原子力显微镜微悬臂梁品质因数的数字调控技术的研究.pdf

) ) ) 房 轩 李艳宁 胡晓东 胡小唐 天津大学精密测试技术及仪器国家重点实验室, 天津, 300072 : 为 提高轻敲模式原子力显微镜的微悬臂梁的低品质因数, 在分析品质因数调控技术原理的 基础上, 设计 基于D SP 的品质因数数字调控系统该系统结构简单, 操作方便, 智能性和实时性好, 能够比较精确地调控微悬臂梁振动的品质因数通过对比液体中微悬臂梁振动的频谱以及蛋白质分子 的成像实验证明, 该数字调控电路能够提高微悬臂梁的力灵敏度, 非常适合用于对软样品的检测 : ; ; ; : T N 16 : 1004 ) 132X( 2007) 13 ) 158 1) 0 3 Digital Adjustment of AFM Microcantilevers. Quality Factor F ang X uan L i Y anning H u Xiaodong H u X iao ang S a e Key L abora ory of P recision M easur ing T echnolo gy and Ins rumen s, T ianjin Univ er si y, T ianjin , 300072 Abstract: T he low quali y fac o r ( Q - f ac or ) of micr ocan ilever w hen oper a ing an a omic fo rce micro scopy in apping m ode in liquid limi s he ins rumen . s reso lu ion and sensi ivi y. By analy zing he Q - f ac or con rol heo ry, a mo dule based o n a DSP ( dig i al sig nal processor) echnique w as devel- o ped o digi al ly une he Q - fac o r of a m icrocan ilev er . T he m odule has he advan ages of sim ple s ruc ure, easy opera ion , fas f eedback con rol and high Q - f ac or uning precision . By comparing he f requency spec ra of a microcan ilev er in liquid and pro ein molecule. s images in bu anol so lu ion respec ively, i is sho wn ha he digi al Q - f ac or uning module can improve for ce sensi ivi y of he micro can ilever and is sui able fo r es ing sof sam ples. Key words: a omic f orce micro scopy ; m icrocan ilever; quali y fac or ; apping m ode [ 4O8] 0 引言 ( a o mic f orce m icrosco py, DSP , A FM ) , , [ 1O3] A F M ( con ac mo de) , , , ( apping mode)