These Maple Seed-Inspired Twirling Robots Can Deliver Sensor Packages to the Most Remote Locations
Twirling on the wind like their natural counterparts, these tiny aerial robots can be steered using light.
A team of researchers from Tampere University and the University of Pittsburgh have created a tiny robotic sensor designed to provide environmental monitoring in hard-to-reach locations — by taking inspiration from twirling maple seeds.
"The tiny light-controlled robots are designed to be released into the atmosphere, utilizing passive flight to disperse widely through interactions with surrounding airflows," explains Jianfeng Yang, a doctoral researcher at Tampere University and first author on the work. "Equipped with GPS and various sensors, they can provide real-time monitoring of local environmental indicators like pH levels and heavy metal concentrations."
Sensing these kinds of environmental conditions is relatively easy; harder is distributing the sensors where they need to go. Aerial dispersion can fix that problem, if the sensor platform is light enough — but then you've no way to control where it goes. The team's take on the problem solves this, allowing the flying sensors to be roughly steered using light — and their shape is inspired by the humble maple seed, though experiments were also carried out with variants mimicking the Javan cucumber seed and dandelion seeds.
"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," claims Hao Zeng, Tampere University professor and corresponding author on the work, in which the team produced the robots from an azobenzene-based liquid crystal material that deforms when exposed to light.
"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," notes co-author M. Ravi Shankar.
"Thanks to advances in materials that are photosensitive," Shankar continues, "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."
The team's work has been published in the journal Nature Communications under open-access terms.
Main article image courtesy of Jianfeng Yang/Tampere University.