奈米碳螺旋線圈應用於皮膚壓力感測器

Fabrication of Carbon Nanocoils Based Tactile Pressure Sensor

李振宏(Cheng-Hung Li)

指導教授 ： 張所鋐

國立臺灣大學/工學院/機械工程學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.02169

摘要

奈米碳螺旋線圈為近年來非常熱門的奈米材料之一，其具有十分有趣的三維奈米螺旋狀結構，是少有的三維奈米材料之一，但現今的奈米碳螺旋線圈備製技術尚未十分成熟，只可成長出數量非常多且十分雜亂的奈米碳螺旋線圈叢，因而限制其應用。而於本論文中提出一種簡單的製程以製做皮膚壓力感測器，利用鐵與錫二元素組成的催化劑成長出奈米碳螺旋線圈叢所組成的薄膜結構，並利用聚二甲基矽氧烷以三明治的包覆方式將所成長出的奈米碳螺旋線圈叢所組成的薄膜結構包覆於其中，成功的製做出可撓性皮膚壓力感測器，而利用奈米碳螺旋線圈所製成的皮膚壓力感測器的靈敏度最高可達0.99 %/KPa，但利用鐵錫二元素所組成的催化劑成長奈米碳螺旋線圈時，會有比例不一的碳纖維產出，而碳纖維的產出比例與催化劑的鐵錫比例有關，因此於本論文中亦挑選幾種不同鐵錫比例的催化劑以成長出不同奈米碳螺旋線圈與碳纖維比例的薄膜結構，並成功的證明，本論文所設計的皮膚壓力感測器的靈敏度會隨奈米碳螺旋線圈叢中所包含的碳纖維比例增加而降低，直至碳纖維比例增加至100 %時，皮膚壓力感測器的靈敏度更降低至0.12 %/KPa。
　　於本論文中亦將所製成的皮膚壓力感測器施以預壓動作，以1500gw(210KPa)的壓力壓於皮膚壓力感測器上24小時，希望可提高其靈敏度與穩定性，但於實驗中發現，所對皮膚壓力感測器施以預壓動作，則會破壞奈米碳螺旋線圈叢的微觀結構，因而不但沒有提高靈敏度，反而降低其靈敏度，因此預壓的動作對本論文所設計的皮膚壓力感測器並無提高靈敏度以及穩定性的效果。

關鍵字

奈米碳螺旋線圈 ； 碳纖維 ； 皮膚壓力感測器 ； 靈敏度 ； 預壓

並列摘要

Carbon nanocoils have attracted a lot of attention due to their unique 3D helical spiral structure. However, presently the synthesis methods of carbon nanocoils have not been well established, resulting in limiting their applications. In this thesis, we demonstrate a promising carbon nanocoil application using carbon nanocoils as core elements to fabricate tactile pressure sensors with high sensitivity. The carbon nanocoil mats first were grown by Fe-Sn catalyst. Subsequently, we utilized the carbon nanocoil mats as a thin film structure and then used the PDMS ( polydimethyl siloxane ) to cover the top and bottom sides to form a sandwich structure. The performance of the fabricated carbon nanocoil tactile pressure sensors was examined by a load cell system. The sensitivity of the tactile pressure can achieve 0.99 %/KPa. Instead of pure carbon nanocoil thin films as sensing core elements, we also investigated the effect of the composition ratio of carbon nanocoils and carbon fibers on the performance of the tactile pressure sensors. It is found that the ratio of carbon fiber and carbon nanocoils in the device dramatically affected the sensing properties.
　　In this thesis, the tactile pressure sensors were also preloaded by 1500 gw (210 KPa) for 24 hrs to observe whether the sensitivity and stability were enhanced. However, our results show that the preloading process would not be able to increase the sensitivity. The reason could be from the damage of the carbon nanocoil mat structure during the preloading process.

並列關鍵字

carbon nanocoil ； carbon fiber ； tactile pressure sensor ； sensitivity ； preloading

參考文獻

[1] W.R. Davis, R.J. Slawson, G.R. Rigby,“ An unusual form of carbon,” Nature 171 (1953) 756.

[2] R.T.K. Baker, M.A. Barbber, P.S. Harris, F.S. Feates, R.J. Waite, “Nucleation and growth of carbon deposits from the nickel catalyzed decomposition of acetylene, ”J. Catal. 26 (1972) 51.

[3] H.P. Boehm,“ Carbon from carbon monoxide disproportionation on nickel and iron catalysts: morphological studies and possible growth mechanisms,”Carbon 11 (1973) 583.

[4] S. Motojima, M. Kawaguchi, K. Nozaki, H. Iwanaga ,“ Growth of regularly coiled carbon filaments by Ni catalyzed pyrolysis of acetylene, and their morphology and extension characteristics, ”Appl. Phys. Lett. 56 (1990) 321.

[5] S. Motojima, Q Chen,“ Three-dimensional growth mechanism of cosmo-mimetic carbon microcoils obtained by chemical vapor deposition,” J. Appl. Phys. 85 (1999) 3919.