Atomic force microscope cantilevers with integrated actuation and sensing on the chip level provide several distinct advantages over conventional cantilever instrumentation. These include clean frequency responses, the possibility of down-scaling and parallelization to cantilever arrays as well as the absence of optical interferences. However, the two major difficulties with integrated transduction methods are a complicated fabrication process, often involving a number of fabrication steps, and a high amount of feedthrough from actuation to sensing electrodes. This work proposes two hybrid cantilever designs with piezoelectric actuators and piezoresistive sensors to reduce the actuator to sensor feedthrough. The designs can be realized using a commercial microelectromechanical systems fabrication process and only require a simple five-mask patterning and etching process. Finite element analysis results are presented to obtain modal responses, actuator gain and sensor sensitivities of the cantilever designs.
Dr Michael Ruppert received the Dipl.-Ing. Degree in automation technology from the University of Stuttgart, Germany, in 2013 and the Ph.D. degree with excellence award in Electrical Engineering from The University of Newcastle, Australia where he is currently a Postdoctoral Researcher with the School of Electrical Engineering and Computing. His research interests include control, estimation and self-sensing of microelectromechanical (MEMS) systems such as piezoelectric microcantilevers and nanopositioning systems for multifrequency and single-chip atomic force microscopy.