| Micro-lenses, as well as micro-lens arrays, have been widely used and attracted attention in miniature optical systems in recent decades. However, the fabrication methods for micro-lenses and lens arrays are limited. In this research, three rapid and low-cost manufacturing methods for micro-lenses and lens arrays are presented. For all three methods, micro-lenses and lens arrays were formed in multiphase systems. They are the results of a balance of multiple forces, including force of gravity, interfacial tension force, buoyancy, and electrical force. The first method is the printing technique assisted method, or PTA method. This method is able to produce high-quality biconvex micro-lenses with controllable size and shape using low-viscosity UV-curable materials. The second method is the micro-fluidic dispenser assisted method, or MDA method. This method can generate near spherical or drum shaped micro-lenses and lens arrays using UV-curable materials with different viscosities. The third method is the spin coating technique assisted method, or SCTA method. It is able to fabricate micro-lens arrays using thermally curable materials with different viscosities. These technologies can significantly simplify the production processes and reduce the cost for manufacturing micro-optics. In this research, we also conducted a numerical simulation for PTA method. We proposed a numerical method using a combination of the Young- Laplace equation, and Navier-Stokes equation as governing equations. Followed a selection based on force balance and mass conservation. We also developed a program using MATLAB to simulate the shape of the biconvex lens formed using the printing technique assisted method. We used this numerical simulation to explore the influence of different forming parameters, such as droplet volume, material density, and interfacial tensions on the size and shape of the formed lens. Overall, this research demonstrated that these three micro-lens manufacturing methods have the merits of rapid fabrication, low-cost, and resulting lenses with desirable properties. These experimental and numerical methods will significantly simplify the manufacturing process of micro-lenses and lens arrays and greatly expand the potential for polymeric optics implementation. |
