Topology optimization has shown great promise in designing multi-material structures to exploit the potential of lightweight structures. The interfacial behavior between the different phases of a multi-material structure is critical to designing such structures, but current topology optimization methods have not adequately addressed it. The difficulties may arise from three aspects: first, the difficulty of tracking interfaces in topology iterations; second, the difficulty of characterizing interface properties; and third, the difficulty of qualitative and quantitative interface behaviors. In this talk, we introduce an energy-based approach to improve the interface configuration for multi-material topology optimization. The idea comes from the fact that multi-material interfaces often exhibit asymmetric tensile and compressive resistance. In the density-based topology optimization framework, a gradient-based approach is used to track the interface between multiple materials. We first compute the elastic strain energy of the structure in a linear elastic manner and split it into tensile and compressive components based on the strain spectral decomposition. Then, we construct an interface-associated scalar field to penalize the tensile portion of the strain energy, thereby inducing a pseudo-degradation of the strain energy in the interface region. Finally, within limited material usages and by minimizing the linear-weighted structural strain energy and its pseudo-degradation, multi-material topology optimization with improved interface configuration is achieved. We validate this approach through both 2D and 3D numerical examples. It is found that the suggested approach is effective and robust to incorporate interfacial effects in multi-material topology optimization.