wind tunnel flight test
Hair sensors are now being tested in wind tunnels like this one Central Press/Getty Images

Engineers from the Air Force Research Laboratory (AFRL) in Ohio, US have developed artificial hair sensors that could soon to change the course of an agile flight.

The inspiration for this design was taken from bats and insects like crickets. Dr Jeff Baur, principal engineer- Structural Materials Division, Materials and Manufacturing Directorate - spoke of how crickets stop chirping when a person enters the room because they can feel air disturbances through hairs on their body that can sense changes in the environment.

A similar approach led the "Artificial Hair Sensor" team funded by the Air Force Office of Scientific Research to develop sensors that look like hairs over the surface of aircraft.

These hairs, the team claims, make real time measurements during flight and detect changes in the air helping jets "fly by feel".

Measurements on aircraft that deal with agile flight are now done with large, bolted on sensors that measure from only one point on the aircraft and reportedly offer measurements with "delayed sensing".

Hair sensors are made of carbon nanotubes grown inside glass fibre capillaries. Each "hair" has an electrode on either end of the glass capillary and with a diameter of less than one-tenth a human hair, it is highly sensitive.

When there are changes in airflow, these nanotubes get compressed, causing differences in resistance between electrodes.

An AI is then able to read these changes and output them as readings which engineers can use to build systems that make aircraft agiler during flight.

"These can help to better understand aerodynamics or wind gusts in an urban environment, for example. Imagine my agile aircraft is turning the corner of a building—the wind may change. If I have a system that can detect a gust is coming, I can adjust immediately to stay on course," said Dr Greg Reich, a team member from the Aerospace Systems Directorate.

Hair sensors have so far been able to detect wind speeds up to 100mph by making small changes in the capillary's diameter, says Baur. This research has so far resulted in three Patent applications, according to the publication.

The sensor system is still in its proof of concept stage but is reportedly sought after by various aerospace researchers and companies to integrate into to their wind tunnel and design systems.