A group of scientists at Washington University in Missouri re-engineered the olfactory system of grasshoppers as biological bomb detectors, according to a report.
Insects have olfactory receptor neurons in their antennae that detect chemical odors in the air. These neurons send electrical signals to a part of the insect brain called the antennal lobe.
The antennae of grasshoppers have approximately 50,000 of these neurons.
During the experimentation, the team puffed explosive materials unto the grasshopper’s antennae. It included vapors of trinitrotoluene (TNT) and its precursor 2,4-dinitrotoluene (DNT).
They also include non-explosives such as hot air and benzaldehyde.
Scientists implanted electrodes into the antennal lobes of grasshoppers. They observed neurons being activated upon exposure to the explosive.
Meanwhile, observations show electrical signals can tell explosive vapors apart from non-explosives.
Later on, the team put a tiny, lightweight sensor backpack in the grasshopper. It will record and wirelessly transmit electrical activity of the insect’s antenna lobe in an instant.
The experiment successfully detected explosives up to seven hours after they implanted the electrodes before the insects experienced fatigue and died.
Researchers also yielded an average accuracy of detection up to 80%.
US Office of Naval Research funded the project. The team believes that this study will be applicable in cases of great interest to homeland security.