多孔性壓阻式感測器的孔隙結構和靈敏度之研究

Studies on the Porous Structure and Sensitivity of Pressure Sensor

蕭富仁(Fu-Ren Xiao)

指導教授 ： 廖英志

國立臺灣大學/工學院/化學工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201802001

摘要

本論文主要在探討多孔性結構在不同發泡條件下，氟橡膠(DAI-EL™-G801)、單壁奈米碳管(SWCNT)和不同發泡劑比例(AIBN和DPT)的導電橡膠的發泡結構對於電阻係數與機械性質變化的影響。壓阻式壓力感測器是直接將機械應變轉換為電阻變化，由於其簡單的讀出機制、簡易的製程和高像素密度而被廣泛使用。傳統壓阻式橡膠由於本身的黏彈性，導致楊氏係數過高，造成了許多問題，如蠕變現象、緩慢響應時間和壓力感測的靈敏度極低等等。在0-200kPa的壓力範圍內，我們透過多孔性結構降低了八倍壓阻橡膠的楊氏模量，因此在相同的壓縮應力下產生更多的應變，壓力感測的靈敏度相對增加了約12.8倍。
接著我們改變發泡劑的含量來控制孔徑大小(1.8-0.43mm)，得以調控壓阻式壓力之靈敏度(2.63-4.31 MPa-1)。然而不同壓縮速率會產生有不同的延遲時間，當壓縮速度提升時(5 - 25mm/min)，其相對電阻和應力越容易穩定，反應/回復時間也從7秒減少至2秒。為了探討多孔橡膠的耐久性，我們以同等應力(200kPa)和速率(25mm/min)去重覆壓縮多孔性橡膠一千次，其相對電阻無明顯變化。本實驗通過印刷技術、簡易的混摻和熱處理來簡化製作過程，且能微小化和設計陣列感應電極的尺寸（0.125 mm2）和圖案，應用在打擊壓力感測器來偵測出拳的壓力(50-120kPa)、出拳週期(3.5-1 sec/punch )和出拳的次數等等。

關鍵字

多孔性結構 ； 壓阻式壓力感測器 ； 靈敏度

並列摘要

The purpose of this study was to investigate the effect of porous structure on the sensitivity of pressure sensing and Yong’s modulus. The piezoresistive rubber was composed of fluorine rubber (DAI-ELTM-G801), single wall carbon nanotube (SWCNT) and different foaming agent (AIBN and DPT). The piezoresistive sensor transferred mechanical strain into varying resistance and is widely used because of its simple readout mechanism, simple process and potential high pixel density. Due to the viscoelasticity, traditional piezoresistive conductive rubber possess high Yong’s modulus which lead to the creep phenomenon, slow response time and low sensitivity. We used porous structure to decreased Yong’s modulus eight times in the range of 0-200kPa, which can enhance the deformation to create more conductive path under the same stress and the sensitivity of pressure sensing increased about 12.9 times.
To control the pore size (1.8-0.43mm), we changed the foaming agent content to adjust the piezoresistive pressure sensitivity (2.63-4.31 MPa-1). However, different compressive rates can influence delay times. When the compression rate is increased (5-25 mm/min), the relative resistance and relative stress reached stability more quickly, so the reaction/recovery time is reduced from 7 seconds to 2 seconds. By comparing with traditional piezoresistive rubber at the same stress (200kPa) and rate (25mm/min) compressing in 1000 cycle, the relative resistance of porous rubber did not change significantly, showing great durability. This method simplifies the fabrication, miniaturized the size (0.125 mm2) and design conductive pattern of the array sensing electrode through printing technology, simple mixing and heat treatment, which can be applied to the boxing sensor to detect the punching strength (50-120kPa), punching cycle time (3.5-1 sec/punch) and the number of punches.

並列關鍵字

Porous structure ； piezoresistive pressure sensor ； sensitivity

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