Biological sensor allows robot to detect smells

The robot designed by the Tel Aviv University team is able to detect and interpret electrical signals it receives from the biological sensor, as a response to the presence of a nearby odour. 

The biological sensor’s sensitivity to smell is 10,000 times higher than that of existing electronic devices, the researchers said.

“We connected the biological sensor and let it smell different odours while we measured the electrical activity that each odour induced,” said Professor Yossi Yovel, one of the researchers on the team.

“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.”

The scientists were able to characterise eight odours in total, including geranium, lemon and marzipan. After the experiment was concluded, the team continued to test the device, asking it to identify more unusual smells, such as various types of Scotch whiskey.

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In humans and animals alike sensory organs, such as the eye, ear and nose, use receptors that identify and distinguish between different signals. Then, the sensory organ translates these findings 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.

“In the animal world, insects excel at receiving and processing sensory signals,” said Professor Amir Ayali, a member of the research team.

“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.”

In the future, the success of this line of research could pave the way for the technology to be used as a tool for the identification of explosives, drugs, diseases and more.

“The principle we have demonstrated can be used and applied to other senses, such as sight and touch,” said Dr Ben Maoz, another of the study’s authors. “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.

“Some animals know how to detect diseases. Others can sense earthquakes. The sky is the limit.”

In future work, the researchers plan to give the robot a navigation ability to allow it to localise the source of the smell and, eventually, its identity.

The results of the study were published in the journal Biosensor and Bioelectronics.