A power generator inspired by the drinking bird toy supplies electronic devices with evaporated water
Inspired by the classic drinking bird toy, scientists in Hong Kong and Guangzhou, China, have developed a motor that effectively converts the energy of water evaporation into electricity to power small electronic devices. According to a study published March 14 in the journal Device, the device produces energy at a voltage of more than 100 volts – much higher than other techniques that generate electricity from water – and can run for several days using just 100 milliliters of water as fuel become.
“The triboelectric hydrovoltaic generator for drinking birds provides a unique opportunity to power small electronic devices under ambient conditions while using water as a readily available fuel source,” said Hao Wu, a professor at South China University of Technology and lead author of the study. “I’m still surprised and excited to see the actual results.”
This is how the drinking bird toy works
The drinking bird toy, also known as the “Dippy Bird,” has been a staple in science education for decades. The toy consists of two glass bulbs connected by a glass tube containing a highly volatile liquid, methylene chloride. The upper tank, which contains the bird’s beak and a decorative cylinder, is covered in a felt-like material and the bird’s body hangs from two plastic legs. If you immerse the bird’s head in a glass of water, the water will begin to evaporate. This creates a pressure difference that causes the liquid in the bottom piston to rise through the tube until it fills the head, causing the bird to submerge into the water to “drink” before the process begins again.
When Wu was working in Professor Zuankai Wang’s group at Hong Kong Polytechnic University and was wondering how to increase the output voltage of an evaporative power generator, he remembered the toy drinking bird and came up with the idea that it could be useful for more than just could be demonstrating a physical concept.
“I started wondering if we could first convert the vaporization energy into mechanical energy and then convert it into electricity,” Wu explains. “The idea came to me to use the drinking bird toy.” “With this inspiration, the concept of the triboelectric hydrovoltaic generator “Trinking Bird” was born.”
To build the generator, Wu and his colleagues placed two triboelectric nanogenerator modules — which harvest mechanical energy — on either side of a drinking bird motor that they recreated from a commercial drinking bird toy. The researchers tested the prototype with various small electronic devices, powering 20 liquid crystal displays (LCDs), temperature sensors and calculators.
Overcoming the friction that slowed the generator was one of the study’s biggest challenges, Wu explains. The researchers placed patterned fibers as charge transfer materials in the triboelectric nanogenerator modules, a strategy that helped reduce friction and allow the device to operate more smoothly.
In the next phase of their research, the team plans to design a new water fountain instead of a commercial toy, with the goal of converting water evaporation into electrical energy more efficiently.
“In addition, we will explore various applications of this device, with the ultimate goal of developing a practical product that can be used in our daily lives,” said Zuankai Wang, corresponding author of this study and chair at Hong Kong Polytechnic University.
REFERENCE
Triboelectric hydrovoltaic generator with drinking bird function