Ongoing externally funded projects

Scaling Superlubricity into Persistence, SSLiP (EIC Pathfinder) on developing a way to utilise the atomic-level effect of structural superlubricity in macroscopic tribological systems.

Friction between moving parts and the associated wear are estimated to be directly responsible for 25% of the world's energy consumption. SSLiP seeks to establish a radically new way to drastically reduce friction, with potentially enormous technological and societal impact. The driving concept is structural superlubricity, extremely low friction that takes place at a lattice misfit between clean, flat, rigid crystalline surfaces. Structural superlubricity is currently a lab curiosity limited to micrometer scale and laboratory times. SSLiP will bring this to the macroscale to impact real-life products. The key idea is the use of tribo-colloids: colloidal particles coated in 2D materials, that will produce a dynamic network of superlubric contacts. Structural incompatibility between arrays of colloids allows us to replicate the low friction on bigger length scales and overcome the statistical roughness of real surfaces. We will leverage our breakthrough result to regenerate the 2D coatings themselves during sliding. Through careful design of these coatings, carrier fluid, and the mechanical properties of the core particles, the chemistry of sliding and collective behaviour of the colloids can be controlled. Synthesis and experiments of individual contacts will be combined with visualisation of colloid dynamics during sliding on larger scales and in-site chemical characterisation. These will be combined with multiscale simulations and theory to bridge the different length scales into a coherent framework. The developed ultra-low friction technology will drastically reduce loss of energy, for example in passenger cars (responsible for around 2 billion tonnes of CO2 per year) and increase the lifetime of parts. It will also enable radically new technologies that are impossible with current lubrication, thus paving the way for e.g. much higher writing speeds in harddisks, where the writing tip will be able to move in full contact with the disk.

Sustainable Stable Ground/Bærekraftig Grunn, SSG (Research Council Norway) on stabilisation of quick clay.

Soft soil, such as marine clay, gives challenging conditions for infrastructure development in many places in the world, which requires enormous amounts of ground stabilization. In Norway the major challenge is quick-clay (non-swelling illite). Due to the cost effectiveness, ground improvement with lime-cement stabilization using deep-mixing technology is widely used. However, considering the huge amount of lime and cement used in ground improvement projects and the carbon intensity of lime and cement production, the contribution from these geotechnical works, to the carbon inventory of large infrastructure projects in Norway (and in the world in general), is very high. Many times, it is the largest single contributor. At the same time waste from concrete and bricks, and ashes are the largest contributors to the masses being deposited in Norway. These materials have a great potential as additives in the stabilizing technology.

We aim to radically change the deep-mixing technology by introducing sustainable alternative stabilizers based on solid wastes and creating a circular economy around this technology.

To achieve this goal, we need interdisciplinary research with a bottom-up combined experimental and modelling approach, across the scales and disciplines. At nano and sub-nano scale, we will employ a combination of numerical and experimental work starting with the water and ions interactions at illite-clay particle surfaces. At micro scale, we will combine thermodynamic modelling with experiments to investigate how the interactions between illite-clay and cementitious materials contribute to the microstructure and strength development. At macro scale, representative elements of stabilized clay will be tested and full-scale geotechnical problems simulated. Finally, we will calculate and compare the total environmental impacts of the alternative technologies.

Viscosity of complex polar fluids, electrolytes, and ionic liquids (Research Council Norway).

This project is concerned with the transport properties, especially the viscosity, of electrolyte systems: aqueous electrolyte (salt) solutions and ionic liquids (liquid electrolytes). These systems are becoming a new frontier in friction research and are very promising for low-friction applications, as demonstrated for instance by the amazing effectiveness with which water-based synovial fluid lubricates our joints. Development and implementation of new technologies, however, is blocked by our lack of systematic theoretical understanding. We do not yet have sufficient understanding of the viscosity of these complex liquids to be able to control it. The aim of this project is to remedy this situation and develop general understanding and practical methods for calculating the viscosity of electrolyte systems.

The challenge lies in the large number of parameters and the complicated dynamics that result from the presence of electrostatic interactions. As a result, theoretical work has so far been limited to detailed atomistic simulations. These are extremely demanding and can only give insight into specific systems, but it is simply not feasible to simulate enough different systems to deduce general trends. This project will instead use a more challenging but ultimately much more powerful analytical approach based on kinetic theory of fluids. New theory will be developed and used to compute viscosities of complex electrolyte liquids. The theoretical development will be combined with simulations of simple model fluids that will be used to test the validity of approximations and check results. Along with this, there will be close interaction with experimental and theoretical groups in Stockholm and at Imperial College London.