants or other implants to be completely self-powered and not require battery replacements, a common problem with electronic implants today,” said senior author Rahul Sarpeshkar, PhD, an associate professor of electrical engineering and computer science at MIT.

The idea of a glucose fuel cell has been around since the 1970s, when scientists showed they could power a pacemaker with one, but the idea was abandoned in favor of lithium-ion batteries, which could provide significantly more power per unit area than glucose fuel cells. These glucose fuel cells also utilized enzymes that proved to be impractical for long-term implantation in the body, since they eventually ceased to function efficiently.

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Massachusetts Institute of Technology