基於高靈敏度正溫度係數複合材料之溫度振盪器

Development of Temperature Oscillator Based on High-sensitivity Positive Temperature Coefficient Composite

徐銘辛(Ming-Xin Xu)

指導教授 ： 楊燿州

國立臺灣大學/工學院/機械工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201802310

摘要

本文提出了基於微機電技術製造的溫度振盪器之設計、製造和特性分析。提出的溫度振盪器由微型超靈敏溫度感測器和微型加熱器組成。其中，溫度感測器是透過在指叉電極上沉積具有正溫度係數(PTC)效應的丙烯酸酯共聚物複合材料實現的，並作為產生溫度振盪現象的關鍵部件。丙烯酸酯共聚物複合材料是將石墨顆粒分散在丙烯酸酯共聚物中製備的。丙烯酸酯共聚物複合材料在1.5 ℃的溫度變化下表現出超過四個數量級的電阻率變化。利用複合材料電阻率的變化，週期性地開關微型加熱器，實現溫度振盪現象。
本文在理論分析的基礎上，確定了基於丙烯酸酯共聚物複合材料的溫度振盪器之設計參數。完成了丙烯酸酯共聚物複合材料和溫度振盪器的製程設計。並以微機電技術完成了丙烯酸酯共聚物複合材料的製備以及溫度振盪器系統的製造。研究結果顯示，基於丙烯酸酯共聚物的傳感器在1.5 ℃的溫度變化內表現出超過四個數量級的電阻率變化。測量了元件的暫態行為和系統參數對性能的影響。測量結果表明，在長期試驗中溫度漂移不明顯，這表明丙烯酸酯複合材料在反覆相變過程中具有高可靠性。

關鍵字

致動器 ； 振盪器 ； 溫度感測器 ； 微機電系統 ； 微機械元件

並列摘要

This thesis presents the design, fabrication, and characterization of a temperature oscillator fabricated by MEMS technology. The proposed device consists of a miniaturized ultra-sensitive temperature sensor and a microheater. The temperature sensor was fabricated by depositing acrylate-based temperature sensing material with a positive temperature coefficient (PTC) on an interdigital electrode pair. The PTC material was the key element which enables temperature oscillations by periodically switching the microheater on and off. The acrylate-based composite, which was prepared by dispersing acrylate copolymer with graphite particles, exhibits four order-of-magnitude variation in resistivity over a temperature change of 1.5 ℃.
Based on the theoretical analysis, the design parameters of the proposed oscillator were determined. The preparation of the acrylate copolymer composite and the fabrication of the temperature oscillator were realized by micromachining techniques. The measured results showed that the acrylate-copolymer-based sensor exhibited a resistance variation about four orders of magnitude over a small temperature range of only 1.5 ℃. The transient behavior of devices was measured. In addition, long term measurement of the device over 1000 cycles shows that the temperature drift is not obvious, which indicates that the acrylate composite has high reliability in the repeated phase transformation process.

並列關鍵字

Actuators ； oscillators ； temperature sensors ； microelectromechanical systems ； micromechanical devices

參考文獻

[1] S. D. Senturia, Microsystem design: Kluwer Academic Publishers, 2001.

[2] J. Zha, B. Zhang, R. Li, and Z. Dang, "High-performance strain sensors based on functionalized graphene nanoplates for damage monitoring," Composites Science and Technology, vol. 123, pp. 32-38, 2016.

[3] H. Liu, Y. Li, K. Dai, G. Zheng, C. Liu, C. Shen, X. Yan, J. Guo and Z. Guo, "Electrically conductive thermoplastic elastomer nanocomposites at ultralow graphene loading levels for strain sensor applications," Journal of Materials Chemistry C, vol. 4, no. 1, pp. 157-166, 2016.

[4] X. Wu, Y. Han, X. Zhang, and C. Lu, "Highly Sensitive, Stretchable, and Wash-Durable Strain Sensor Based on Ultrathin Conductive Layer@Polyurethane Yarn for Tiny Motion Monitoring," ACS Applied Materials Interfaces, vol. 8, no. 15, pp. 9936-9945, 2016.

[5] M. Yurddaskal, M. Erol, and E. Celik, "Carbon black and graphite filled conducting nanocomposite films for temperature sensor applications," Journal of Materials Science: Materials in Electronics, vol. 28, no. 13, pp. 9514-9518, 2017.