PITA Fiscal Year 2010 Projects - Innovative Infrastructure Systems

Aluminum nitride deposition for self-sensing in aluminum products

Principal Investigators: Irving Oppenheim, David W. Greve

Structural sensing is mandatory during the development of high performance materials such as advanced hybrid aluminum composites; moreover, users such as aircraft manufacturers increasingly seek to implement lifetime structural health monitoring of their products. However, transducer attachment and wiring represent significant limitations, often prohibitive, to structural sensing and structural health monitoring. The proposed project will revolutionize the technology for aluminum products by depositing onto the structural panel a thin film of aluminum nitride, a piezoelectric material suitable for structural sensing, followed by a thin-film surface electrode and interconnect layer. That is, the structural sensors and their conductors will be integrated with the aluminum material. Other researchers have shown that aluminum nitride thin films can be deposited on various substrates, in some cases to construct acoustic wave devices, but our project will be the first to do so for aluminum alloy products such as used in aircraft manufacture. In this project we will construct a small portable apparatus for sputter deposition on large flat panels, we will develop the process for reactive sputtering of the aluminum nitride transducer material on aluminum alloy panels, and we will characterize the piezoelectric material properties.