小 型 壓 電 步 行 機 器 之 分 析 與 實 驗

Abstract

溯自1969年發現有明顯壓電效應的PVDF材料迄今，已經廣泛使用於各種不 同的領域，諸如：樑臂的振動控制、海底聲納探測器、醫學的血壓測量儀 器、機器人的人工感測皮膚等，這些應用包含了振動、聲學、醫學儀器及 機器人等各種範疇。它有這麼多的發揮空間，歸因於它的材料性質的特點 ：柔軟、撓性大、低聲音阻抗、和輕質量。因此不同於陶瓷壓電材料。本 研究旨在利用其特點製作小型壓電步行機器，著重於小型壓電步行機器的 因次分析之探討、製作過程、和行走速度的實驗。首先，分析彎曲形狀的 壓電片之振動狀態，以計算共振頻率和瞭解彎曲情況。目的是當小型壓電 機器在共振頻率時，可以使得其行走速度達到最大值。由於小型機器的運 動狀態模式不易建立，因此利用因次分析和相似方法得到模式定律以取代 系統的運動方程式。並探討當小型壓電機械其尺寸等比例縮小但材料性質 不變時，對於行走速度快慢的影響。最後，利用得到的模式定律與實驗結 果相互驗證。 The exploration of PVDF applications has increased in different fields, for instance, cantilever beams vibration, underwarter sonar detector, medical blood pressure measurement instrument, robotics artificial sensitive skin, etc. Due to properties of softness, flexibility,low acoustic impedance, and light weightness, it can be developed and designed in numerous fields. Taking advantage of PVDF material to fabricate micro- walking machines, this study presents dimensional analysis, fabrication process, and walking experiments. The curved piezo bimorph is first analyzed for vibration behaviors in order to compute resonant frequencies and bending deflections. When the micromachine is excited at resonant frequencies, its walking speed may reach a maximum value. Since behaviors of micromachines are not amenable to modeling, both dimensional analysis and similarity method are carried out to obtain model laws. Furthermore, micromachines are scaled down in geometric sizes in walking experiments. Model laws serve to verify the experimental results that are primarily concerned with walking speeds.