Ultra-thin hydrogel battery mimics electric eels to boost power

Scientists at Penn State have developed an ultra-thin, flexible hydrogel battery inspired by the electric eel’s natural ability to generate high-voltage bursts. By layering multiple water-rich, conductive hydrogels in a precise pattern that mimics the eel’s ionic processes, the team achieved power densities around 44 kW/m³—higher than previously reported for hydrogel-based batteries. Each hydrogel layer is only 20 micrometers thick, reducing internal resistance and eliminating the need for rigid mechanical supports, which were required in earlier eel-inspired devices. This innovation allows the battery to be flexible, non-toxic, and environmentally stable, capable of operating in extreme temperatures from -112 to 80 degrees Fahrenheit without freezing. The researchers used spin coating to deposit four different hydrogel mixtures onto a rotating surface, optimizing the viscosity and mechanical strength to maintain layer stability during fabrication. The resulting battery can efficiently power implanted sensors, wearable electronics, and soft robotics controllers, making it suitable for biomedical and near-biological applications