One of the directions medical research is taking is the exploration of technological implants in the body. One well known example would be a pacemaker, but there are many more, including some that are still in development. One universal problem for these devices though is how to power them. You cannot just swap out the batteries like a remote or plug them into an outlet for a recharge. Long-lasting batteries have to be used or advanced power systems that draw power from the body itself. Researchers at MIT have recently designed a device capable of the latter; a glucose fuel cell.
Glucose fuel cells have been created before, but never adopted because lithium-ion batteries offered more power per unit area. The new MIT design though may upset that as the fuel cell was made onto a piece of silicon, like a computer chip. Platinum catalysts are also used to pull electrons from the sugar which is currently enough to produce 100 microwatts. That may not seem like much, but it is enough to run ultra-low-power neural implants.
The intention for this fuel cell is to be used for neural implants that will give paralyzed people control over their limbs again. Fortunately the cerebrospinal fluid that surrounds the brain and spinal cord is filled with glucose which is not all used. While the fuel cell will pull a little on the energy source, it should not be enough to cause any issues.