Nature has been very effective in inventing different ways to equip living beings with a variety of “structures” that let organisms sense, move, manage chemical reactions and produce electricity. All animals are able to produce electricity by creating an electrical potential and discharging it as needed.
The basic trick is quite similar in all animals. Cells move sodium and potassium (in opposite directions) across a membrane that works like an insulator (separates the sodium from the potassium thus creating an electrical potential) resulting in a voltage between -30 and -90mV. With this kind of voltage, cells can communicate with nearby cells but you cannot leverage on it to power, as an example, a pacemaker.
A few animals have “invented” a way to assemble more cells into structures that work like batteries. The “electric eel” is particularly effective with an organ that can create up to 600V potential (that is over 60,000 more powerful than the one created by our neurones). It does so by clustering electrocytes cells into several thousands electroplates, each electrocyte generating around 100mV (like our neurones). Creating a high potential is not doing any good unless you are also able to funnel the electricity to the places you need it, without getting the shock yourself. In the case of eels this works because they live in water and the electricity is dispersed by the eel’s skin in just 2ms. The small animal that gets in contact with the eel skin gets just a little portion of the discharge but, being small, the effects are enough to shock it.
Researchers are studying ways to create an artificial organ, mimicking the one of eels, that could be implanted in our body to generate electricity and power implants, transforming us into a cyborg. A joint team from University of Friburg, University of Michigan and University of California – San Diego has reported on their progress in a paper published on Nature. They have created a gel that is bio-compatible, soft and transparent, suitable for implants. It can generate 110V and can provide an output of 27mW per square meter, sufficient to power several implants, like electronic contact lenses, sensing devices, actuators in the brain.
This is an important step in the fusion of electronics with our body, a step in the direction of symbiotic autonomous systems since electrical signals remain the most effective way to support communications.