Researchers from Tampere University in Finland and the University of Pittsburgh in the US have created a miniature robot that mimics the aerial motion of falling maple seeds. This innovative robot has potential applications in real-time environmental monitoring and the delivery of small samples in difficult-to-reach areas such as deserts, mountains, cliffs, or the open sea. This technology could revolutionize fields like search-and-rescue operations, studies of endangered species, and infrastructure monitoring.
Wind-dispersed seeds common among maple trees were a key source of inspiration for the light-controlled robot. Image Credit: Jianfeng Yang/Tampere University
At Tampere University, Professor Hao Zeng and Doctoral Researcher Jianfeng Yang are at the forefront of the Light Robots research group, working at the intersection of physics, soft mechanics, and material engineering. They have taken inspiration from nature to design polymeric gliding structures that can be controlled with light.
In collaboration with Professor M. Ravi Shankar from the University of Pittsburgh's Swanson School of Engineering, Zeng and Yang utilized a light-activated smart material to manipulate the gliding behavior of an artificial maple seed. In nature, maple seeds use their samara, or winged dry fruit, to disperse by rotating and gliding gently in the wind. The design of these wings determines their flight path.
The researchers have developed an artificial maple seed that can be actively controlled using light, allowing its dispersal and glide path to be fine-tuned for various trajectories. This innovation could lead to the deployment of microsensors for environmental monitoring or the delivery of small samples, such as soil, in the future.
Hi-Tec Robot Beats Natural Seed in Adaptability
The researchers drew inspiration from the diverse gliding seeds of Finnish trees, each showcasing a unique and captivating flight pattern. They wondered if these natural structures could be replicated using artificial materials to achieve similar graceful flight, but controlled by light.
The tiny light-controlled robots are designed to be released into the atmosphere, utilizing passive flight to disperse widely through interactions with surrounding airflows. Equipped with GPS and various sensors, they can provide real-time monitoring of local environmental indicators like pH levels and heavy metal concentrations.
Jianfeng Yang, Doctoral Researcher, Tampere University
Inspired by natural maple samaras, the team developed an azobenzene-based, light-deformable liquid crystal elastomer capable of reversible photochemical deformation. This innovation allows for precise tuning of the aerodynamic properties.
The artificial maple seeds outperform their natural counterparts in adjustable terminal velocity, rotation rate, and hovering positions, enhancing wind-assisted long-distance travel through self-rotation.
Hao Zeng, Professor, Tampere University
At the beginning of 2023, Zeng and Yang introduced their first dandelion seed-like mini robot as part of the Flying Aero-robots based on the Light Responsive Materials Assembly (FAIRY) project. Funded by the Research Council of Finland, this project commenced in September 2021 and will continue until August 2026.
Whether it is seeds or bacteria or insects, nature provides them with clever templates to move, feed, and reproduce. Often this comes via a simple, but remarkably functional, mechanical design.
M. Ravi Shankar, Professor, Swanson School of Engineering, University of Pittsburgh
“Thanks to advances in materials that are photosensitive, we are able to dictate mechanical behavior at almost the molecular level. We now have the potential to create micro robots, drones, and probes that can not only reach inaccessible areas but also relay critical information to the user. This could be a game changer for fields such as search-and-rescue, endangered or invasive species studies, or infrastructure monitoring,” Ravi Shankar added.
Journal Reference:
Yang, J., et al. (2024) Photochemically responsive polymer films enable tunable gliding flights. Nature Communications. doi.org/10.1038/s41467-024-49108-0.