Understanding and Controlling Nano and Mesoscale Friction

Recent years have seen widespread efforts to understand the mechanisms of friction and tribology in micrometric structures (mesoscale) down to the realm of atoms and molecules (nanoscale), with the ultimate goal of controlling friction, adhesion and wear by design. This research has generated an interdisciplinary scientific area, nanotribology, with great potential impact on technology and everyday life. Applications include safety, economy, life quality, energy and material saving, toward a sustainable development. Europe has a strong scientific nanotribology community spreading over physics, materials science, chemistry, earth and life sciences. So far, this community lacks a chance to interact closely enough: it is in urgent need of better networking, to favor collaboration among groups and exchange of complementary expertise. A COST Action, operating beyond the national horizons, can indeed mobilize and put together the critical mass of existing human and technical nanotribology resources at a modest price, thus representing a unique opportunity for an efficient scientific investment.

Our specialization

Multiscale Tribological Processes

Control of Friction Wear and Adhesion

Nanotribology

Nanomanipulation

Confined Lubricants and Boundary Lubrication

GENERAL BACKGROUND

Friction is an everyday issue. At micrometric and sub-micrometric scales, interfacial forces dominate: friction and adhesion forces affect the performance and lifetime of microdevices such as magnetic-storage hard disks, micro/nano electromechanical devices (MEMS/NEMS). Durable low-friction surfaces, wear-resistant materials, and suitable liquid and solid lubricants are in demand for hi-tech applications. A fundamental understanding of the elementary nanotribological mechanisms, intimay related to both adhesion and wear, and the interrelated collective mesoscopic processes is still in its infancy, and remains a challenge. If a better understanding of atomic-scale frictional processes could be extended to the macroscopic scale of machinery, it could lead to progress in transportation, manufacturing, energy conversion, and lubricant consumption, impacting on innumerable aspects of our economy, health and environment. Methods beyond lubrication for the reduction and control of friction are needed, and promise significant industrial impact.

Europe has a highly productive and scientifically visible nanotribological community, encompassing at least 30 groups with strong expertise, covering experimental, theoretical, and simulation approaches. This community is a patrimony, comparable to its US and Japanese counterparts. American nanotribologists are naturally pulled together by the necessity to network and to concur for funding. There are Gordon Conferences, American Physical Society (APS) March Meeting Focused Symposia, and other occasions where their community joins forces. The same can be qualitatively said for Japan. In contrast, the European nanotribology community is missing a systematic EU-funded effort supporting contacts and networking. Several COST countries contribute individually national funds to micro/nanotribology research, and so does the EU, e.g. through a number of individual European Research Council (ERC) grants. None of these covers European networking, though.

This Action will fill this gap. It will be complementary to existing national research programs, not duplicating any. Its scope will be to help all European groups active in nanotribology to network together, thus fostering a concerted scientific effort.

Aim

The aim of the Action is to strengthen, organize, and merge scientific and technological competencies in the field of micro/nanotribology at an European level, by means of the integration of research capacities which are nowadays nationally and thematically fragmented, especially in such a wide and multidisciplinary area as friction at the micro- and nano-scale. The better coordinated research will lead to innovative solutions to, e.g., the industrial problems of hi-tech companies, such as novel coatings and molecular lubrication strategies.

Objectives

• 1. Coordinate the present activities and stimulate innovation.

  The first objective of the present Action is to overcome the fragmentation of the nanofriction community by merging diverse skills into coherent interdisciplinary approaches, to boost interactions and collaborations among scientists. This Action will certainly lead to approximay 100 joint publications in the period of the Action but, more importantly, will make new insights emerge and stimulate creativity.

• 2. Support gender balance and involvement of ESR.

  Early-stage researchers will be provided with broad international perspectives for their scientific career. The underrepresentation of women in the hard sciences is exacerbated by the fragmentation of nanotribology research: there are several women but they are scattered across the continent and across sub-areas with little contact. This Action will provide vital opportunities to network together, vigorously promoting the participation of women scientists in all Action activities. This will encourage particularly young women scientists who will have an opportunity to interact with all senior scientists, in particular women active in their field through Action events.

• 3. Promote dissemination and advertising within and outside the Action.

  Exchange and dissemination of results are crucial coordinating the research among the units, advancing the field, interacting with other communities, and for increased visibility in the global scientific arena. This is crucial at the political level too. A problem which nanotribology research faces is that it is not adequay represented in European scientific policies and programmes. Effective dissemination and advertising of the scientific achievements in this field will improve the awareness of European policies of the role of tribological research in the advancement of science and technology.

• 4. Team up and prepare applications for future joint training and research projects.

