Bibliometric analysis of micro-nano manufacturing technologies

Manufacturing is the primary industry promoting economic and social development.For the past 30 years,the global trends of preciseness and device miniaturisation have promoted manufacturing to the micro(μ)and nano(η)scale.Identification of themost promising micro-nano manufacturing technologies(MNMT)is of interest to industry,academia and private and national science investing foundations.Considering the exponential broadening of the research area and an enormous volume of literature,providing an overview of the state of the art is far beyond the scope of a technical review paper.This study performs bibliometric analysis of a stream of academic literature devoted toμ-andη-machining.Themain goals of the analysis are to assess the current core and trends in the field ofMNMT.Literature and citation statistics from 1988 were collected from theWeb of Science,Google Scholar,Scopus,Engineering Village,ScienceDirect and SpringerLink databases and were then analysed and illustrated with Microsoft Excel and VOSviewer software.The top keywords,articles,journals,authors,universities and countrieswere identified according to different parameters.The index of normalised influence was offered to evaluate the top element in each category.We observed that the most powerful keywords were present in well-known articles published in prominent journals by authoritative scientists at leading universities in the countries that are most actively engaged in MNMT.The implications of the research outcomes for investors and academicians are summarised in the conclusion.

Tribological study on the surface modification of metal-on-polymer bioimplants

The tribological performance of artificial joints is regarded as the main factor of the lifespan of implanted prostheses. The relationship between surface roughness and coefficient of friction (COF) under dry and lubricated conditions is studied. Results show that under dry test, friction coefficient is not reduced all the time with a decrease in surface roughness. On the contrary, a threshold of roughness value is observed, and frictional force increases again below this value. This critical value lies between 40 and 100 nm in Sa (roughness). This phenomenon is due to the transfer of friction mechanisms from abrasion to adhesion. Under wet test, COF always decreases with reduction in surface roughness. This result is mainly attributed to the existence of a thin layer of lubricant film that prevents the intimate contact of two articulating surfaces, thus greatly alleviating adhesion friction. Furthermore, surface texturing technology is successful in improving the corresponding tribological performance by decreasing friction force and mitigating surface deterioration. The even-distribution mode of texturing patterns is most suitable for artificial joints. By obtaining the optimal surface roughness and applying texturing technology, the tribological performance of polymer-based bioimplants can be greatly enhanced.