Research On The Measurement Technology Of Micro Scale Mechanical Properties Based On Micro Cantilever Bending Method

With the development of micro-nano technology,low dimensional microstructures based on new materials with small size and high performance have become one of attractive topic in recent scientific research field,such materials include Nanoscale Thin Film?Carbon Nanotube?Nanowire?Graphene?Black phosphorus and so on.Micro electro mechanical system(MEMS)devices achieve a great development and wide application field with the improvement of new micromachining process.However,as the small sizes of micro scale materials and devices,the influence of scale effect is very big.The mechanical properties of micro scale structures are different from that of normal size materials and structures.The mechanical properties of micro-nano scale materials directly affect the performance of the designed micro devices.So the research and measurement of the mechanical properties is one of the main issues to the design and evaluation of micro structures,and needed to be solved urgently.In this article,we analyze the shortage of the existing methods,design and build a homemade micro scale mechanical property detecting system based on micro cantilever probe bending measurement principle.In this system,the spring constant of the micro cantilevers can be calibrated in situ.With the high precision microscopic interferometry surface topography measurement module added in the system,the measurement accuracy and the application field of the system are improved.The main work of this paper includes:(1)The measurement principle and method of mcro scale mechanical property are analysed in detail.A micro scale mechanical property detecting method based on micro cantilever probe bending method is built.The performance of the system is detected carefully to meet the measurement requirement of micro scale mechanical properties.(2)The normal spring constant calibration methods are discussed.We calibrated the normal spring constant of many kinds of cantilevers in situ,and evaluated the uncertainty of the calibration results.Comparisons of calibration results in different methods are carried out to evaluate the merit shortcomings and application fields of each method.(3)Three kinds of special cantilevers with ultra-small size ultra-high stiffness or tipless are calibrated with our method.These cantilevers are hardly calibrated with other methods or only can be calibrated with relatively large uncertainty.The calibration results indicate that the characteristic parameters of cantilevers such as shape dimension and stiffness are not needed to be considered in our method.We can calibrate almost all kinds of cantilevers used in AFM field.(4)A new method which can calibrate the lateral spring constant of micro cantilever probes is achieved with our system.Then we analysis and evaluate the calibration results carefully.After that,one cantilever probe which has calibrated the lateral spring constant is used to test the lateral force in accurate force measurement application.The measurement accuracy and reliability of the lteral force is improved.(5)Micro force load based on micro cantilever bending method and surface topography characterized with microscopic interferometry method are used to study the mechanical properties of bubbly structure which appeared in Cu Film on PMMA substrate after uniaxial compression load.Then the interfacial adhesion energy of the film/substrate structure is studied in a new method with our system.