Locusts inspire low-power collision detector

Plagues of locusts are made up of millions of insects that avoid bumping into one another thanks to their inbuilt Lobula Giant Movement Detector (LGMD), a specialised collision avoidance neuron.

Locust brain inspires robot navigation system

According to Darsith Jayachandran, graduate student in engineering science and mechanics at Penn State University, the neuron receives two different signals. An image of an approaching locust falls on the avoiding locust's eye. The closer the invading locust gets, the larger the image and the stronger this so-called excitation signal becomes. The other input is the change in angular velocity of the invading locust with respect to the avoiding locust.

"Because the neuron has two branches, the locust computes the changes in these two inputs and realises that something is going to collide," Jayachandran said in a statement. "So the avoiding locust changes direction."

According to Penn State, the researchers developed a compact, nanoscale collision detector using monolayer molybdenum sulphide as a photodetector. They placed the photo detector on top of a programmable floating gate memory architecture that can mimic the locust's neuron response using only a small amount of energy.