Eel-Inspired 3D-Printed Hydrogel Instantly Generates Electricity

Inspired by the electric eel, researchers from the University of Fribourg in Switzerland have developed 3D-printed hydrogels  that could generate up to 110 Volts of electricity in an instant. The rows of gels contain positively and negatively charged ions that combine together to mimic the eel's cellular structure. Unlike typical batteries, these systems are soft, flexible, transparent, and potentially biocompatible. The researchers hope the system leads to a device that generates power from within the human body.

Transcript

00:00:01 Te electric knife fish or electric eel to its friends, has one of the most shocking talents in the animal kingdom, literally. Used to sense and attack prey the electric eel's ability to generate store and release jolts from within its body has fascinated scientists for centuries, and now they're mimicking it on a quest to create a flexible bio-battery which could power all kinds of futuristic tech, to wear on our bodies and even inside our bodies. To make an electric eel inspired battery the first thing to understand is how the eels do it. Enter specialised cells called electrocytes. These cells have membranes that allow certain charged ions to pass through, leaving the cell in a neutral state when it's resting. When the eel is ready to strike, channels on

00:01:00 one side of the cell open and positive ions rush in generating a current and zap! It's curtains for the unsuspecting prey. Each electrocyte only produces around 150 millivolts, but large eels can have thousands of them packed together like a battery. Using some clever nervous system timing they're able to activate them all simultaneously making for a hefty shock. Scientists based at the University of Freiburg in Switzerland took inspiration from this process to create an artificial electric organ They used blobs of hydrogel to mimic each part of the electrocyte - yellow and green blobs act as the selectively permeable membranes, red and blue blobs contain different levels of the ions. Just like the eel, ions rush across these membranes

00:01:52 to generate a current. Each group of four blobs can produce about the same voltage as an electric eel's electrocyte. Also like the eel scientists wanted to stack their artificial cells up to increase the voltage, but how do you do that? One answer: printing. When laid on top of each other these two sheets, laden with hydrogel blobs, form one long line of repeating units - enough to generate about a hundred volts. Now there's one more thing; the eel fires all of its electrocytes simultaneously to get maximum voltage and the scientists need to do the same. To get that high voltage all of the gels need to contact at the same time. The sheets made it faster but for truly simultaneous connections the researchers

00:02:42 came up with another idea: folding. This allowed all the biogel blobs to touch each other almost simultaneously. The eel can recharge its battery biologically within its body, whereas right now the artificial battery needs to be connected up to a power source. Researchers want to use their battery to power things like contact lenses with integrated displays, or biological sensors or even wearable tech, so the hope is that their battery too will one day be recharged biologically. After all if the eel can do it, why can't we? Right