Passive Detection of Damage and Strain in Aerospace Composites

MesoScribe Technologies proposes to apply a newly developed Direct Write conformal electronics fabrication technology to pattern sensor arrays directly onto composite aircraft structures with suitable polymer protective coatings. This will produce robust, well bonded, structurally sound and environmentally protected elements, which can sustain the harsh environments associated with aircraft operation. The passive sensor arrays can be distributed over the structure and interrogated by ground personnel to asses strain and cracking in fiber filled polymer composites. An additional embodiment of the technology will allow protecting/camouflaging the sensor elements within a coating, which can be either a paint appliqué or a high performance thermal sprayed liquid crystalline polymer coating. This will be achieved in a completely passive mode with little or no disturbance or impact to the airframe structure. The measurement will rely on all passive strain and damage detection using custom tunable RF elements and conductor patterns. The RF circuit can be applied conformally onto the aircraft structure, either in the field or at the depot level using portable tools and coupled with non-contact measurement concepts which will measure damage through frequency shifts. There will be no power or active electronics involved with the whole system which is made portable, easy to use and at low cost.