Robot fitted with locust antenna to give it a sense of smell

The sensor sends electrical signals as a response to the presence of a nearby odour, which the robot can detect and interpret.

The researchers from Tel Aviv University connected the sensor to an electronic system and, using a machine learning algorithm, were able to identify odours with a level of sensitivity 10,000 times higher than that of a commonly used electronic device.

“Man-made technologies still can’t compete with millions of years of evolution. One area in which we particularly lag behind the animal world is that of smell perception. When they want to check if a passenger is smuggling drugs [at the airport], they bring in a dog to sniff him,” said Dr Ben Maoz.

“In the animal world, insects excel at receiving and processing sensory signals. A mosquito, for example, can detect a 0.01 per cent difference in the level of carbon dioxide in the air. Today, we are far from producing sensors whose capabilities come close to those of insects.”

Sensory organs, such as the eye, ear and nose, typically use receptors that identify and distinguish between different signals.

These findings are translated into electrical signals, which the brain decodes as information.

The challenge of biosensors is in the connection of a sensory organ, like the nose, to an electronic system that knows how to decode the electrical signals received from the receptors.

“We connected the biological sensor [to the electronic system] and let it smell different odours while we measured the electrical activity that each odour induced,” explained professor Yossi Yovel, a researcher on the project. “The system allowed us to detect each odour at the level of the insect’s primary sensory organ.”

“Then, in the second step, we used machine learning to create a ‘library’ of smells. In the study, we were able to characterise eight odours, such as geranium, lemon and marzipan, in a way that allowed us to know when the smell of lemon or marzipan was presented.

“In fact, after the experiment was over, we continued to identify additional different and unusual smells, such as various types of Scotch whisky. A comparison with standard measuring devices showed that the sensitivity of the insect’s nose in our system is about 10,000 times higher than the devices that are in use today.”

The team said their initial findings suggest the same principle can be used and applied to other senses, such as sight and touch.

“For example, some animals have amazing abilities to detect explosives or drugs; the creation of a robot with a biological nose could help us preserve human life and identify criminals in a way that is not possible today,” Maoz added.

The researchers now plan to give the robot a navigation ability to allow it to localise the odour source and, later, its identity.