Strain sensing with sub-micron sized Al-AlOx-Al tunnel junctions

P. J. Koppinen, J. T. Lievonen, M. Ahlskog, I. J. Maasilta

Published 2009-06-23Version 1

We demonstrate a local strain sensing method for nanostructures based on metallic Al tunnel junctions with AlOx barriers. The junctions were fabricated on top of a thin silicon nitride membrane, which was actuated with an AFM tip attached to a stiff cantilever. A large relative change in the tunneling resistance in response to the applied strain (gauge factor) was observed, up to a value 37. This facilitates local static strain variation measurements down to ~10^{-7}.