Flexible Batteries Inspired by Electric Eels

electric eel swimming through green seaweed

Innovation: Academia

University of Fribourg

2017

Image: Alex Zakletsky / Wikimedia Commons / CC BY - Creative Commons Attribution alone

Modify Electric Charge

Harnessing the power of electricity can be a powerful way for organisms to get energy. An electric charge can be positive or negative. When matter with an electric charge is near other charged particles, it will either be ‘repulsed’ or ‘attracted’ to the matter based on the charge. From electric eels to oriental hornets, learn about the different ways organisms use electric charges to their advantage.

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Send Electrical/Magnetic Signals

Some living systems send electric or magnetic signals, often as a way of communicating with other living systems or sensing their environment. Electric and magnetic signaling requires specialized organs, and thus appear to be less common than other types of signals, such as audible and visual ones. Electric fish produce very sophisticated electric signals that not only help them find mates, but are also sensitive enough to enable them to distinguish individual fish.

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Battery from University of Fribourg is made of hydrogel compartments and membranes that are flexible and store energy.

Benefits

Stable
Flexible
Scalable

Applications

Soft robotics
Electronics

UN Sustainable Development Goals Addressed

Goal 9: Industry Innovation & Infrastructure
Goal 12: Responsible Production & Consumption

The Challenge

Wearable and portable electronics require small, stable batteries to function properly. To achieve longer-lasting charges on devices, batteries must be larger, which also makes them heavier. Developing high performance, high energy density, and flexible batteries would improve small, portable electronics.

Innovation Details

The flexible battery is made of two sheets with specialized arrangements of hydrogels. On one sheet, there are small lumps of hydrogels: some that contain saltwater and others that contain freshwater. On the other sheet, some lumps of hydrogels let positive ions flow through while others allow negative ions flow through. When pressed together the ion gradient—the difference in salt concentrations—between the salt water and fresh water activates, causing energy to flow. The sheets can be arranged in any shape, and the energy can be used just by pressing the sheets together.

Biomimicry Story

Electric eels have an organ that generates electricity to stun prey and keep predators at bay. The eels have modified muscle cells stacked on top of each other that are used to generate a current. In the normal state, eels do not generate a current due to the configuration of the cells, but when triggered, an influx of sodium ions changes the polarity of the cells, inducing a current to shock, and possibly kill, its prey or threatening predators.

See Related Content

Biological Strategy

Organ Generates Electricity

Fish

Electric organs of certain fish generate electricity using additive energy from stacked cells to generate a current.

Biological Strategy

Electric Organs Generate Volts

Sailfin sandfish

Electric organs behind the eyes of electric stargazers help them defend themselves and stun prey by generating electricity.

References

Journal article

An electric-eel-inspired soft power source from stacked hydrogels

Nature

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