Design, Fabrication And Characterization Of PDMS-Based Microlens Arrays

A major trend in the development of microelectromechanical systems?MEMS?is the combination of optics to form micro-optical electromechanical systems?MOEMS?,and the development of micro-optical electromechanical systems is inseparable from microoptics supports.As an important part of micro-optical components,microlens arrays have become indispensable in imaging,sensing,point source devices and optical interconnects.The PDMS-based magnetorheological elastomer film is obtained by mixing nano-magnetic particles into a PDMS matrix and forming a thin film with a micron-thickness thickness by a special method.Our research team has prepared and tested this film.The results show that the optical properties of the film will change under the action of external magnetic field.Based on those results,two PDMS microlens arrays were firstly designed,fabricated and characterized.Then,the existing microlens array manufacturing method was combined with PDMS-based magnetorheological elastomer optical film.Finally,a novel PDMS-based magnetic response microlens array was innovatively designed.The first is a PDMS thin film microlens array whose main principle is to use a mechanical deflection to transform a planar film into a microlens array structure.The groove extrusion film model was theoretically analyzed and the deformation profile of the film section was obtained by ANSYS simulation.The fabrication method of PDMS thin film microlens array was designed.The PDMS thin film microlens array was fabricated by SU-8 thick lithography and spin coating process.The prepared samples were geometrically characterized and optically tested which obtains good test results.Then,a novel method of fabricating microlens array is described in this paper.We have successfully fabricated SU-8 microlens array die and PDMS microlens arrays by utilizing the liquid surface morphology formed by the liquid phase in contact with the microstructured surface.The liquid surface topography under different wetting models was analyzed and the Cassie model was determined to be an ideal model for forming microlens array die.In order to ensure that the liquid SU-8 and PDMS surface microstructures are in the Cassie wetting model,the influence of the geometric parameters of the PDMS surface microstructure is analyzed and the contact method of the inverted buckle is adopted.The prepared samples were geometrically characterized and optically tested which obtains good test results.Finally,this paper will initially design and fabricate a magnetically responsive microlens array based on a PDMS magnetorheological elastomer optical film.The magnetic response mechanism of PDMS magnetorheological elastomer optical film is introduced.The magnetic properties of a PDMS-Fe₃O₄ magnetic response optical film are discussed.Based on the preparation method of the photoresist die in this paper,a PDMS-based two-layer structure magnetically responsive microlens array of horizontal chain structure and vertical chain structure was designed and prepared.The characterization of the prepared two kinds of magnetic response microlens arrays shows that the quality of the lens array structure is good and the imaging is clear,and the horizontal chain structure is clearer than the vertical chain structure,and the method for improving the optical performance of the magnetic response microlens array is reduce particle aggregation.A PDMS-based magnetically responsive thin film microlens array was designed by using PDMS-Fe₃O₄ magnetically responsive optical thin film optical film.