垂直陣列奈米碳管/PDMS複合材料在應變感測之應用研究

The use of vertical aligned carbon nanotubes/PDMS composites as strain sensors

李緯節(Wei-Chie Lee)

指導教授 ： 徐文光

國立清華大學/工學院/材料科學工程學系/碩士(2014年)

https://doi.org/10.6843/NTHU.2014.00348

摘要

奈碳管目前應用上最大的阻礙是無法控制大量製備下每根碳管的均一性，故很難做為精密電子電路元件之應用，但是奈米碳管本身所具備的優異機械、導電、導熱性仍不可被否認，因此近年來大家漸漸將目光放在奈米碳管與高分子之複合材料應用上，希望碳管良好的性質能夠使複合材料的巨觀性質得到改善，甚至產生新的功能，而其中應變感測（strain sensor）正是大家關注的應用之一。目前應變感測相關文獻主要是以粉末狀碳管（random）做為應用，此方法最大的問題是不能確保碳管在高分子中分散是否均勻，而本實驗利用熱裂解法製備垂直陣列奈米碳管（vertical aligned CNTs），將其與聚二甲基矽氧烷（PDMS）結合成複合材料（CNTs/PDMS）並製作成應變感測器（電阻式），感測不同受力條件的感測結果。在結構上，本實驗所製備的CNTs/PDMS內部緻密均勻，且碳管在複合材中仍保有方向性；在應變感測上，CNTs/PDMS在不同的受力方向具有穩定且可重複的電阻變化，用SEM觀察壓縮中的CNTs/PDMS結構，發現在平行受力方向有大量裂縫（crack）產生，這些crack垂直於壓縮產生的皺摺（buckling），使得CNTs能在crack中產生新的連接，這樣的現象使得CNTs/PDMS具有獨特的感測結果。

關鍵字

奈米碳管 ； 應變感測

並列摘要

Carbon nanotubes (CNTs)-polymer composites have drawn much attention because of their outstanding electrical, mechanical properties. These make them an attractive candidate as pressure, vibration and tactile sensors. Studies currently focus on composites loaded with dispersed tubes and equivalent circuit consists of tube resistors connected in series and parallel (Rtotal = Rn + 1/Rn). In this case, sensing is isotropic and resistance change is independent of stressing direction. Vertical aligned CNTs exhibit a collective buckling upon compression and return to their original length in a fully elastic way, similar to a spring. In addition vertical aligned CNTs can be grown in array textures and also form composites with polymer. In this work, vertically aligned CNTs are made by pyrolysis and combine with PDMS to form composites with anisotropic sensing character. As shown by experiments, CNTs remain aligned in polymer and Rn governed sensitivity is observed.

並列關鍵字

carbon nanotube ； strain sensor

參考文獻

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