Esedoglu, SelimRätz, AndreasRöger, Matthias2012-10-012012-10-012012-10-01http://hdl.handle.net/2003/2965310.17877/DE290R-10567This paper is concerned with diffuse-interface approximations of the Willmore flow. We first present numerical results of standard diffuse-interface models for colliding one dimensional interfaces. In such a scenario evolutions towards interfaces with corners can occur that do not necessarily describe the adequate sharp-interface dynamics. We therefore propose and investigate alternative diffuse-interface approximations that lead to a different and more regular behavior if interfaces collide. These dynamics are derived from approximate energies that converge to the L1-lower-semicontinuous envelope of the Willmore energy, which is in general not true for the more standard Willmore approximation.enMathematical Preprints ; 16/2012610preprint