Whenever a curved surface interacts with another surface, the principles of adhesion are at work. From the cells in your body to the dust on your glasses, intermolecular forces cause materials to attract one another. Elastic deformations resulting from these adhesive interactions store strain that can be liberated during particle detachment. Time dependent changes in adhesion can result from plastic deformation that both increases the real effective contact area and reduces the stored energy available to assist in particle removal.