The smallness of MEMS oscillators makes them an important platform for studying nonlinear phenomena. A unique feature, not shared by a harmonic system, is the dynamical steady state localization of some vibrations in driven nonlinear micromechanical lattices. Such an Intrinsic Localized Mode (ILM) is stable at any lattice site, and its position can be controlled by it interacting with an external field, a defect or another ILM. Both experiments and numerical simulations are used to explore the ILM-impurity attractive and repulsive interactions in micro-cantilever arrays in autoresonant states. The various findings reported here have a direct bearing on the application of nonlinear energy localization to implement smart functions in large-scale MEMS arrays.