This paper introduces a novel ultrasensitive resonant MEMS transducer with tunable electrostatic coupling, in order to measure micro-displacements induced stiffness perturbations. Enhanced sensitivity is achieved based on the principle of energy localization in eigenvalue veering phenomena, resulting from a symmetry breaking in coupled resonator systems. Experimental results from a coupled two-resonators MEMS device are compared with both analytical calculations, and Simulink model simulations. Modal vector sensitivity is shown to be an order of magnitude higher than resonant frequency sensitivity under ambient conditions. Decreasing the coupling strength between the two resonators, using tunable electrostatic spring, is shown to enhance sensitivity, albeit in a narrowed range of perturbations.