Development of a Multifunction Piezoelectric Microscopic Observation System Based on Visual Feedback

Microscopic observation system (MOS) is a basic instrument in the fields of biomedical and micronano manipulations. Here, A multifunction piezoelectric microscopic observation system (MPMOS) based on the visual feedback is proposed, which has functions of automatic focusing, cell counting, cell localization and wide range scanning. A focusing mechanism combined with a lead zirconate titanate (PZT) stack and a rhombus amplifying mechanism (RAM) is integrated in the MPMOS, which has the motion stroke of 359.6 μm and the displacement resolution of 30 nm. The MPMOS adopts an image sharpness evaluation function based on Laplace operator and an in-focus position searching algorithm combining coarse tuning and fine-tuning processes. The focusing time is less than 3.36 s and the focusing success rate is better than 94%. The applications are carried out, which includes the automatic focus and microscopic observation of both transparent and opaque objects, the red blood cells counting and locating, the range of 350 μm and observe the object in different depths. This article provides a new approach for the design of a MOS.