具有溯源性的原子力显微镜探针法向弹性常数标定系统  

Traceable Calibration System for the Normal Spring Constant of Atomic Force Microscope Probe

作　　者：宋云鹏[1] 吴森[1] 耿新宇[1] 傅星[1] 

机构地区：[1]精密测试技术及仪器国家重点实验室(天津大学),天津300072

出　　处：《纳米技术与精密工程》2014年第4期249-257,共9页Nanotechnology and Precision Engineering

基　　金：国家自然科学基金资助项目(61204117)

摘　　要：原子力显微镜(AFM)悬臂梁探针的弹性常数在微纳米尺度力学测试中十分重要,其准确程度直接影响力学测量结果的可靠性,故需对其进行精确标定.因天平法的测量结果可溯源,本文在已有天平法的基础上,研制了一套新型标定系统.该系统将AFM测头与超精密电磁天平相结合.微悬臂梁在精密位移台的带动下接触天平并产生弯曲,接触力由天平测得,微悬臂梁的弯曲量由光杠杆检测,并通过反馈系统进行精确控制,最后根据胡克定律计算出弹性常数.利用本系统对4种不同型号商用微悬臂梁探针的法向弹性常数进行了标定,标定结果表明本系统具有良好的测量重复性.通过进行不确定度分析,得到测量结果的相对标准不确定度优于2%.The spring constant of atomic force microscope （AFM） cantilever probe is of great significancein measurement of mechanical properties at micro- and nano-scale, which influences the reliability of mechanical measurement directly. Therefore, the spring constant must be precisely calibrated. Since thetraceability of balance method, a new calibration setup based on the balance method is presented whichcombines ultra-precise electromagnetic balance with AFM test head. When the micro cantilever is approaching the balance by the precision stage, the deflection of the micro cantilever is under servo controland is detected by optical lever. Meanwhile, the contact force is directly measured by the balance. Finally, the spring constant of the micro cantilever is calculated using the Hooke＇s Law. Calibration results ofnormal spring constants of four types of commercial cantilever probes by the system proposed show that thesystem has good measurement repeatability. According to strict uncertainty analysis, the relative standarduncertainty of the calibration results obtained by the proposed system is less than 2%.

关 键 词：悬臂梁 原子力显微镜 法向弹性常数 标定 

分 类 号：TH742[机械工程—光学工程]