Models to determine the process parameters required to sculpt desired micro-feature topographies on flat and curved surfaces using abrasive jet technology

用于确定使用磨料喷射技术在平面和曲面上雕刻所需微特征形貌所需的工艺参数的模型

• 批准号: RGPIN-2014-03895
• 负责人: Papini, Marcello
• 金额: $ 4.23万
• 依托单位: Ryerson University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=638737
• 关键词: Models; determine; process; parameters; required

Jets of small abrasive particles propelled by air or water have been used for many years to modify the topography of engineered surfaces. One of the most important applications of abrasive jet technology (AJT) is as a low cost and rapid micro-fabrication platform for microfluidics, micro-electomechanical systems (MEMS), and opto electronics components. The proposed research will focus on two AJT's for this purpose: air driven abrasive jet micro-machining (AJM) and abrasive waterjet micro-machining (AWJM). The advantages of these technologies are many, but perhaps the most important are that they can machine without creating a heat affected zone, and that they have a unique directional etch capability that most competing technologies do not. For example, traditional isotropic wet etching of channels results in a single basic U-shaped micro-channel cross-section. The directional etch capability of AJT, however, allows the sculpting of many different shapes by changing the process parameters (e.g. jet scan speed and inclination angle, particle size, etc). The proposed research will exploit this unique capability, allowing the technology to be used in the manufacture of novel devices.We have previously developed "surface evolution" models for the AJM of a wide variety of materials that can predict the development of machined topography on an initially flat surface for various combinations of process parameters. The next generation of microfluidic and MEMS devices, however, will require micro-machining 3D (i.e. non-planar) components, an area that has not yet been explored for AJM, despite its great potential. Similarly, there is currently no surface evolution model to predict machined topography using AWJM, a newer process that is fundamentally different than AJM because of abrasive slurry backflow effects and the lack of a mask. Through an exclusive agreement with an industrial partner, we have an AWJM setup with a unique micro-nozzle that will allow us to do ground-breaking research in this area. A complicating factor for AJT is the tendency for particles to embed into the surface and thus affect the surface quality, erosion rate, roughness, etc. Currently, no model exists for predicting what particle and process parameters control the extent of this embedding when machining metals using AJT. The initial portion of the proposed research will focus on addressing these important shortcomings in the modeling of AJT processes. Surface evolution models are important because they can predict machined topography as a function of input process parameters; however, there are currently no techniques to solve the inverse problem, i.e. predicting the process parameters necessary for sculpting particular desired topographies. The final portion of the proposed research will tackle this important problem that would allow the sculpting of particular desired feature shapes using AJT. In other words, we will develop methodologies that allow the inputs (the process parameters) to the surface evolution equation to be determined from a desired solution of the equation at some future time (the desired cross sectional profile). The problem is challenging because the surface evolution partial differential equation is nonlinear and cannot be solved in closed form. Initially, optimization routines will be used to determine the set of parameters that comes closest to a desired topography. Later, novel techniques for sculpting surfaces of desired shapes using combinations of inclined and perpendicular incidence nozzles will developed. These techniques will open up a host of new device design opportunities for the design of 3D MEMS and microfluidics devices, and thus support Canada's growing micro-technology sector.

多年来，人们一直使用空气或水推动的小磨料颗粒射流来改变工程表面的形貌。磨料喷射技术 (AJT) 最重要的应用之一是作为微流体、微机电系统 (MEMS) 和光电子元件的低成本快速微制造平台。拟议的研究将重点关注用于此目的的两种 AJT：空气驱动磨料喷射微加工 (AJM) 和磨料水射流微加工 (AWJM)。这些技术的优点很多，但也许最重要的是它们可以在不产生热影响区的情况下进行加工，并且它们具有大多数竞争技术所不具备的独特的定向蚀刻能力。例如，传统的各向同性通道湿法蚀刻会产生单个基本 U 形微通道横截面。然而，AJT 的定向蚀刻能力允许通过改变工艺参数（例如喷射扫描速度和倾斜角度、颗粒尺寸等）来雕刻许多不同的形状。拟议的研究将利用这种独特的能力，使该技术能够用于制造新颖的设备。我们之前已经为各种材料的 AJM 开发了“表面演化”模型，可以预测机械加工形貌的发展最初是平坦的表面，用于各种工艺参数的组合。然而，下一代微流体和 MEMS 设备将需要微加工 3D（即非平面）组件，尽管 AJM 潜力巨大，但这一领域尚未探索。同样，目前没有表面演化模型可以使用 AWJM 来预测加工形貌，AWJM 是一种较新的工艺，由于磨料浆回流效应和缺乏掩模，与 AJM 根本不同。通过与工业合作伙伴达成的独家协议，我们拥有带有独特微喷嘴的 AWJM 设置，使我们能够在该领域进行突破性研究。 AJT 的一个复杂因素是颗粒倾向于嵌入表面，从而影响表面质量、侵蚀速率、粗糙度等。目前，没有模型可以预测在加工金属时哪些颗粒和工艺参数控制这种嵌入的程度使用 AJT。拟议研究的最初部分将侧重于解决 AJT 过程建模中的这些重要缺陷。表面演化模型很重要，因为它们可以预测加工形貌作为输入工艺参数的函数；然而，目前还没有技术可以解决反问题，即预测雕刻特定所需地形所需的工艺参数。拟议研究的最后部分将解决这个重要问题，允许使用 AJT 雕刻特定所需的特征形状。换句话说，我们将开发允许根据未来某个时间方程的所需解（所需的横截面轮廓）来确定表面演化方程的输入（过程参数）的方法。该问题具有挑战性，因为表面演化偏微分方程是非线性的，无法以封闭形式求解。最初，优化例程将用于确定最接近所需地形的参数集。随后，将开发出使用倾斜和垂直入射喷嘴的组合来雕刻所需形状的表面的新技术。这些技术将为 3D MEMS 和微流体设备的设计带来大量新的设备设计机会，从而支持加拿大不断发展的微技术领域。