Nonprofit journalism dedicated to creating a Human Age we actually want to live in.

To generate clean energy from evaporating water, researchers played with a classic toy

DAILY SCIENCE

To generate clean energy from evaporating water, researchers played with a classic toy

Their device produces enough electricity to power small electronics and can operate for several days using only 100 milliliters of water as fuel.
March 28, 2024

Let the best of Anthropocene come to you.

No childhood is complete without a science lesson involving the “drinking bird” toy with its mesmerizing, seemingly magically powered motion that mimics a bird drinking water. Now, researchers have put this unassuming little science toy to important work: generating useful amounts of electricity from water.

The device generates over 100 Volts by tapping into the energy generated by evaporating water. It can operate for several days using only 100 milliliters of water as fuel, the researchers report in a study published in the journal Device.

The drinking bird toy consists of two glass bulbs, forming the head and tail, connected by a glass tube. The bird’s head is covered in a felt-like material. Inside the glass is a volatile liquid, and the glass tube body is connected to plastic legs so that the bird swings up and down like a see-saw.

When the bird’s head is dipped in a glass of water, the water evaporates and creates a pressure difference that causes the fluid in the tail to rise through the tube into the head, causing the bird to dip forward into the water, creating a perpetual cycle.

Natural evaporation of water produces energy. Researchers have been exploring ways to harness this promising source of clean energy. Mechanical engineer Zuankai Wang of Hong Kong Polytechnic University and his colleagues came up with an innovative way to do this with the drinking bird toy.

The researchers added two disc-shaped triboelectric nanogenerators (TENGs) on either side of a drinking bird toy. TENGs are devices that produce electricity from motion via the triboelectric effect, the buildup of charge when two different materials rub against each other.  So the drinking bird toy converts the energy from water evaporation into motion, which the nanogenerators then convert to electricity.

Tests showed that the device could operate for 50 hours using just 100 ml of water. Its output of 100 volts could power devices such as calculators, temperature sensors, and 20 small LCD displays.

The team now plans to create a more efficient device by designing their own drinking bird from the bottom up instead of using a commercially available toy.

Source: Hao Wu et al. Drinking-bird-enabled triboelectric hydrovoltaic generator. Device, 2024.

Our work is available free of charge and advertising. We rely on readers like you to keep going. Donate Today

What to Read Next

Anthropocene Magazine Logo

Get the latest sustainability science delivered to your inbox every week

Newsletters

You have successfully signed up

Share This

Share This Article