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We present a review of superlubricity: the state of ultra-low friction between surfaces in relative motion. Various approaches to achieving this state are considered in a broad sense, including structural superlubricity, superlubricity via normal force control, and contact actuation, as well as thermolubricity, liquid superlubricity, and quantum lubricity. An overview of the physical fundamentals associated with each approach is presented, with particular emphasis on recent theoretical and experimental developments that constitute milestones in our scientific understanding. The review also includes a discussion of perspectives on future research in the context of existing challenges. It is projected that interest in superlubricity from the basic science and engineering communities will continue to accelerate in the near future, accompanied by a transition from fundamental studies to technologically relevant applications.
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Progress in Superlubricity Across Different Media and Material Systems—A Review
Superlubricity is a terminology often used to describe a sliding regime in which the adhesion leading to friction or resistance to sliding literally vanishes. For improved energy security, environmental sustainability, and a decarbonized economy, achieving superlubric sliding surfaces in moving mechanical systems sounds very exciting, since friction adversely impacts the efficiency, durability, and environmental compatibility of many moving mechanical systems used in industrial sectors. Accordingly, scientists and engineers have been exploring new ways to achieve macroscale superlubricity through the use of advanced materials, coatings, and lubricants for many years. As a result of such concerted efforts, recent developments indicate that with the use of the right kinds of solids, liquids, and gases on or in the vicinity of sliding contact interfaces, one can indeed achieve friction coefficients well below 0.01. The friction coefficient below this threshold is commonly termed the superlubric sliding regime. Hopefully, these developments will foster further research in the field of superlubricity and will ultimately give rise to the industrial scale realization of nearly-frictionless mechanical systems consuming far less energy and causing much-reduced greenhouse gas emissions. This will ultimately have a substantial positive impact on the realization of economically and environmentally viable industrial practices supporting a decarbonized energy future. In this paper, we will provide an overview of recent progress in superlubricity research involving solid, liquid, and gaseous media and discuss the prospects for achieving superlubricity in engineering applications leading to greater efficiency, durability, environmental quality, and hence global sustainability.
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- Award ID(s):
- 2018132
- PAR ID:
- 10428634
- Date Published:
- Journal Name:
- Frontiers in Mechanical Engineering
- Volume:
- 8
- ISSN:
- 2297-3079
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3389/fmech.2022.908497
