Researchers from the University of Fribourg (Switzerland), University of Michigan, and UC San Diego have 3D bioprinted an electric eel-inspired device that produces 110 volts from hydrogels. They presented their findings last week in San Francisco, California.


The only species in its genus, the electric eel is one of the most fascinating creatures of the sea. It has three pairs of abdominal organs that produce electricity, which can be used to defend itself or stun prey. Inspired by the unique knifefish, a group of researchers has now used 3D bioprinting to create a soft power source that mimics the capabilities of the electric eel.


The science behind electric eels is fascinating. Inside the sea creatures, ions, charged atoms or molecules, accumulate on either side of a cell membrane to form an ion gradient, and electric potential, or voltage, can be harvested from the potential across the ion gradients. In a process called “transmembrane transport,” electric eels use this process to generate their own electric power.


The researchers, looking to do the same in an artificial structure, stacked hydrogels full of varying strengths of salt water using a bioprinter. The more hydrogels they stacked with the 3D bioprinter, the greater voltage they could produce, and they eventually created a system that could produce 110 volts.


The complex bioprinting technique involved depositing arrays of gel precursor droplets onto plastic substrates, which were then cured with a UV light to convert them into solid gels. By alternating high-salinity and low-salinity gels on one substrate, and cation-selective and anion-selective gels on another, the researchers made a conductive pathway of 612 tetrameric gel cells that can be used to generate the impressive voltage.