Lubricating a bright future: Lubrication contribution to energy saving and low carbon emission

Both the academic society and the industry are hunting for new energy forms for the future. However, the world should not forget the conventional technologies that contribute to the sustainable society by technical innovations. Among them, lubrication plays a significant role in energy saving and in low CO₂ emission by increasing the fuel efficiency and by prolonging the service life of machines. With the advance of novel synthetic approaches, and nanoscience and technologies, novel lubrication oils and additives and their formulations are being developed to reduce friction and wear, and novel surface treatment routes and surface coatings are invented and provide more efficient lubrication. These technologies create tremendous chances for machines to work more efficiently with low energy consumption. Here we review the recent progresses and challenges associated with some novel lubrication techniques that include novel surface treatment (such as texturing, high-performance nanocomposite coatings, adapting coating), tribology design (solid and liquid lubrication), energy-conserving engine oil and novel lubricants and formula (such as ionic liquids, low S, P content additives) which are to be adopted to enhance the fuel efficiency to achieve energy saving and low carbon emission. There is increased demand to replace fossil lubricants by degradable green lubricants. Specially designed coatings can reduce drag significantly during navigation of both airplanes and ships. All these aspects will be also reviewed in the paper.