Development Of Multi-Probe Cooperative Measurement Platform For Friction Energy Dissipation In Superlubricity

According to statistics,approximately one-third of world's primary energy consumption is attributed to friction.Hence,reduction of friction loss and energy consumption is one of global focuses.The discovery of superlubricity state provides a precious opportunity to solve this problem,and attracts great international attentions.The research of superlubricity is still in its preliminary exploration period.The nature and mechanism of superlubricity,which is closely related with the energy dissipation during friction process,is unclear and remains an unsolved mystery at the present.Based on the above requirements,a design method of atomic force microscopy micro-cantilever probe for the ultra-low friction coefficient measurement for superlubricity is proposed in this paper.Based on the measurement principle of atomic force microscopy,this paper establishes an universal theoretical model for measuring friction coefficient through friction force and normal force,which is measured by the torsion and bend of micro-cantilever probe.And then,according to the structural characteristics of micro-cantilever probe with special cross-section,this paper establishes a theoretical model for measuring friction coefficient through micro-cantilever probe with special cross-section.On the basis of the theoretical model,combining with the constraints of the resolution of friction coefficient,the maximum normal force or the friction force,the characteristics of atomic force microscopy and the machinability of the probe,a special-shaped cross-section micro-cantilever probe is calculated and designed,and was verified by finite element simulation.In order to realize the processing of special-shaped cantilever probe,a method of focused ion beam?FIB?etching is proposed to fabricate special-shaped cross-section micro-cantilever probe with designed size.The probe designed by this method can realize the measurement of ultra-low friction coefficient with resolution of 10^-7 or lower.It can significantly improve the resolution of friction coefficient measurement and realize the measurement of ultra-low friction coefficient,thus ensuring the authenticity and reliability of quantitative analysis of superlubricity process,and providing an important technical method for in-depth study of superlubricity theory and technology.On the basis of realizing the detection of ultra-low friction coefficient,this paper further designs a high-precision multi-probe cooperative measurement platform,which can realize the exchange of various functional probes in the same environment,so as to realize various testing methods for the superlubricity surface,and provide an effective technical basis for the study of superlubricity energy dissipation.At the same time,the performance of the device was tested,and the efficient and accurate exchange of different functional probes was realized in the vacuum environment.Then the functions of in-situ surface morphology scanning,micro-friction and wear,and friction coefficient measurement were realized in the same environment in the same experimental area on the sample surface.Based on the above research,the main work and innovative research results of the technical methods applied to the superlubricity energy dissipation detection in this paper are summarized as follows:1.A design method of atomic force microscopy micro-cantilever probe for detecting ultra-low friction coefficient in super-slip state is proposed.A universal theoretical model is established to determine the key factors,which are verified by finite element method.2.According to the above design method,the U-shaped cross-section microcantilever is preferably used to measure the ultra-low friction coefficient,and the processing is completed by focused ion beam,and the U-shaped cross-section microcantilever probe can realize the super-resolution of 10^-7 in the measurement of ultra-low coefficient of friction.3.A multi-probe cooperative detection platform is designed and manufactured.The device can carry eight probes,and can detect the super-slippery surface with multi-functional probes,such as in-situ surface topography scanning,micro-friction and wear detection and friction coefficient detection.