Tunnel junction based displacement sensing for nanoelectromechanical systems

Abstract

We demonstrate the feasibility of using normal state Al-AlOx-Al tunnel junctions for displacement sensing. The experimental setup consisted of tunnel junctions fabricated on a thin silicon nitride membrane, which was actuated with an AFM tip. Advantages of tunnel junction detectors are their small size, relatively high gauge factor, existing high frequency read-out schemes, and ease of integration with the mechanical system. In addition, Al-AlOx- Al junctions can be used for displacement sensing in zero magnetic field, unlike sensors based on magnetic tunnel junctions. © 2007 IOP Publishing Ltd.