A silk moth has "piloted" a robot to track down a scent.
In a study conducted by researchers from the University of Tokyo and published in the journal Bioinspiration and Biomimetics, silk moths used a robot to track down emitted sex pheromones.
The silk moth was chosen to drive the robot because of its distinctive mating dance, an intricate combination of straight lines, zig zags, turns and loops. The moth was attached to a polystyrene ball that controlled the movement of the two wheeled robot, in a manner similar to a computer mouse. The robot used two 40 mm fans that blew pheromone-laced air at the moth. The experiment took place in a 1800 mm wind tunnel, with the emitted pheromone air and the moth robot at opposite ends of the tunnel.
All of the 14 silk moths were able to successfully navigate the robot to the pheromone source.
"The simple and robust odor tracking behavior of the silkmoth allows us to analyze its neural mechanisms from the level of a single neuron to the moth's overall behavior," said Noriyasu Ando, lead author of the study. "By creating an 'artificial brain' based on the knowledge of the silkmoth's individual neurons and tracking behavior, we hope to implement it into a mobile robot that will be equal to the insect-controlled robot developed in this study."
The study also introduced a turning bias in the experiment, changing the power of one of the wheel, so the robot veered to one side. The silk moths were quickly able to adapt to this change. "The best way to elicit adaptive behaviors of insects is to put them into extraordinary situations," Ando explained to Institute of Physics. "The turning bias in our study is analagous to a situation in which we try to ride unbalanced bicycles. We need training to ride such bicycles smoothly but the silkmoth overcomes the situation with only simple and fast sensory-motor feedbacks."
When a robot tracks an odor continuously (what the silk moth performed in these experiments), a fast response time is vital. This research could prove very helpful to developing robots to search and detect chemical spills or leaks.
