基于快速原子力显微镜的正弦驱动信号设计

Design of Sine Driving Signal Based on Characteristic of High Speed Scan of Atomic Force Microscopy

随着人们对微观世界的探知需求,原子力显微镜(AFM)的扫描速度与扫描范围愈发限制其在纳米级领域的应用。各种提高AFM扫描速度的手段应运而生。通过分析扫描速度过快对图像的影响以及对正弦驱动可行性的考察,利用Filed ProgrammableGate Array(FPGA)为核心,结合基于PC104控制系统的AFM的快速扫描的特点,设计正弦波驱动信号。设计中采用查表的方式以及嵌入式niosⅡ处理器,实现正弦信号的输出与串口通讯。从而将AFM扫描探针的驱动信号由传统的三角波变为正弦波以提高其扫描速度。

In the process of exploring microscopic world, the scan speed and scale of Atomic Force Microscopy （AFM） is limiting its application in the nanometer level filed. Thus, the engineers have worked out a lot of methods of increasing the scan speed of AFM. Through the analysis of image distortion aroused by over speeding scan and the feasibility of sine signal driving, this paper presented the design of sine signal driving the scan tube of AFM using Filed Programmable Gate Array （FPGA） as the core processor, combining with the fast scan characteristic of the PC104-Controled AFM. This design used look-up table method to generate sine signal and embedded Nios processor to achieve serial communication. In order to increase the scan speed of AFM, the driving signal was changed from triangle to sine signal.