Structured geometry surfaces features for optimised function

With the deepening understanding of the importance of the surface and its properties on the function of engineering components there has been an increasing focus on "designing" the surface topography to optimise functionality. Increasingly this "design" aspect of surfaces has taken the form of giving the surface a clearly defined topographical structure or surface micro geometry. The aim of the surface structure is to ensure specific surface properties which enhance or even define the surface functionality. Such structures are not necessarily new and plateau honing of automotive cylinder liners is a clear example of a traditional process where bearing and lubrication transport and retention properties are enhanced. The latest developments in the applications of structured surfaces cover functionality as wide as enhanced tribological properties, tailored optical properties and optimised bio cellular attachment. The features on the functional surfaces are usually defined geometrical structures such as craters with specific volume and spacing or protuberances having fixed geometries heights and spacing. The concept of structured surfaces is introduced in this review paper along with examples of the application of surface structures in the fields of injection moulded optics, bio implant attachment and enhanced tribological properties. The surface structures are discussed in terms of the improved properties and the challenging aspects of modelling function and their measurement and characterisation.