三軸閉迴路奈米定位致動系統之設計開發與特性研究

Abstract

高精度定位平台伴隨精密科技之發展，奈米級解析度的定位平台更扮演了奈米科技發展之重要角色。本論文以壓電元件作為致動系統，而以全像術DVD讀取頭做為量測系統，開發三軸定位平台。壓電元件常被運用到微米以下的致動器上，經由精確的電壓控制亦可獲得奈米級的位移解析，但最大行程卻受限於其幾何尺寸。為了擴大致動行程，本論文採用無背隙之撓性結構來放大壓電元件之行程，並透過理論分析以及軟體模擬來探討行程放大效果與撓性結構幾何外形之關係。為了迎合致動行程之放大，像散式位移量測系統也利用改變物鏡焦長方式，來提昇其位移量測範圍。除此之外，並採用體積極為緊緻的全像光碟機讀取頭作為位移感測器，使整體系統體積更多縮小，更有力於奈米定位平台之運用和推廣。定位平台之行程、線性誤差、重現性誤差及解析度等特性也透過實驗測試方式予以驗證。

High-resolution position stage is the footstone of the precision technology. A nano-level resolution positioning stage plays a important role in the development of nanotechnology. This paper proposes a 3-axis positioning stage built up by piezoelectric actuators as the actuating system and HOE-DVD pickup head as the displacement measurement system. Piezoelectric units are often used in micro-level actuator; by using the precise voltage control piezoelectric units can also fulfill a nano-level actuation. In order to increase the stroke of piezoelectric actuator, a flexible structure without backlash and friction is utilized. Its relationship between the displacement amplifying effect and the geometric parameters of flexible structure is studied by the theoretical analysis and the finite element analysis. For matching the actuation stroke, the optical displacement measurement system is modified by varying focal length of the lens. Besides, the elaborate application of the miniature HOE pickup head makes the whole system more compact to promote the widespreading application of the nano-level positioning systems. Furthermore, diverse properties of the positioning stage including stroke, linearity, repeatability and resolution are verified by experimental testings.