Surface- and Tip-Enhanced Raman Scattering in Tribology and Lubricant Detection-A Prospective

Surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS) are fast, convenient, and non-destructive molecular detection techniques, which provide a practical method for studying interfacial reactions with high resolution and accuracy. Both techniques are able to provide quantitative and qualitative information on the chemical properties, conformational changes, order state, and molecular orientation of various surfaces. This paper aims at summarizing the research efforts in the field of SERS and TERS related to tribological systems with a special emphasis on thin film and nanoparticles. This overview starts with a brief introduction for both techniques. Afterwards, it summarizes pros and cons of both techniques related to the advanced characterization of tribologically induced reactions layers. Moreover, the feasibility of both techniques to evaluate the friction and wear performance of new lubricant additives including solid lubricants is discussed. At the end of this review article, the main challenges and future directions in this field are prospected to emphasize the development direction of SERS and TERS in tribology and lubricants.