Reviving the Classic “Drinking Bird”: A New Way to Generate Clean Energy
The iconic top-hatted “drinking bird,” a once popular demonstration tool for showcasing the fundamentals of thermodynamics in science classrooms, is making an unexpected resurgence. Scientists from Hong Kong and China have taken inspiration from this classic toy, also known as the “Dippy Bird,” to develop a new clean-energy generator. This innovative engine utilizes the power of water evaporation to generate electricity, potentially paving the way for powering small devices like watches and phones (Device, 2023).
The newfound method harnesses the energy derived from the bird’s characteristic back-and-forth movement and converts it into electrical power. The toy consists of two glass bulbs, representing the head and body of the bird, connected by a long glass tube (Figure 1). The principle behind this phenomenon involves methylene chloride, a highly volatile liquid contained within the structure.
Once the bird’s beak is dipped into a cup of water, it springs back up to its natural position, triggering water evaporation and cooling the head. As a result, the volatile liquid from the lower bulb ascends the tube due to pressure differences, causing the bird’s center of gravity to shift and its beak to dip back into the water. This cycle continues, providing a source of amusement for generations.
Figure 1: Schematic illustration of the Drinking Bird engine
The natural world exhibits this process through evaporation, which occurs when sunlight warms Earth’s surface, breaking water molecules apart. Approximately half of the solar energy absorbed on Earth is used for evaporation (Device, 2023). This energy transfer represents the most substantial amount in the Earth’s system. If scientists can effectively capture this energy and convert it into electricity, it could represent a significant renewable energy opportunity.
Professor Hao Wu, from South China University of Technology, expressed her excitement over the potential applications of this method, stating, “I still feel surprised and excited when witnessing the actual results” (Device, 2023). During her post-doctoral studies, Wu recognized the potential of the drinking bird model as more than just a tool for teaching physics concepts. She contemplated whether the evaporation energy could be converted into mechanical energy first and then transformed into electricity (Device, 2023). This idea led her to consider using the drinking bird toy as a basis for this innovation.
To test their theory, Wu and her team added two nanogenerator modules on either side of the bird’s “engine,” derived from a commercial toy (Device, 2023). The prototype was then evaluated in various ambient conditions and successfully powered a range of electronics, such as LCDs, temperature sensors, and calculators. Future aspirations include scaling up the generator to power more commonly used everyday devices.
Previous attempts to convert evaporation energy into electricity have faced low conversion efficiencies (Device, 2023). However, the drinking bird generator has generated an output of 100 volts using merely 100 milliliters of water, enough to power small electronic devices (Device, 2023). The team believes their drinking bird generator could yield significantly more power than previous experiments that employed alternative methods.
The researchers’ next goal is to design a more efficient drinking bird engine specifically for energy generation (Device, 2023). If successful, the retro drinking bird may well be here to stay, providing an eco-friendly and intriguing solution for clean energy.
References:
Device (2023). Drinking bird inspired generator produces clean energy. Retrieved from <>
