Research by the Air Force Institute of Technology and Los Alamos National Laboratory demonstrated that measuring the light emission from paint infused with nanomaterials can help identify strain on aircraft parts.  The patent-pending technique was selected as one of the top-two finalists in the Air Force Materiel Command’s 2020 MAJCOM Spark Tank competition (Contributed graphic).
 

Two alumni and one current PhD student from the Air Force Institute of Technology’s Graduate School of Engineering and Management were selected as one of the top-two finalists in the Air Force Materiel Command’s 2020 MAJCOM Spark Tank competition.  Their submission provides an easier and more cost effective technique to measure strain on parts using a nanomaterial based paint.  The team’s submission will compete for the chance to be selected as the final six ideas Air Force wide in December to move to the finals at the Air Force Association Aerospace Warfare Symposium in February.

Spark Tank, a collaboration between AFWERX and the Deputy Under Secretary of the Air Force, Management, is an annual campaign designed to spur and empower innovative ideas from Airmen to further strengthen Air Force culture and capabilities.

The Spark Tank submission team includes 1st Lt. Michael Sherburne (M.S. Electrical Engineering, 2020), 1st Lt. Candice Roberts-Mueller (M.S. Aeronautical Engineering, 2020), and current AFIT PhD student Maj. John Brewer. 

Their submission is based on a patent-pending aircraft diagnostic technique using nanomaterial based paint.  Colloidal quantum dots (CQDs), the nanomaterials used in this research, are infused as a polymer into paint and applied as a thin coating to an aircraft part.  These quantum dots emit a specific wavelength of light when excited by a higher energy light, and when under strain, the dots emit a different wavelength of light.  Using a camera that measures incoming light wavelengths, it is possible to measure the change in strain on the object.  Using CDQs as an optical strain gauge could replace present testing techniques such as digital imaging correlation which can be challenging to setup.

“Maintenance technicians would only need to look at a screen that displays a 2D surface map of the strain, similar to how thermal cameras are used by firefighters to find people within a burning building,” said Sherburne.

Testing the integrity and quality of aircraft structures is becoming more critical as the Air Force’s fleet ages.  However, applications for the patent-pending strain-sensing nanomaterial paint reach beyond aircraft and could be used in any industry requiring an optical strain gauge such as ships, ground vehicles, trains, bridges, and buildings. 

“The benefits for both the Department of the Defense and the civilian sector are many: reduce human error, fast scanning across any surface that the paint adheres to, and the ability to characterize strain on complex 3D printed parts,” said Sherburne.

The Spark Tank submission is based on research completed at AFIT and Los Alamos National Laboratory published in the September 2020 American Chemical Society’s Applied Materials & Interfaces journal.  The article titled Comprehensive Optical Strain Sensing Through the Use of Colloidal Quantum Dots has already been viewed more than 150 times.