The idea of using insects and other small creatures as data-gathering devices has always been hampered by the need for short-lived external batteries. But what if you used the animal's own metabolism to continuously power their sensors?
A research team from Clarkson University in Potsdam, New York, and lead by Evgeny Katz have devised just such a way. They've built an implanted minuscule fuel cells into the shell cavities of a dozen brown garden snails. These fuel cells extract energy from the glucose and oxygen in the snail's blood and convert that into electrical energy whenever the snail is connected to an external grid.
According to the team's report, published in the Journal of the American Chemical Society,
Here we report on the first implanted biofuel cell continuously operating in a snail and producing electrical power over a long period of time using physiologically produced glucose as a fuel. The "electrified" snail, being a biotechnological living "device", was able to regenerate glucose consumed by biocatalytic electrodes, upon appropriate feeding and relaxing, and then produce a new "portion" of electrical energy. The snail with the implanted biofuel cell will be able to operate in a natural environment, producing sustainable electrical micropower for activating various bioelectronic devices.
The fuel cells are limited in their ability to extract energy by the size of the electrodes and the efficiency of the energy extraction. The snails can produce up to 7.45 microwatts for a duration of 45 minutes for short term use. They can also continuously draw power but at only a rate of 0.16 microwatts.
This research follows in the foot steps of previous studies that implanted fuel cells in cockroaches and beetles. The entire field has caught the eye of the military, given the technology's promise in creating swarms of innocuous intel-gathering insects. [JACS via Nature]