基於氦氖雷射之超小型微懸臂感測系統之設計與開發

Design and Development of an Ultra-Small Cantilever Detection System based on a He-Ne Laser

陳式新(Shih-Shin Chen)

指導教授 ： 廖先順

國立臺灣大學/工學院/機械工程學研究所/碩士(2022年)

https://doi.org/10.6342/NTU202201354

摘要

原子力顯微鏡具有奈米等級解析度，並可在液體中進行量測，因此被廣泛應用於生醫量測領域。一般原子力顯微鏡由於掃描速度較慢，所以無法觀測許多快速之動態現象。高速原子力顯微鏡係利用超小型微懸臂探針提升掃描速度。然而，超小型微懸臂需要利用具更小雷射光點之特殊光學感測系統來量測其偏折量。本論文設計開發一模組化之超小型微懸臂感測系統，此系統具有體積小(31 × 43 × 26 mm3)、小光點直徑(3.6 μm)、且可方便更換其光學元件和雷射光源等優點。系統採用穩定的紅光氦氖雷射光源以降低雜訊，並測試了不同的光學元件之組合以提升量測靈敏度。結果顯示採用立體式分光鏡PBS052、聚焦透鏡A240-A、位置感測器SPOT-9DMI和超小型微懸臂探針USC-F2-k3之組合能得到最佳之靈敏度0.4 nm/mV。系統雜訊峰對峰值為3.6 mV，對應之位移量為1.44 nm。實驗使用此組合對標準樣品TGQ1進行高速掃描成像，掃描速度可達100 line/s，且不影響影像品質。

關鍵字

超小型微懸臂 ； 光偏折 ； 靈敏度 ； 高速原子力顯微鏡

並列摘要

Atomic force microscope (AFM) equips nanoscale resolution and can be operated in liquid environment, which has been widely used in biomedical measurement. Due to the slow scanning speed, common AFMs are not able to monitor dynamic phenomena. The high-speed AFM (HS-AFM) can improve the scanning speed significantly by using an ultra-small cantilever. However, a customized cantilever detection system with a small laser spot is required to detect the deflection of the ultra-small cantilever. In this thesis, we developed a modular ultra-small cantilever detection system, which had the advantages of compact size (31 × 43 × 26 mm3), small laser spot diameter (3.6 μm), and feasibility to replace the optical components and laser light source. To improve the sensitivity of the cantilever detection system, a stable He-Ne laser was adopted, and different combinations of optical components were tested. The experimental results show that the combination of the beamsplitter cube PBS052, the focusing lens A240-A, the position sensitive detector SPOT-9DMI and the ultra-small cantilever probe USC-F2-k3 provided a highest sensitivity of 0.4 nm/mV. The peak-to-peak noise of the system was 3.6 mV, which corresponded to 1.44 nm in displacement. The experiment demonstrated that a grating sample TGQ1 can be stably imaged at a high scan rate of 100 line/s.

並列關鍵字

Ultra-small cantilever ； Beam-deflection ； Sensitivity ； HS-AFM

參考文獻

[1]S. Liu, Y. Wang, "Application of AFM in microbiology: a review," Scanning, vol. 32, issue. 2, pp.61-73, 2010.

[2]G. Binnig, H. Rohrer, C. Gerber, and E. Weibel, "Surface Studies by Scanning Tunneling Microscopy," Physical review letters, vol. 49, no. 1, pp. 57-61, 1982.

[3]黃英碩, "掃描探針顯微術的原理及應用," 科儀新知, vol. 144, 2005.

[4]G. Binnig, C. F. Quate, and C. Gerber, "Atomic force microscope," Physical review letters, vol. 56, no. 9, pp. 930-933, 1986.

[5]T. Ando, T. Uchihashi, and N. Kodera, "High-speed AFM and applications to biomolecular systems," Annual review of biophysics, vol. 42, pp. 393-414, 2013.