A Multiphase Printing Process for Freeform Optics Manufacturing

自由曲面光学制造的多阶段打印工艺

• 批准号: 1538439
• 负责人: Lei Li
• 金额: $ 29.9万
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1538439&HistoricalAwards=false
• 关键词: Multiphase; Printing; Process; Freeform; Optics

Freeform optics can form high quality images with smaller aberrations by using fewer optical components. At the present time, fabrication of a freeform optical component is extremely time consuming. Drop-on-demand printing has been used to fabricate spherical or aspherical microlenses with simple curvatures, but is not able to produce more complicated designs due to the constraint of symmetric surface tension forces. By applying external interfacial forces, this constraint can be overcome and freeform shapes can be formed. This award supports fundamental research of a novel multiphase printing process that integrates direct printing and interfacial forces in order to fabricate high precision freeform micro optics. This project will benefit the U.S optical industry by providing a new high precision manufacturing process for low-cost and high quality optical products. Research results can be readily applied to other manufacturing areas that utilize tunable interface forces, for example, 3D printing of smooth streamline surfaces in aerospace, automobile, and biomedical industries.The research objectives are to establish relationships (1) between lens surface curvatures and the multiphase conditions (such as thickness and tilting of the supporting liquid phase); (2) between freeform lens profiles and dynamic deformation of droplets; and (3) between the freeform lens shapes and non-uniform material properties (e.g. different surface tension and viscosity coexisted on the droplet surface). Experiments will be conducted on a hybrid multiphase printing platform. On this platform, ultraviolet curable monomer droplets will be printed on a solid-liquid-air or liquid-air multiphase surface under different multiphase conditions. A precision linear and tilting stage will be used to control the thickness and tilting of the supporting liquid phase. Lens surface curvatures will be measured by a white light interferometer and a combined Twyman-Green and Mach-Zehnder interferometer. To achieve the first objective, monomer droplets will be cured after the droplets reaching equilibrium status on the multiphase surface. Finite element method will be used to determine lens profile curvatures under different multiphase conditions. To achieve the second objective, monomer droplets will be cured at transient state. A high speed camera will be installed to identify the droplet transient shape. Lens profiles obtained at different transient state will be analyzed and correlated to high speed images. To achieve the third objective, maskless lithography will be used to tune the local surface tension and viscosity of the monomer droplet to achieve non-uniform properties, which will cause non-uniform droplet deformation.

自由曲面光学器件可以使用更少的光学元件形成像差更小的高质量图像。目前，自由曲面光学元件的制造极其耗时。按需滴墨打印已用于制造具有简单曲率的球面或非球面微透镜，但由于对称表面张力的限制，无法生产更复杂的设计。通过施加外部界面力，可以克服这种限制并可以形成自由形状。该奖项支持新型多相印刷工艺的基础研究，该工艺集成了直接印刷和界面力，以制造高精度自由曲面微光学器件。该项目将为低成本、高品质的光学产品提供全新的高精度制造工艺，使美国光学工业受益。研究成果可以很容易地应用于利用可调界面力的其他制造领域，例如航空航天、汽车和生物医学行业中光滑流线型表面的 3D 打印。研究目标是建立透镜表面曲率和透镜表面曲率之间的关系 (1)多相条件（例如支持液相的厚度和倾斜）； (2) 自由形状透镜轮廓与液滴动态变形之间； （3）自由曲面透镜形状与不均匀材料特性（例如，液滴表面共存不同的表面张力和粘度）之间的关系。实验将在混合多相打印平台上进行。在此平台上，紫外线固化单体液滴将在不同的多相条件下打印在固-液-空气或液-空气多相表面上。将使用精密线性和倾斜平台来控制支撑液相的厚度和倾斜。透镜表面曲率将通过白光干涉仪以及组合的 Twyman-Green 和 Mach-Zehnder 干涉仪进行测量。为了实现第一个目标，单体液滴在多相表面达到平衡状态后将被固化。有限元方法将用于确定不同多相条件下的透镜轮廓曲率。为了实现第二个目标，单体液滴将在瞬态下固化。将安装高速摄像机来识别液滴瞬态形状。将分析在不同瞬态下获得的镜头轮廓并将其与高速图像相关联。为了实现第三个目标，将使用无掩模光刻来调节单体液滴的局部表面张力和粘度，以实现不均匀的特性，这将导致不均匀的液滴变形。

项目成果

Manufacturing PDMS micro lens array using spin coating under a multiphase system

• DOI: 10.1088/1361-6439/aa68c8
• 发表时间: 2017-05-01
• 期刊: JOURNAL OF MICROMECHANICS AND MICROENGINEERING
• 影响因子: 2.3
• 作者: Sun, Rongrong;Yang, Hanry;Li, Lei
• 通讯作者: Li, Lei