Chinese scientist creates clean energy from a classic toy

Chinese scientists have developed a device that could pave the way for a new source of clean energy based on the operating principles of a classic toy.

A team of Chinese scientists created a device that could pave the way for a new source of clean energy - an engine that can power small electronics through water evaporation.

The device can run on 100ml of water as fuel for 50 hours and produce an energy output of up to 100 volts, significantly more than previous research aimed at converting evaporation energy into electricity.

A group of Chinese scientists created a motor that can power small electronic devices through water evaporation, paving the way for a new clean energy source. (Photo: SCMP)

In a paper published in the peer-reviewed journal Device, the team said: ' Evaporation energy could be half the solar energy at Earth's surface, providing significant renewable energy opportunities.

Using a prototype of a generator, we power small electronic devices such as liquid crystal displays (LCDs), temperature sensors, and computers in ambient conditions using water as fuel '.

The research team included scientists from South China University of Technology in Guangzhou, Hong Kong Polytechnic University and City University of Hong Kong.

Their idea was inspired by "The Self-Drinking Bird" - a classic science toy wearing a hat that continuously dips into a glass of water thanks to the principle of thermodynamics. This device was invented by American chemist Miles Sullivan in the 1940s.

The classic science toy "The bird drinks its own water" is based on simple thermodynamic principles. (Photo: SCMP)

Albert Einstein is said to have spent 3 and a half months researching but to no avail. Now, the very mechanism behind this classic toy is being leveraged to create a new source of renewable energy.

The drinking bird consists of 2 glass balls connected by a long glass tube, in which the lower ball contains a liquid with a boiling temperature of 40 degrees Celsius. The upper glass ball has a "beak" covered with a material. like felt.

To initiate the drinking motion, the bird's beak is dipped into a glass of water. Water that comes into contact with the felt begins to evaporate, making the top cooler than the bottom. As the bird's head cools, water vapor from the liquid inside the tube condenses, resulting in a decrease in pressure inside the head relative to the bottom.

The pressure difference causes the liquid at the bottom to rise toward the top. When the head becomes heavier, it will dip its head back into the cup of water. After tilting forward, the liquid flows back and the bird returns to an upright position. As steam continues to evaporate from the head, the bird will sway and drink water continuously.

Inspired by decades-long curiosity, the team decided to take this invention to the next level by harvesting mechanical energy on both sides of the bird. To accomplish this, they installed two triboelectric nanogenerator modules at each end.

'We use a natural heat engine that operates using the evaporation principle inspired by drinking bird toys to convert latent heat of evaporation into slow frequency motion, then convert mechanical energy into electricity through a specialized triboelectric nanogenerator', the research team said.

Leading the research team, Professor Wang Zuankai of Hong Kong Polytechnic University, said their research is just a step to prove a theory, the team hopes to develop devices that can convert vapor energy water into electrical energy more efficiently.

"We can stack dozens of 3D printed mini drinking bird models into a nest to generate electricity simultaneously," Mr. Wang said.

Another way, for the bird to "drink water" must shine sunlight into the glass bulb behind, this glass bulb can be covered with photothermal material. Professor Wang said, heat from sunlight will cause the liquid inside to evaporate and create mechanical activity again.

"In this way, we can convert light energy into electricity," he said. "Since the liquid is inside the tube, it won't be lost during evaporation."

The team could also apply a previously developed structure to the bird's tube to speed up the fluid displacement process to generate more electricity, Wang added.