Resonant Piezoelectric AlN-actuated Microcantilevers For Detection Of Antigen/Antibody Interactions

Abstract

Resonant microcantilevers are widely spread for different applications, such as atomic force microscopy or biosensor devices. The use of piezoelectric films on top of the cantilevers is a very promising technology due to the possibility of implementing an all electrical actuation/detection scheme. Among the different piezoelectric materials, polycrystalline aluminium nitride (AlN) is a very attractive material as, in contrast to typical alternatives such as lead zirconate titanate or zinc oxide, it is fully compatible with standard silicon technology, what facilitates its integration in silicon-based devices. In this study, our objective is to use sputter-deposited polycrystalline AlN as the actuation material for cantilever-based biosensors and to study the performance of high frequency modes for bio-detection in liquid media. Our results demonstrate a limit of mass detection of 0.07 ng for a 300x200 mu m(2) cantilever in liquid media, which represents a value below the mass of a monolayer of IgG on a 300x200 mu m(2) area.