In this work, we demonstrate a poly(vinyl chloride) (PVC)-gel-based microlens array (MLA) with tunable focus. The MLA is fabricated using a PVC solution and a glass substrate with a ring-array-patterned electrode. By coating the solution on the substrate and applying a direct current (DC) voltage to the electrode, a PVC gel membrane with a convex surface profile on the inner region of the electrode (anode) is formed with the solvent evaporation. After the complete evaporation of the solvent and removing the voltage, the solidified PVC gel membrane exhibits an MLA character. When an inverse DC voltage is applied to the electrode, the PVC gel accumulated on the inner region will shift toward the outer electrode connected to the anode, leading the curvature of the convex surface to decrease and the focal length to increase accordingly. The variable surface profile with voltage is precisely measured by a laser confocal microscope and the result shows that the focal length of the MLA can be tuned within a large range. 相似文献
The mechanical structures of micro-electro-mechanical systems (MEMS) are composed of different types of microstructures, and their mechanical properties are very important for the realisation and reliability of the system performance. One of the key problems in measuring the mechanical properties is the design and implementation of micro-nano displacement driving mechanisms. This paper describes a mechanism that adopts a two-level loading strategy, fast approach, and precise bending displacement loading structures, and has a theoretical analysis and optimal design based on optimal targets of resistance and displacement. The results show that the relative error is 6.98 % for the fast-approaching structure experiment and its optimal simulation and 4.26 % for the precise bending displacement loading structure (PBLS) experiment and its optimal simulation. The optimised micro-nano displacement loading mechanism can achieve optimal output performance under existing constraints.