Continuous optical zoom microscopy imaging system based on liquid lenses

Abstract

In this paper, a continuous optical zoom microscopy imaging system based on liquid lenses is proposed. Compared with traditional microscopes, which have discrete magnification, requiring manual conversion of the objective lens to change the magnification, the proposed microscope can continuously change the magnification of the targets in real-time. An adaptive zoom microscope, a liquid lens driving board, a microscope bracket, an adjustable three-dimensional stage and a light source are stacked to form the main framework of the continuous optical zoom microscopy imaging system. The adaptive zoom microscope which is composed of four electrowetting liquid lenses and six glass lenses form the main imaging element of the microscope. By changing the driving voltage which is applied to the four liquid lenses, the focal length of the liquid lenses can be modulated to achieve continuous zooming. By contrast, in traditional microscopes, the zooming process can only be achieved by rotating the eyepieces at different magnifications. At a fixed working distance, the magnification of the proposed microscope can change continuously from ∼9.6× to ∼22.2× with a response time of ∼50ms. Moreover, an axial depth scanning of ∼1000µm can be achieved without any mechanical movement. Our experiments proved that the microscope has stable performance and high consistency during zooming. Therefore, the proposed microscope has obvious advantages over the traditional microscopes in observing dynamic samples with different magnifications and can be commercialized for further expanding the applications in biochemical and pathological analysis.