Displacement amplification and piezo-sensing in differentially piezo-driven nanopositioners

In this dissertation, we first consider combination of differential-actuation and displacement amplification in flexure-based metallic xy-nanopositioners driven by commercial piezo stack actuators, where a mico-system-analyser (MSA) and commercial capacitive sensors are used for characterization of the nanopositioner. We show that the combination of amplification mechanism and differential actuation provides not only long travel ranges for output stage displacement with displacement amplification gains more than of 11 but also more output displacement linearity compared to linearity of individual piezo stack actuators. We also demonstrate considerable improvement on cross-coupling at the output stage compared to misaligned motions at the inputs. In the second part, we address the problem of direct displacement sensing by commercial piezoelectric ceramics in piezo-driven flexure-based metallic xy-nanopositioners, driven in conventional one-directional (non-differential) actuation modes. In the third part, we address the problem of displacement sensing in differentially-driven metallic xy-nanopositioners actuated by piezo stacks. We consider two types of independent sensors with small footprints, commercial piezoelectric chips and piezoresistive semiconductor strain gauges.