基于弯曲法的AFM微悬臂梁弹性常数标定技术  

Calibration of the spring constant of AFM micro-cantilever based on bending method

作　　者：吴森[1] 陈庆超[1] 张超[1] 傅星[1] 胡晓东[1] 胡小唐[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《仪器仪表学报》2012年第11期2446-2453,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(61072013;51075297)资助

摘　　要：原子力显微镜(atomic force microscopy,AFM)在微纳米尺度力学测量领域有着广泛应用,其微悬臂梁探针的弹性常数是直接影响测量结果准确性的关键因素之一。弯曲法是标定微悬臂梁弹性常数的一类重要方法,基于弯曲标定原理提出了一种新的技术实现方案,并研制了相应的标定系统。借助精密运动定位台使微悬臂梁接触超精密天平并产生弯曲,分别以天平和光杠杆机构同步测得接触力和梁的弯曲量,再根据胡克定律直接算得弹性常数。利用所研制的系统对多种型号的微悬臂梁进行了标定,实验结果表明该系统具有良好的准确性和重复性,测量相对标准差小于5%。Atomic force microscopy （AFM） is widely spring constant of the AFM micro-cantilever probe is used in force measurement field at micro/nanometer-scale. The one of the key factors that influence the accuracy of the measurement result. Bending method is a popular way tO determine the spring constant of micro-cantilever. A new technical implementation scheme is proposed and corresponding calibration system is developed based on the bending calibration principle in this paper. In this scheme a precise positioning stage is used to make the micro-cantilever contact with the ultra precision electromagnetic compensated balance, and the micro-cantilever generates bending. The ultra precision electromagnetic compensated balance and optical lever are used to synchronously measure the contact force and the deflection of the micro-cantilever respectively. The spring constant is then simply obtained according to the Hooke＇s law. Multiple types of micro-cantilevers were calibrated with this system. Experiment results indicate that the system possesses good accuracy and repeatability; and the relative standard deviations are less than 5%.

关 键 词：原子力显微镜 悬臂梁 弹性常数 标定 天平 光杠杆 

分 类 号：TH73[机械工程—仪器科学与技术]