Remote Axial Tuning in Microscopy Utilizing Hydrogel-Driven Tunable Liquid Lens.

This work presents the use of a tunable-focus thermo-responsive hydrogel based liquid lens in combination with an objective lens to achieve remote axial focusing in a conventional microscopy. The goal of this design is to eliminate image distortion due to sample vibrations caused by mechanical stage scanning. This approach reduces the mechanical complexity and power consumption due to the use of electrically tunable lenses while achieving a two-fold increase in the axial scanning range. The merits of the proposed design were demonstrated by characterizing a customized microscope system over a scanning range of 1700 μm. A lateral resolution of 2 μm was obtained consistently throughout the scanning range. Healthy Spodoptera frugiperda Sf21 insect cells imaging was used to verify the depth scanning ability and the resolution of our remote focusing microscope system.