Dr Bo Persson

Bo Persson was born in Sweden and studied Physics at Chalmers University in Gőteborg, obtaining his PhD on the dynamical processes at surfaces in 1980. He undertook postdoctoral work at the Forschungszentrum Julich, and at the IBM Yorktown Heights Research Lab before returning to Julich in 1983. Bo has collaborated with countless theoretical and experimental groups worldwide, and has had research visits to Brookhaven National Lab, Oak Ridge National Lab, ICTP Trieste, and ITP Santa Barbara. He spent one year as visiting scientist at the IBM Zurich Research Lab and another year at the University of Toyama, Japan.

Bo Persson has written a seminal book on tribology, Sliding Friction: Physical Principle and Applications, which appeared in the late 1990s. This work showed how far our understanding of tribology fundamentals had evolved since Bowden and Tabor, thanks to the extraordinary experimental, theoretical and computational developments that had taken place in the intervening decades. For his contribution to surface physics, he was awarded the Volvo prize in 1980, the prestigious Walter Schottky Award of the German Physical Society in 1996, and the John Yarwood Memorial Medal in 1997.

In 2000 he wrote the paper Theory of rubber friction and contact mechanics, which turned out to be very fundamental. This multiscale contact mechanics theory resulted from an insight that came to him on the time scale of seconds, but working out all the consequences and applications occupied Bo Persson for the next 20 years. This theory tackles what is possibly the most central and challenging problem in tribololgy, namely the way in which the random surface roughness of real surfaces influences the way in which they contact each other. The Persson Theory involves considering surfaces at different levels of magnification, and determining how quantities, such as contact area, the probability distribution of stress and of interfacial separations, change with the magnification. Crucially, the theory shows the importance of including long-range elastic coupling between asperity contacts which was neglected in all earlier contact mechanics theories.

The Persson Theory has found applications in such practically important areas as:

• Contact mechanics for elastic/viscoelastic and elastoplastic systems
• Contact mechanics of layered materials
• Adhesion, including capillary adhesion
• Thermal and electric contact resistance
• Rubber friction
• Leak-rate of seals
• Fluid squeeze-out between rough elastic surfaces
• Elastohydrodynamics with mixed lubrication
• Contact phenomena on human skin
• Bioadhesion, in particular Gecko and Tree Frog adhesion
• Contact phenomena on cellulose fibres

Persson has published seminal studies in all of these areas. He has also pioneered studies of non-contact (vacuum) friction and heat transfer, and coauthored a book with Prof. Volokitin, Electromagnetic Fluctuations at the Nanoscale, published 2017. The industrial importance of many of these topics led Persson first to work as a consultant for tyre companies, where understanding the origin and the nature of rubber friction on dry and wet road surfaces is absolutely essential. He continues to publish heavily, expanding our understanding of contact throughout all facets of our diverse field. It is difficult to think of a more deserving candidate to receive the Tribology Gold Medal.