Fabrication of stacked polymer and metal multilayer on flexible tactile sensor

• Main Authors: Chih-Chang Wu, 吳志昌
• Other Authors: Chen-Kui Chung
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/14764255123326441296

碩士 === 國立成功大學 === 奈米科技暨微系統工程研究所 === 95 === Tactile sensors are widely applied in electro-mechanic and bio-medical field. The aim of this study is designing the tactile sensor by stacking polymer and metal multilayer on polymer substrate in MEMS. A novel sensor design is presented that process omits bulk machining or sacrificial layer releasing. Therefore, complicated fabrication steps are reduced. The feasibility of designed device is verified by finite element software and simulation results could be the references for deciding the size of sensor. Polymer surfaces are generally associated with poor adhesion and wettability which are defects regarding stack and metallization of polymers. So the technique of surface modification by using O2 plasma is utilized to enhance the moistness of polymer surface and surface energy. According to three measured liquid contact angles and Lifshitz-van der Waals/Lewis acid-base approach method, the variation of polymer surface energy can be described. Besides, the Titanium electrode which is sputtered on PDMS surface would crack easily due to thermal stress effect. For this reason, there are two methods to improve questions in this thesis. First, Au which has good ductility is utilized to be the seed layer and the pattern of electrode is defined by photolithography. Then Au thin film wrinkle induced by internal force can be improved by Ni electroplating. Moreover, according to the low adhesion for electroplating Ni on Ti seed layer, Ni electrode is imprinted on tape to prevent the crack. In this study, the presented process can improve the defect of fabricating polymer device. Finally, it is successful to fabricate the capacitive sensor which has three polymer layers and two metal layers. 36 × 36 capacitive sensor arrays are made in 3.3×3.3 cm2 and space resolution is 650 µm.