University of Technology of Compiegne 1 article published in JoVE Engineering Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions Sven Drücker1, Isabell Krautstrunk2, Maria Paulick2, Khashayar Saleh1, Martin Morgeneyer1, Arno Kwade2 1Industrial Process Engineering, University of Technology of Compiègne, 2Institute for Particle Technology, Technische Universität Braunschweig The coefficient of restitution is a parameter that describes the loss of kinetic energy during collision. Here, a free-fall setup under vacuum conditions is developed to be able to determine the coefficient of restitution parameter for particles in micrometer range with high impact velocities.