At the 17th of June 2011 the 7th Arnold Tross Colloquium was held. It took place at the Institute of Engineering Design and Product Development (IKP) and connected university research and industry research.A wide range of topics were presented. From nano to macro scale, from real machine elements and new test devices to fundamental investigations.Two papers were based on the so called Energetical Approach of Tribology (EAT).