I^2形原子力显微镜探针设计优化

Design optimization of I^2 shaped AFM probe

针对基于微机电系统(MEMS)技术的I^2形原子力显微镜(AFM)探针与传统悬臂式探针相比,虽然有很多优点,但由于I^2形探针的压阻检测设计未考虑结构应变分布,导致检测灵敏度较悬臂式探针相比尚有一定差距的问题,通过对I^2形探针应变分布的考察,实现了探针结构优化设计。实验结果表明:在相同结构,相同输入前提下,改进后探针的力灵敏度达到28. 9p N/Hz^(1/2),较原有基础上提高10倍。通过进一步对检测电路的优化,力灵敏度有望满足商用需求(小于10p N/Hz^(1/2))。

Aiming at the problem that comparing with conventional cantilever probe,although MEMS-based I^2 shaped atomic force microscope(AFM)probe has many advantages,piezo-resistive detection design does not consider strain distribution of structure,which results in detection sensitivity has a gap,compared with cantilever probe,by investigating of strain distribution of I^2 shaped probe,realize optimization design of probe structure.Experimental results show that in the premise of same structure and same input,force sensitivity of probe after improvement reach 28.9 pN/√Hz1/2,which improved 10 times.By further improvement,force sensitivity hopefully meet the commercial requirement(<10 pN/√Hz1/2).