Development of an Evanescent Microwave Probe Scanner for Detecting and Assessing Corrosion Beneath Painted and/or Sealed Surfaces

The corrosion of airframe structures is a serious problem that has economic, performance and safety consequences for both military and civilian fleets. The detection and repair of corrosion in airframe structures is time consuming and leads to delays inaircraft availability, hence, hindering the mission of the Air Force. Through the use of evanescent microwave probes (EMP), it is possible to image the onset of corrosion in large areas of metals and alloys used in military aircrafts. The use of EMPs has many advantages: i) it is already demonstrated that it detects the onset of corrosion in aluminum alloys, ii) owing to its very high operation frequency, the EMP can be scanned at a very fast speeds (> 1cm/s) over the structure,iii) EMP arrays can be used to further reduce the scan time over very large structures. To realize this ability, we will construct suitable EMP arrays for imaging corrosion, enhance the array performance by making them wireless, and install these wireless arrays on micro-robots that will traverse the surfaces of large structuresautonomously. The micro-robots equipped with EMP arrays will report their findings to a central processing unit upon discovering corroded regions. This will allow for the development of easily diagnosed images describing the severity of the corrosionfound, as well as its exact location, thus saving the Air Force an estimated $5 million in maintenance and repair. MICC is interested in a variety of wireless non-destructive evaluation and imaging systems and the proposed study will enable it to move into many