Collaborative Research: Manufacturing of Complex Lenses for Thermal Imaging, Night Vision and Surveillance Systems

超精密机器利用单晶钻石工具制造尺寸精度约为人类头发直径的一小部分(约为一米的十万分之一)的透镜(光学元件)。新的超精密机械技术可以制造几乎任意形状的透镜(光学元件)：自由形状的光学元件。这种自由让镜头设计师可以用全新的方式思考。作为自由曲面光学的使能技术之一，超精密加工有望在光学革命中发挥重要作用。这项技术的一个主要应用领域是制造用于热成像和监视、热成像和夜视系统(红外成像)的透镜。该奖项支持具有成本效益的自由形状红外(热)光学器件制造所需的基础研究。虽然直接影响的领域是红外成像，但这项研究在许多对美国经济至关重要的行业都有更广泛的应用，包括太阳能、医疗保健、生物医学、航空航天和汽车。这项研究跨越了制造、机械工程、材料科学和光学科学等学科。多学科方法将有助于扩大代表不足的群体在研究中的参与，并对工程教育产生积极影响。文献中的报告列举了许多可以通过钻石研磨加工的脆性材料的轶事例子(“钻石可磨削”)，但通常不被认为是“钻石可旋转的”。这种差异可能是由于切割过程的中断或非稳态性质造成的。本研究的目的是验证一种假设，即当金刚石磨削脆性材料时，表面和亚表面的特性不仅取决于金刚石车削时的几何参数，而且还取决于动态非稳态参数，如切入时间和动态变化的切屑厚度。来自北卡罗来纳大学夏洛特分校和俄克拉荷马州立大学的研究人员将设计和构建一个简化的研磨实验，能够隔离和测量不同几何形状的材料的响应，从典型的研磨到高速纳米压痕。表面和亚表面特性将用从原子力显微镜到卢瑟福背散射光谱的各种技术来测量。这项努力将针对由单晶锗和红外透明玻璃制造的红外(IR)光学元件。研究结果不仅将使目标材料的加工效率更高，还将为扩大用于光学和其他应用的“钻石可磨”脆性材料的范围提供科学依据。

Ultra-precision machines utilize single crystal diamond tools to manufacture lenses (optics) with dimensional accuracy that is on the order of a small fraction of the diameter of a human hair (approximately one ten-millionth of one meter). New ultra-precision machine technology enables the manufacture of lenses (optics) of nearly arbitrary shape: freeform optics. This freedom allows lens designers to think in entirely new ways. As one of the enabling technologies for freeform optics, ultra-precision machining is poised to play a major role in an optical revolution. A prime application area of this technology is the manufacture of lenses for thermal imaging and surveillance, thermal imaging and night vision systems (infrared imaging). This award supports fundamental research needed for the cost effective manufacture of freeform infrared (thermal) optics. While the immediate impact area is infrared imaging, the research has broader application to many industry sectors critical to the U.S. economy including solar energy, healthcare, biomedical, aerospace, and automotive. This research crosses the disciplines of manufacturing, mechanical engineering, materials science and optical science. The multi-disciplinary approach will help broaden participation of underrepresented groups in research and positively impact engineering education.Reports in the literature give numerous anecdotal examples of brittle materials that are machinable by diamond milling ("diamond millable") but are not generally considered "diamond turnable". The difference may be due to the interrupted or non-steady state nature of the cutting process. The objective of this research is to test the hypothesis that when diamond milling brittle materials, the characteristics of the surface and subsurface depends not only on the geometric parameters as in diamond turning, but also on the dynamic non-steady-state parameters such as the time-in-cut and the dynamically changing chip thickness. Researchers from UNC Charlotte and Oklahoma State University will design and construct a simplified milling experiment with the capability to isolate and measure the response of materials in different geometries ranging from those typical to milling to high-speed nano-indentation. The surface and subsurface characteristics will be measured with techniques ranging from atomic force microscopy to Rutherford Backscattering Spectrometry. The effort will target infrared (IR) optics manufactured in single crystal germanium and IR-transparent glass. Research results will not only enable more productive machining of the targeted materials, but also provide a scientific basis for expanding the range of "diamond millable" brittle materials for optical and other applications.