Fig. 2: Shape and size control of the microlens using liquid shaping technique.
a The contact angles and sizes (in radius and height) of microlenses (illustrated in cross-sections) regulated by the wettability of glass substrate (without physical boundary) while using a constant liquid volume of about 50 nL. b The microlenses of constant 90° contact angle (in cross-sectional view) with their sizes (in radius and height) controlled by the droplet volumes from 5 nL to 800 nL. c Comparison of measured and theoretically calculated radii of microlenses regulated by the liquid volume on the substrates of different wettability (indicated with colors). The green triangle represents the same set of measurements shown in (b). The insets show three representative microlenses of contact angles and radii of about 50°/440 μm, 75°/334 μm, and 90°/277 μm, respectively. Scale bars are 250 μm. d Cross-sectional profiles of spheroid microlenses made on a substrate of a circular boundary (i.e., a radius of 493 μm). e Cross-sectional profiles of ellipsoid microlenses fabricated on a substrate of an elliptical boundary (i.e., a semi-major length of 460 μm and a semi-minor length of 360 μm), the shapes and sizes of microlenses are displayed on both x-z (colored solid lines) and y-z planes (colored dashed lines). f Study of the shrinkage effect in microlenses (in terms of contact angle and volume) by comparing their cross-sectional profiles before (colored solid lines) and after (colored dotted lines) ultraviolet light-induced polymerization. The shrinkage ratio is calculated using (V1-V2)/V1, where V1 and V2 are the lens volume before and after polymerization.
