Blood “Batteries” Could Boost Bionics

We don’t exactly think of snails as dynamic, but it turns out they can generate electricity. Researchers are now looking for ways to turn tiny creatures into tools, and even harness power in a similar way from the human body and avoid the need for batteries in implanted medical devices.

A team at Clarkson University in New York State have found a way to produce a fuel cell that takes advantage of the energy carried in blood (or its equivalents) via substances such as glucose.

As Lucas Laursen wrote on the Institute of Electrical and Electronics Engineers site, their study involved implanting a full cell into a snail’s hemolymph, which is effectively the arthropod equivalent of blood. The cell was coated with two enzymes:  pyrroloquinoline quinone-dependent glucose dehydrogenase, which extracts electrons from glucose molecules, and laccase, which transmits electrons to oxygen molecules.

The combined effects produced a current that peaked at seven microwatts (seven millionths of a watt.) Over the course of an hour, the current could be sustained at 0.16 microwatts.

To give some idea of the potential of the concept, a human pacemaker (which currently requires a battery to be attached) needs around 1 microwatt to work. That might not be out of the question as human blood outperforms hemolymph at glucose distribution. The problem is that the system wouldn’t work in its current form because it requires direct access to oxygen, rather than it being held in hemoglobin as happens in humans.

The materials used could also be vulnerable to attack by the immune system, meaning the system would be more suited to devices intended only for short term use such as blood glucose sensors.

In the meantime, a more realistic prospect looks to be implanting blood-powered sensors in small creatures (possibly ones that move faster than snails) and using them to search for people trapped in a disaster scene, or even as spies.

(Picture credit: Clarkson University)