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.

Freeform Optics可以使用较少的光学组件形成具有较小畸变的高质量图像。目前，自由形式的光学组件的制造非常耗时。按需打印已用于用简单的曲率制造球形或非球形微透镜，但由于对称表面张力力的限制，无法产生更复杂的设计。通过应用外部界面力，可以克服此约束，并且可以形成自由形状。该奖项支持对新型多相打印过程的基本研究，该过程集成了直接打印和界面力，以制造高精度的自由形式微观光学。该项目将通过为低成本和高质量的光学产品提供新的高精度制造工艺来使美国光学行业受益。研究结果可以很容易地应用于使用可调界面力的其他制造区域，例如，在航空航天，汽车和生物医学行业中平滑流线表面的3D打印。研究目标旨在建立镜头表面曲率曲率和多相条件（例如厚度和多相条件（例如厚度和支撑液相）之间的关系（1）； （2）在自由形式透镜曲线和液滴的动态变形之间； （3）在自由形透镜形状和不均匀的材料特性之间（例如，在液滴表面上共存的不同表面张力和粘度）。实验将在混合多相打印平台上进行。在这个平台上，在不同的多相条件下，紫外线可固化的单体液滴将印在固体液体或液体空气多相表面上。精确的线性和倾斜阶段将用于控制支撑液相的厚度和倾斜度。镜头表面曲率将通过白光干涉仪以及搭配的Twyman-Green和Mach-Zhhnder干涉仪进行测量。为了达到第一个目标，在多相表面达到平衡状态后，单体液滴将被固化。有限元方法将用于确定不同多相条件下的透镜曲线曲率。为了实现第二个目标，单体液滴将在瞬态状态下固化。将安装高速相机以识别液滴瞬态形状。将分析在不同瞬态状态下获得的镜头曲线，并与高速图像相关。为了实现第三个目标，将使用无掩模的光刻来调整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