A toy to visualize the body’s electricity

A children’s electrode set grabs second prize in a contest to build the next big science toy

Robijanto Soetedjo prepares to use his Bioelectricity Toy Kit to show a little girl the electricity in her muscles at a local science fair in Washington state.

Lili Arisanto

Robijanto Soetedjo can’t stop playing with electricity. At work, this neuroscientist at the University of Washington in Seattle studies the electrical properties of cells in our brains. At home, he has used his knowledge of electrophysiology to develop a new toy. This “Bioelectricity Toy Set,” allows kids to discover the electricity in their own bodies.

Soetedjo nabbed second place and $25,000 in the first annual Science, Play and Research Kit — or SPARK — contest. Sponsored by the Gordon and Betty Moore Foundation and Society for Science & the Public (this blog’s parent organization), the contest searched for next-generation “chemistry sets.” The goal: new types of toy to let kids develop their own experiments. But the contest’s organizers understand scientific inspiration comes from more than chemistry.

“I wanted to get the children to know how cool neuroscience is,” Soetedjo says. He observed most neuroscience demonstrations have kids looking at brains, not doing things with the nervous system. The best way to help kids discover neuroscience, he reasoned, would be electromyography. Also known as EMG, it uses electrodes on the skin to record the electrical activity of the muscles underneath.

Attach an electrode to your arm. As you make a fist, wires connected to the electrode communicate the electrical signal from your muscles to a small circuit board. The board then “translates” the electric current from your arm, and uses the power to turn a wheel or turn on a small light bulb. The circuit board also can be hooked up to a computer to communicate with other toys, like Lego robots.

Soetedjo hopes his invention will help kids eight and up discover the electricity in their bodies. Younger kids can watch what happens as their muscles move. Older students can use the toy to design their own experiments around muscle movement, heartbeats or even the nerve impulses from their brains.

Right now, Soetedjo is reaching out to toy companies who might be interested in producing this science toy set on a larger scale. He estimates that producing the toy on a large scale might only cost 20 to 25 dollars. A pretty low price for something that might get a kid interested in how their bodies work.

A video demonstration of the Bioelectricity Toy Set shows that something as simple as making a fist requires electricity. Credit: Robikanto Soetedjo


Power Words

electric current  The flow of electricity along a given path.

electrode (in brain science)  Sensors that can pick up electrical activity. (in chemistry) Materials that serve as an anode or cathode, attracting negatively or positively charged particles.

electronics    Devices that are powered by electricity but whose properties are controlled by the semiconductors or other circuitry that channel or gate the movement of electric charges.

electromyography    A technique to observe electrical currents produced by muscle cells. An electrode is attached to the skin, or a thin wire is inserted into the muscle. Electrical signals from the cells travel through the electrode or wire to a circuit board that interprets the signals. Data illustrating the signal (usually on a computer screen) allows scientists to observe electrical changes as the muscle moves. 

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Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.