提升超小型微懸臂感應系統靈敏度之研究

Study of Improving Sensitivity of an Ultra-Small Cantilever Detection System

吳艾庭(Ai-Ting Wu)

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(2021年)

https://doi.org/10.6342/NTU202102256

摘要

原子力顯微鏡擁有高解析度以及不受真空環境限制的優點，使其在生醫領域有廣泛的應用。為了即時觀測快速之生物動態反應，高速原子力顯微鏡的開發因應而生。為提升掃描速度，高速原子力顯微鏡需要使用更加微小的超小型微懸臂探針來進行量測。然而，量測超小型微懸臂需搭配具聚焦光點更小之客製化微懸臂光學感測系統。本論文開發一可量測超小型微懸臂之感測系統，此小型光路模組之尺寸為40 × 23 × 24 mm3，可方便更換光學元件以及雷射光源，並可在實驗時同時觀察內部光路。為了提升此微懸臂量測系統之靈敏度，本論文測試紅光雷射CPS635R、LDM115G、NovaPro、藍光雷射LuxX plusoR 405-120、雷射二極體L637P5等不同種類之雷射光源。其中紅光雷射LDM115G可得到最佳之靈敏度0.45 mV/nm，雜訊峰對峰為 4 mV，雜訊峰對峰值對應之位移量為 8.83 nm。感測系統之最小的光點尺寸可達4.5 μm，符合量測寬度5 μm超小型微懸臂之要求。

關鍵字

超小型微懸臂 ； 光偏折 ； 刀緣法 ； 靈敏度

並列摘要

Atomic force microscopes (AFMs) can achieve high resolution in ambient, liquid, and vacuum environments, which have been widely applied in the biomedical field. To monitor the dynamic behavior of bio-samples, high-speed AFMs were realized through applying ultra-small cantilevers for increasing the scan speed. However, a customized cantilever detection system with a small laser spot was required to measure the ultra-small cantilever. In this thesis, a modular cantilever detection system with a small size of 40 × 23 × 24 mm3 was proposed. The optical components and the laser in this system can be replaced conveniently, and the internal optical path can be monitored during the experiment. To optimize the sensitivity of the cantilever detection system, various lasers including red lasers (CPS635R, LDM115G, NovaPro), a blue laser (LuxX plusoR 405-120), and a laser diode (L637P5) were tested. The experimental results show that the red laser LDM115G had the highest sensitivity of 0.45 mV/nm, while the peak-to-peak noise was 4 mV which correspnded to 8.83 nm. The smallest laser spot size of the proposed system was 4.46 μm, which can fit the ultra-small cantilevers with a width of 5 μm.

並列關鍵字

Ultra-small cantilever ； Beam-deflection ； Knife-edge method ； Sensitivity

參考文獻

[1] S. Vahabi, B. Nazemi Salman, and A. Javanmard, "Atomic force microscopy application in biological research: a review study," Iranian journal of medical sciences, vol. 38, no. 2, pp. 76-83, 2013.

[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] H.-J. Butt, B. Cappella, and M. Kappl, "Force measurements with the atomic force microscope: Technique, interpretation and applications," Surface science reports, vol. 59, no. 1, pp. 1-152, 2005.

[4] 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.

[5] A. Lewis, M. Isaacson, A. Harootunian, and A. Muray, "Development of a 500 Å spatial resolution light microscope: I. light is efficiently transmitted through λ/16 diameter apertures," Ultramicroscopy, vol. 13, no. 3, pp. 227-231, 1984.