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
μ
m 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
μ
m and observe the object in different depths. This article provides a new approach for the design of a MOS.