A research team from VTT Technical Research Centre of Finland has demonstrated that the energy needed to produce a new surface has no connection with the surface tension on solid materials. As a result, surface tension on a solid material does not exist.
In general, it is believed that a surplus surface stress exists on solids, which is similar to that on liquids. The Shuttleworth equation, a fundamental equation of surface thermodynamics, has explained the surface tension over 60 years ago and it is considered that there is a connection between the surface tension and the energy.
Three years ago, Lasse Makkonen and Kari Kolari from VIT and David Bottomley, a British scientist, have jointly revealed the incompatibility of the Shuttleworth equation with the thermodynamic theory in the Surface Science journal. However, the new research by Lasse Makkonen has mathematically shown that the disputed equation minimizes to the description of mechanical surface stress and reveals no link with the energy needed to create a new, unstrained surface. As a result, the scientists have shown the nonexistence of excess surface tension described by the Shuttleworth equation, and that the existence of surface stress on a solid material is required by molecular dynamics only at the surface layer. Thus, VIT researchers provide a new definition of surface tension on solid materials.