New design could revolutionize environmental monitoring, rescue operations, and more.
Permanent magnets made from rare earth elements are well known for their applications in electric motors, wind turbines, and consumer electronics. However, robotics is emerging as another crucial field of application. A groundbreaking invention in this area has recently been introduced by a research team from the Technical University (TU) Darmstadt and the Helmholtz Centre Dresden-Rossendorf in Germany: flexible robotic wings that are not powered by electronics or batteries but instead react to aerodynamic forces like butterfly wings, adjusting their movements accordingly. This is made possible by magnetic fields.
Inspired by the monarch butterfly, renowned for its exceptional endurance and adaptability, which migrates thousands of kilometers annually, the TU Darmstadt researchers explain that the key to its remarkable flight lies in the insect’s wings. The combination of active movement and passive bending enables highly efficient airborne locomotion.
With this natural model in mind, the scientists developed wings from flexible plastic embedded with magnetic particles of neodymium-iron-boron (NdFeB), the material used for the most potent known rare earth permanent magnets. External magnetic fields generated by NdFeB magnets cause the particles to move, causing the wings to bend and mimic the butterfly’s flight movements. In the future, miniaturized magnetic field generators could even be integrated into the flying devices themselves, enabling autonomous movement.
The Greatest Challenge: Balancing Flexibility and Durability in Design
Using 3D printing, twelve different wing designs were initially created, some of which incorporated structures inspired by the natural veins of monarch butterfly wings. The team examined how these patterns influenced the wings’ agility and efficiency through a series of analyses and experiments. According to lead author Kilian Schäfer, the primary challenge was printing ultra-thin, flexible structures that are still robust enough to withstand stress and strain. The results, published in Advanced Intelligent Systems, demonstrate that larger wings with vein-like structures best meet these requirements.
3D-Printed Magnetic Butterflies: The Robot Wings Inspired by the Efficiency and Adaptability of Monarch Butterfly Wings Enable Precise Movements Without Electronics or Batteries. Photo: TU Darmstadt/Killian Schäfer
According to the researchers, there are numerous potential applications for their invention. In the fields of environmental monitoring and agriculture, “winged” robots could be used to monitor populations of important pollinators like honeybees or assess air quality. They would also be ideal for search-and-rescue operations in hard-to-reach disaster areas, as the wings allow for a small, energy-efficient design. This new approach could also be applied to other shape-shifting, lightweight robots, such as those used in minimally invasive surgery, enabling precise controlled movements.
However, further research is still needed, and the wings themselves must be optimized, explains the second lead author, Muhammad Bilal Khan. In addition to integrated magnetic field generators, the researchers are also exploring how movement and flight paths can be controlled through modifications in the magnetic field.
More Innovation in Robotics: Two years ago, we reported on a robot that can transition between solid and liquid forms. The key here, too, are magnetic fields, as well as the technological metal gallium, which can liquefy at just under 30 degrees Celsius. Similar to the magnetic butterfly wings, numerous potential applications exist, ranging from surgeries and drug delivery to repairs in challenging conditions.