BAI Jiang-hua, Andres La Rosa
（Department of Physics, Portland State University, Oregon 97201, USA）
Abstract： A fully automated atomic force microscope (AFM) is presented. The mechanical motion of the AFM stage was controlled by three steppers. The fine motion of the AFM was controlled by an MCL one-axis piezo plate. A 32.768 kHz crystal tuning fork (TF) was used as the transducer with a probe attached. An acoustic sensor was used to measure the interactions between the probe and the sample. An SR850 lock-in amplifier was used to monitor the TF signals. An additional lock-in amplifier was used to monitor the acoustic signal. A field programmable gate array (FPGA) board was used to collect the data in automatic mode. The main controller was coded with LabVIEW, which was in charge of Z-axis scan, signal processing and data visualization. A manual mode and an automatic mode were implemented in the controller. Users can switch the two modes at any time during the operation. This AFM system showed several advantages during the test operations. It is simple, flexible and easy to use.
Key words： atomic force microscope (AFM); nano indentation; acoustic sensing; piezo drive; crystal tuning fork; LabVIEW; lock-in amplifier; 8051 microcontroller
CLD number： TH742 Document code： A
Article ID： 1674-8042（2018）04-0347-07 doi： 10.3969/j.issn.1674-8042.2018.04.007
References
［1］ Bai J H , Freeouf J, Rosa A L. Implementing an SPM controller with LabVIEW. Journal of Measurement Science and Instrumentation, 2018, 9(3): 257-268.
［2］ Bai J H , Rosa A L. An SPM stage driven by 3 stepper motors. Journal of Measurement Science and Instrumentation, 2017, 8(3): 271-276.
［3］ Nony L, Bocquet F, Para F, et al. Frequency shift, damping, and tunneling current coupling with quartz tuning forks in noncontact atomic force microscopy. Physical Review B, 2016, 94(11/12/13/14/15): 115421-16.
［4］ Stanford Research Systems. SR850 DSP lock-in amplifier operating manual and programing reference, 2009.
［5］ Ametek Advanced Measurement Technology Inc. Model 7265 DSP lock-in amplifier instruction manual, 2002.
［6］ National Instruments. Getting started with LabVIEW FPGA. ［2018-03-18］. http:∥www.ni.com/tutorial/14532/en/.
［7］ Park Systems Corporation. Chapter 4, Scan mode, XEP software manual, 2013.
［8］ Park Systems Corporation. Chapter 9, Dynamic force microscopy, XE-120 user’s manual, 2013.
［9］ Bai J H , Rosa A L. Essentials of building virtual instruments with LabVIEW and Arduino for lab automation applications. International Journal of Science and Research, 2017, 6(5): 640-644.
［10］ Bai J H, Chen J W, Freeouf J, et al. A 4-layer method of developing integrated sensor systems with LabVIEW. Journal of Measurement Science and Instrumentation, 2013, 4(4): 307-312.
［11］ Mad City Labs Inc. Nano-drive 85 user manual, 2007.
一个用于纳米压痕和应力测试的全自动原子力显微镜系统
白江华, Andres La Rosa
（波特兰州立大学 物理系， 俄勒冈州 97201）
摘 要: 本文设计了一台专门用于纳米压痕和应力测试的原子力显微镜。 显微镜的基座由三个步进电机控制， 显微镜的精确运动由MCL 压电陶瓷控制。 显微镜的主动传感器由水晶音叉与粘在音叉上的探针组成， 探针与待测样品之间的应力作用由一个精密超声波传感器来测量， 传感器的信号由两台锁相放大器来处理。 最终， 所有数据由FPGA 卡集成接收并传给电脑控制器。 显微镜的主控制器用LabVIEW编写， 主要负责Z方向扫描、 信号处理以及数据的图形化显示。 控制器中植入了手动和自动两种模式， 用来控制显微镜的运动和进行信号处理， 在运行过程中用户可以在两种模式之间切换。 调试与试运行结果显示， 该原子力显微镜有简单灵活、 使用方便等诸多优点。
关键词: 原子力显微镜； 纳米压痕； 超声检测； 压电陶瓷驱动； 水晶音叉； LabVIEW； 锁相放大器； 8051单片机
引用格式： BAI Jiang-hua, Andres La Rosa. An automated AFM for nanoindentation and force related measurements. Journal of Measurement Science and Instrumentation, 2018, 9(4)： 347-353. ［doi： 10.3969／j.issn.1674-8042.2018.04.007］
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