MIT researchers have developed a new fuel cell that could be used to power brain implants in coming years . Just like human cells, the fuel cells run on glucose, which is the most common sugar in nature and in the human body. Human cells derive energy from glucose through a process called oxidation — a part of metabolism — that takes electrons from the glucose and passes those electrons from enzyme to enzyme in the cell, generating the energy molecule adenosine triphosphate (ATP).
The logic behind using glucose as a fuel is that it’s quite plentiful in the body. For instance, as the fuel cell is planned to power a brain implant, cerebrospinal fluid (CSF) — a sugary fluid that bathes the central nervous system — would be a rich source of fuel. From the MIT news release:
The idea of a glucose fuel cell is not new: In the 1970s, scientists showed they could power a pacemaker with a glucose fuel cell, but the idea was abandoned in favor of lithium-ion batteries, which could provide significantly more power per unit area than glucose fuel cells.
The new twist to [this cell] is that it is fabricated from silicon, using the same technology used to make semiconductor electronic chips. The fuel cell has no biological components: It consists of a platinum catalyst that strips electrons from glucose, mimicking the activity of cellular enzymes that break down glucose to generate ATP, [and generating] up to hundreds of microwatts — enough to power an ultra-low-power and clinically useful neural implant.
The team hopes that glucose fuel cell-powered brain implants could eventually help paralyzed patients to regain mobility in their limbs.
A team of scientists from Brown University, Massachusetts General Hospital and other institutions recently demonstrated that paralyzed patients could use a brain-machine interface to control robotic arms; however, those implants have to be plugged into a wall outlet. The current research is a step toward developing implantable medical devices that don’t require an external power source.
- Rapoport et al. A Glucose Fuel Cell for Implantable Brain–Machine Interfaces. PLoS ONE 7(6): e38436. doi:10.1371/journal.pone.0038436.