A new moisture sensor modeled on a camel’s nasal structure can reliably detect variations in humidity.
Known as the ‘ships of the desert’, camels are famed for their ability to survive with little water in their desolate and dry environs. For this reason, their nasal passages make great devices for detecting moisture.
And so, science has once again taken a cue from nature.
According to a study published in the journal American Chemical Society last month, researchers describe the development of a moisture sensor designed using the structure and properties of camels’ noses.
During trials, they found the device could reliably detect variations in humidity in settings from industrial exhaust to the air surrounding human skin.
Compared to camels, the human nose is hardly as skilled at sensing water. People must instead use devices to locate water in arid settings or to identify leaks in industrial facilities.
Sunlight can also interfere with highly sensitive detectors, making them difficult to be used outdoors.
To devise a durable, intelligent sensor that can detect the lowest levels of airborne water molecules, camels’ noses were an ideal muse.
“Narrow, scroll-like passages within a camel’s nose create a large surface area, which is lined with water-absorbing mucus,” said researchers Weiguo Huang, Jian Song and their colleagues in the study.
To mimic the high-surface-area structure within the nose, the team created a porous polymer network. On it, they placed moisture-attracting molecules called zwitterions to stimulate the property of mucus to change capacitance (storage of electrical energy) as humidity varies.
In experiments, the device was durable and could monitor fluctuations in humidity in hot industrial exhaust, find the location of a water source and sense moisture emanating from the human body.
The sensor not only responded to changes in a person’s skin perspiration as they exercised, but it also detected the presence of a human finger and could even follow its path in a V or L shape.
“This sensitivity suggests that the device could become the basis for a touchless interface through which someone could communicate with a computer,” the researchers argued.
“What’s more, the sensor’s electrical response to moisture can be tuned or adjusted, much like the signals sent out by human neurons – potentially allow it to learn via artificial intelligence,” they added.