These papers represent the proceedings from the 29th Leeds-Lyon Symposium on Tribology, 'Tribological Research and Design for Engineering Systems' which was held in September 2002. Over 130 delegates from 18 countries attended the symposium, and the extensive discussions generated over 150 written questions and responses, which are documented at the end of this proceedings volume. There have been many advances in the field of tribology in recent years, with progress being made in the engineering and interaction of surfaces; micro and nano-tribology; elastohydrodynamics; surface films; surface.

This collection of fully peer-reviewed papers were presented at the 26th Leeds-Lyon Tribology Symposium which was held in Leeds, UK, 14-17 September, 1999. The Leeds-Lyon Symposia on Tribology were launched in 1974, and the large number of references to original work published in the Proceedings over many years confirms the quality of the published papers. It also indicates that the volumes have served their purpose and become a recognised feature of the tribological literature.

This year's title is 'Thinning Films and Tribological Interfaces', and the papers cover practical applications of tribological solutions in a wide range of situations.

The evolution of a full peer review process has been evident for a number of years. An important feature of the Leeds-Lyon Symposia is the presentation of current research findings. This remains an essential feature of the meetings, but for the 26th Symposium authors were invited to submit their papers for review a few weeks in advance of the Symposium. This provided an opportunity to discuss recommendations for modifications with the authors.

The 24th Leeds-Lyon Symposium was held in London from 4th-6th September 1997, where it was hosted by the Imperial College of Science, Technology and Medicine.The meeting addressed the topic of "Tribology for Energy Conservation" and attracted a wide range of stimulating papers and speakers. Some 150 delegates from nineteen countries attended and about sixty papers were presented in fifteen sessions. These covered the topics of lubricants, wear, friction reduction, hydrodynamics, elastohydrodynamic lubrication, surface roughness, manufacturing, component life (including condition monitoring), and automotive aspects.

The 25th Leeds-Lyon Symposium on Tribology was held at the Institut des Sciences Appliquees de Lyon, from 8-11th September, 1998. Its central theme was, "Lubrication at the frontier: the role of the interface and surface layers in the thin film and boundary regime". This topic was chosen because it represents an important evolution of the research field.
The Symposium opened with a keynote address entitled "Role of surface-anchored polymer chains in polymer friction" which described the processes taking place at the interface between "solid" and "liquid". The keynote address was followed by two invited lectures. Firstly, "Fuel efficient engine oils, additive interactions, boundary friction and wear" presented the industrial point of view on lubricant formulation and engine testing and its evolution. The second lecture was entitled "For establishment of a new EHL theory" and stressed the need to extend the current EHL theory.
Beginning in 1974, The Leeds-Lyon Symposia have now covered a wide range of topics. The essential aim each year is to select a topic of current interest to tribologists and to contribute to further the advance of knowledge in selected fields.