Characterizing piezoscanner hysteresis and creep using optical levers and a reference nanopositioning stage.

International audienceA method using atomic force microscope (AFM) optical levers and a reference nanopositioning stage has been developed to characterize piezoscanner hysteresis and creep. The piezoscanner is fixed on a closed-loop nanopositioning stage, both of which have the same arrangement on each axis of the three spatial directions inside the AFM-based nanomanipulation system. In order to achieve characterization, the optical lever is used as a displacement sensor to measure the relative movement between the nanopositioning stage and the piezoscanner by lateral tracking a well-defined slope with the tapping mode of the AFM cantilever. This setup can be used to estimate a piezoscanner's voltage input with a reference displacement from the nanopositioning stage. The hysteresis and creep were accurately calibrated by the method presented, which use the current setup of the AFM-based nanomanipulation system without any modification or additional devices

High Coupling Factor Piezoelectric Materials for Bending Actuators: Analytical and Finite Elements Modeling Results

Abstract: New giant piezoelectric factor materials such as PMN-PT and PZN-PT were researched during the last decade and are actually becoming commercially available. As they seem very attractive for actuator designs, we studied their potential in replacing PZT ceramics. In a first comparative approach, we tested a series of classic rectangular composite bimorph structures of different combinations of thicknesses. The goal consisted in evaluating the quantitative improvement in terms of maximum displacement range and blocking force value. The resulted ratio is situated between 3 to 5. Given the very high coupling factor of PMN-PT and PZN-PT that may reach 0.97 (the PZT ranges around 0.3), we noticed large differences between the existing analytical results and the finite elements simulations performed under COMSOL Multiphysics, which finally, for this type of materials, proved to be much more reliable

Development of a Modular and Compliant Microassembly Platform with Integrated Force Measurement Capabilities

There are many challenges associated with microassembly that are not present in macro-assembly such as poorly understood interactions and difficulty in taking measurements at th