Tiny devices use bee wing buzz to generate electricity

A tiny buzzing battery power future technology

Scientists have developed an extraordinary device that harvests energy from the natural vibrations of flying bees, potentially eliminating batteries in microbial systems while allowing insects to maintain normal flight patterns.

The ultra-light piezoelectric energy harvester (PEH) weighs only 46 mg (approximately small raindrops) and can generate electricity through the bees’ natural wing movement in flight, producing enough power to power low-energy electronics.

Researchers at Beijing Institute of Technology and Sunsen University published their findings on February 26 in the journal Robots and Bionic Systems, detailing how they successfully matched devices to specific vibration patterns in Honeybees.

The innovation could transform environmental monitoring and rescue operations by enabling self-sustaining “insect network robots” (insects carrying microelectronic packages that can navigate areas that traditional drones cannot access.

“By integrating the frequency interval with the center of gravity optimization, we keep the resonant frequency of the harvester consistent with the chest vibration of the bee, allowing for efficient energy conversion without compromising flight stability.”

Previous attempts to create such systems depend on batteries that could account for 80% of the weight of the device, severely limiting flight time and potentially harming insects. The new approach eliminates this constraint.

The research team conducted a detailed high-speed camera analysis of bee flight under various load conditions and found that bees can maintain stable flights and weigh up to 40 mg before the flight balance begins to deteriorate significantly. They also found that loaded bees vibrate their chests in a specific frequency range of 210-220 Hz.

Using these data, they created a bicrystal structure using polyethylene fluoride (PVDF) film for flexibility and minimal weight. Crucial to its design is to carefully position the center of gravity of the device to match the natural balance point of the bees, thereby minimizing flight disruptions.

“This approach eliminates the need for bulky batteries, extends operational life and enhances the practicality of insect robots in the real world,” notes Jianing Wu, co-author of Sun Yat-Sen University.

In laboratory tests, the device had a maximum output of 5.66 volts and an energy density of 1.27 mm per cubic centimeter – significantly better than the insect-based energy harvester previously developed for beetles and moths.

Most impressively, bees equipped with equipment exhibit normal flight behavior. “Even with PEH connected, the bees exhibit normal flight behavior, recover from the flip in 2 seconds and wander freely, with minimal biomechanical interference to it,” Zhao said.

The team verified this minimal effect through experiments, in which bees carrying the device can be correctly corrected after flipping and flying towards the light source—behaving consistent with unmodified bees.

Lead researcher Wenzhong Wang noted: “High-speed CMOS cameras provide important insights into wing strike dynamics, allowing us to optimize the resonance frequency of the harvester under different load conditions.”

Although such models are not intended to control insect flights, they represent a significant advancement in sustainable tiny electronic devices that can be carried by a variety of flying insects.

According to the research paper, challenges remain in efficiently storing harvested energy and expanding technology for different insect species. “Future work will focus on integrating energy management circuits and extending this approach to other flying insects, such as dragonflies and butterflies, to establish standard energy solutions for biological hybrid systems,” the team concluded.

Potential applications are more than just technical novelty. Automated insects’ robots can ultimately help with environmental monitoring, disaster responses in crashed structures or exploring hazardous areas – all without the limitations imposed by battery life.

This physically driven design approach also provides a more humane and more effective alternative to creating test and error methods for insect computing hybrids, potentially reducing the number of test subjects required to develop functional systems.

The study was supported by a variety of scientific foundations in China, including the China National Key Research and Development Program and the Beijing Natural Science Foundation.

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