以PDMS微結構的電容式壓力感測器

Abstract

在本篇論文中，我們利用具有非等向蝕刻特性的氫氧化鉀，蝕刻已經被光蝕刻過的矽晶圓來製作具有金字塔結構的模具。我們使用翻模的技術來使二甲基矽氧烷表面具有金字塔的結構。具有微結構的二甲基矽氧烷壓再鍍有氧化銦錫薄膜的可饒的聚酯薄膜基板上再與另一片鍍有氧化銦錫薄膜的聚酯薄膜基板壓在一起形成可撓的電容式壓力感測器。具有微結構的二甲基矽氧烷被當作是電容的介電層。當我們對具有微結構之聚二甲基矽氧烷施加壓力造成型變、膜厚改變導致有效介電系數變化，進而改變了聚二甲基矽氧烷的電容值。因此我們可藉由測量電容值變化，進而得知目標壓力大小。利用微結構來降低聚二甲基矽氧烷的黏彈性與彈性阻力，進而達到高敏感度。這對開發電容式的壓力感測器是一個新的方向。

In this thesis, we use the anisotropic KOH to etch on the photolithography patterned silicon wafer in order to fabricate pyramid structures. We utilize the technology of the moulding replication to create the pyramid structures on the surface of PDMS. Structured PDMS film was laminated onto the ITO-coated PET film then laminated with another ITO-coated PET film to form flexible capacitive pressure sensor. The structured PDMS was used as the dielectric layer of the capacitor. It is found that the thickness and effective permittivity of the structured PDMS dielectric layer can be changed when the pressure was loaded on the device. This behavior induced a change in capacitance of the compressible structured PDMS. We can know the pressure values of the target items by measuring the capacitance changes. The reduction of the elastic resistance and viscoelastic were attributed to the structured PDMS, thus achieving the high sensitivity. It is believed that this study will pave a new way for the development of pressure sensors.