The researchers also tried to introduce something called "turning bias" in the experiment, which purposely steered the robot buggy the wrong way sometimes, forcing the silkworm moth to frantically adapt and change directions to follow the sexy smell.
But one expert was not overly impressed with the experiment. Jelle Atema, biology professor at Boston University and the Woods Hole Oceaographic Institution, has been studying how animals follow smells underwater for more than 20 years. He and colleagues built a "robo-lobster" in the early 1990s that used smell to detect potential prey.
"It's stunning engineering, but they are doing it in very artificial conditions and I'm not sure what we've learned," Atema said about the paper.
Atema noted that developing an artificial autonomous device that can track smells – as opposed to visual or auditory cues – has proven extremely difficult. That's because of the way smells form plumes and patches in the atmosphere.
"When you look at an odor plume, there are very holes in the concentration. It's not like a smoke plume out of a stack, you see dense concentration that breaks up in patches that drift away with the current. The problem everyone is having is how do animals connect with the plume in the first place."
Atema said by using the fans to blow the pheromone to the moth, it eliminates this key step in the smell-detecting algorithm.
Ando said that he and his colleagues have been studying neuronal mechanisms of the moth brain and trying to reconstruct it into a supercomputer. From there, the idea is to build a sensor "which is an ultimate bottom-up approach to achieve the artificial brain," Ando said. "We also think that the insect-controlled robot will be a 'reference' when we evaluate accuracy of the artificial brain comparing to the real one."
The ultimate goal is to mimic the abilities of the moth.
"If we can increase the performance of the robot by manipulations, more than that of naïve insects, it might be useful for finding odorants for the future," he said.
Atema did have some praise: "I'd like to work with those guys and ask different questions about their robot," he said.