Soon, smell tracking robots to help in environmental spills

New York: Emulating the scent-tracking behaviour of a silkmoth could help scientists develop robots that are able to sense environmental spills and leaks by smell.
Researchers put a silkmoth in the driver's seat of a small two-wheeled robot to study how the insect tracks down smells.
They chose to use a male silkmoth because of the distinctive mating dance it uses to zero in on a pheromone a chemical signal from its mate, 'LiveScience' reported.
The insect moves in a straight line, followed by zigzagging, a pattern that allows it to detect clusters of odour molecules.
The moth was able to "drive" the robot by walking on a rotating polystyrene ball on-board, like a trackball controlling a computer cursor. The insect drove the robot inside a wind tunnel, which simulated the flow of air the moth would feel if it were flying.
The moth drove upwind to track the pheromone. It successfully located the source of the scent and drove the robot towards it in all initial trials.
When the researchers covered the robot with white paper essentially blindfolding the moth it was still able to reach the target, the pheromone source, about 84 per cent of the time.
Researchers tweaked the robot to make it veer more towards one side. The moth compensated by walking in the other direction on the steering ball, making it to its target about 80 per cent of the time.
When the robot was made to veer to the side and also blindfolded, the moth only found its target 54 per cent of the time. The results suggest the insect was steering by both its sense of smell and its sense of sight.
Researchers also introduced a delay between when the moth sent steering commands – by walking on the ball – and when the robot actually started turning.
The moth's control of the robot worsened gradually when the delay was longer, but it could still drive the robot to the target most of the time.