  Europe offers several schemes for funding joint activities, e.g. the Initial Training Network (ITN), under the Marie-Curie actions of the VII Framework Programme or new actions within Horizon 2020. Since national funding schemes rarely support international events and cooperation, European funding programmes acquire in this respect a central role because they cover a much broader scale. The present Action aims at developing strategies for the successful participation in future funding programmes and for preparing future proposals, in order to give continuity and to build on the scientific success of the nanotribology network.

  Scientific focus

   

  A better microscopic understanding and control of friction guides the scientific focus of this Action, which addresses the following tasks:

• Drawing bridges between friction at different scales and properly relating the atomistic processes with the macroscopically observed effects.
• Controlling the tribological behaviour by imposing, e.g., tiny mechanical oscillations or by exploiting either natural surface geometries or externally induced interfacial nanostructures.
• Exploring confined interfaces under shearing. These tribological systems exhibit intriguing boundary lubricated regimes, whose tunability represents a priority for a variety of micromechanical devices where the early stages of motion and the stopping processes are often dominated by highly dissipative stick-slip dynamics.
• Understanding the diffusion, adhesion and friction mechanisms of atomic or molecular aggregates on surfaces. Single-cluster manipulation can serve as an ideal method to measure the interfacial friction of structurally well-defined contacts of controlled sizes and material pairings.
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• _{^{cordination and organisation}}

• The Action will be supervised and coordinated by a Management Committee (MC), presided by a Chair and a Vice-Chair, according to document COST “Rules and procedures for implementing COST Actions”. All research activities of the Action members will be carried out and funded by internal resources of the participating groups, with COST supporting only the coordination, networking, and dissemination activities. To achieve the Action objectives effectively, coordination will involve:

• Action management
  The MC will set up the network, discuss the achievements and the problems encountered, and plan future activities. It will report to the COST Office on a yearly basis. The MC will appoint a Core Group (CG) to assure rapid, efficient and flexible coordination of the Action. The CG will consist of the MC Chair and vice-Chair, the WG Leaders, the STSM Coordinator, and the Gender Balance Coordinator. The CG will prepare all relevant documents for the MC meetings.
• Outreach Coordination
  The MC will appoint a Coordinator responsible to create and update monthly the Action web site according to COST rules, and to publish a periodic newsletter, with scientific highlights, joint publications, and job advertisement. The Outreach Coordinator will also supervise the other activities described in section H.
• Gender balance and mentoring
  The MC will appoint a Gender Balance Coordinator to promote an appropriate gender balance in all Action-related activities and coordinating the mentoring scheme for early-stage researchers.
• STSMs Coordinator
  She/he will coordinate the STSMs. She/he will be responsible of overseeing the STSM-implementation plan, prepare the annual selection and review process of the STSMs. Operative decisions on the STSM will be taken by the CG and reported to the MC.

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  Working Groups

  The four WGs detailed in this page will target the four main investigation streams outlined in section B.2. Each WG will be coordinated by a chair and a vice-chair appointed by the MC, with the responsibility for organization, coordination, networking and reporting. WGs will also provide the scientific input to the annual reports and the periodic outreach activity.

  The scientific programmes of the four WGs will be carried out in close cross-correlation. The participation of groups in more than one WG will be encouraged. The existing cross-links between WGs will extend in the course of the Action, thus maximizing the impact of the Action itself. An upgrade of the WG structure may be implemented at the mid-term meeting, if the MC identifies clear benefits for the on-going Action plan.

  Liaison and interaction with other research programmes

  To establish fruitful possible interactions with future interrelated COST Actions and other European or worldwide research programmes, the following means will be exploited:

• organization of seminars and joint workshops/meetings, as an effective means of exchange;
• invitation of leading academic and industrial partners of other programmes to talk at the annual Action conferences/workshops;
• establishment of research collaborations, especially through joint European projects to study specific topics of common interest;
• invitation to join this COST Action, directed to groups of those projects with relevance for the tribology field.

• An objective of the Action is to promote the participation of its members in future research programmes, in particular, those launched within the European Framework Programmes.

  Gender balance and involvement of early-stage researchers

  This Action will respect an appropriate gender balance in all its activities and the Management Committee will place this as a standard item on all its MC agendas. The Action will also be committed to considerably involve early-stage researchers. This item will also be placed as a standard item on all MC agendas.

  As the number of women working in tribology is traditionally small, this Action will devote an extra effort in supporting a gender balance in all its activities. The MC will implement a mentoring programme; the website and the newsletters will highlight events concerning gender issues and women in science. This Action will also encourage and support the participation of young researchers to all Action activities as well as in its management and administration.