Individually, ants have only so much strength and intelligence. However, as a colony, they can use complex strategies to complete sophisticated tasks and evade larger predators. Applied to robotics, this phenomenon could prove useful in unknown environments - such as search and rescue missions - according to researchers at the École Polytechnique Fédérale De Lausanne (EPFL). They outline their inspiration for the innovative technology and explain its uses.
Researchers Zhenishbek Zhakypov and Jamie Paik in their lab, holding tribots. Photo: Marc Delachaux|EFPL
The tiny robots, called Tribots, display minimal physical intelligence on an individual level but are able to communicate and act collectively, just as the trap-jaw ant does. Despite being simple in design and weighing only ten grams, each robot has multiple locomotion modes to navigate any type of surface. Collectively, they can quickly detect and overcome obstacles and move objects much larger and heavier than themselves.
Inspired by trap-jaw ants
The three-legged, T-shaped origami Tribots can be assembled in only a few minutes by folding a stack of thin, multi-material sheets, making them suitable for mass production. The robots are already equipped with infrared and proximity sensors for detection and communication purposes. However, as they are completely autonomous and untethered, they could accommodate even more sensors if necessary.
The tribots have five locomotion strategies, enabling them to navigate tricky terrrain. Image: Zhenishbek Zhakypov|EFPL
Zhenishbek Zhakypov, one of the researchers at EPFL, explains the Tribot’s model: “Their movements are modelled on those of Odontomachus ants. These insects normally crawl, but to escape a predator, they snap their powerful jaws together to jump from leaf to leaf.” The Tribots replicate this catapult mechanism through an elegant origami design that combines multiple shape-memory alloy actuators. As a result, a single robot can produce five distinct locomotion gaits: vertical jumping, horizontal jumping, somersaulting to clear obstacles, walking on textured terrain and crawling on flat surfaces - mimicking the creatively resilient ants.
Roles: leader, worker and explorer
Despite having the same anatomy, each robot is assigned a specific role depending on the situation. 'Explorers' detect physical obstacles in their path, such as objects, valleys and mountains. After detecting an obstacle, they inform the rest of the group. Then the 'leader' gives the instructions while the 'workers' pool their strength to move objects. “Each Tribot, just like Odontomachus ants, can have different roles. However, they can also take on new roles instantaneously when faced with a new mission or an unknown environment, or even when other members get lost. This goes beyond what the real ants can do,” says Professor Jamie Paik.
In practical situations, such as an emergency search mission, Tribots could be deployed en masse. And thanks to their multi-locomotive and multi-agent communication capabilities, they could locate a target quickly over a large surface, without relying on GPS or visual feedback. “Since they can be manufactured and deployed in large numbers, having some 'casualties' would not affect the success of the mission,” says Paik.
He adds: “With their unique collective intelligence, our tiny robots can demonstrate better adaptability to unknown environments; therefore, for certain missions, they would outperform larger, more powerful robots.”
The article, Designing Minimal and Scalable Insect-Inspired Multi-Locomotion Millirobots by Zhenishbek Zhakypov, Kazuaki Mori, Koh Hosoda and Jamie Paik, was first published in Nature on July 10, 2019.