Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
Sensors (Basel). 2022 Dec 28;23(1):326. doi: 10.3390/s23010326.
Existing displacement sensors of micrometers to sub-micron precision are expensive and have various limitations. This paper reports the design and development of a new contact type compact micro-displacement sensor of sub-micron precision for a fraction of the cost of commercial devices. The basic concept of the new sensor system applies a mechanical magnifying mechanism to magnify a displacement at sub-micron to micron level and uses a low-cost Hall sensor to measure the magnified displacement. Various conceptual designs for the mechanical magnifying mechanism based on cascaded levers with flexural joints were studied and a final design, featuring side-by-side placement of lever structures in a multi-planar layout with adjacent levers coupled by L-shaped coupling foils, was devised. Prototypes of two different sizes and constructions with mechanical magnification ratios over 100 were made and tested. Measurement repeatability and accuracy to sub-micrometer level and a resolution down to hundredths of a micrometer were demonstrated by a compact Alpha Model prototype. Design modification of parts and a corresponding small lot size production procedure were devised to provide an estimated bill of material cost per unit under US$100.
现有的亚微米精度的微位移传感器价格昂贵，且存在各种局限性。本文介绍了一种新的接触式亚微米精度微型位移传感器的设计和开发，其成本仅为商业设备的一小部分。新传感器系统的基本原理是应用机械放大机构将亚微米级的位移放大到微米级，并使用低成本的霍尔传感器来测量放大后的位移。研究了基于带有弯曲关节的级联杠杆的各种机械放大机构的概念设计，并设计了最终的设计方案，该方案采用多平面布局并排放置杠杆结构，相邻杠杆通过 L 形耦合箔片连接。制作并测试了两个不同尺寸和结构的原型，其机械放大倍数超过 100。紧凑型 Alpha 模型原型演示了亚微米级的测量重复性和精度，分辨率可达百分之一微米。对零件进行了设计修改，并制定了相应的小批量生产程序，估计每个单位的材料成本低于 100 美元。
