The PhD project focuses on micro or nanomechanical resonators and their surrounding electronics environment. Mechanical components are employed to sense masses in the attogram range (10−18 g) or extremely low gas concentrations. The components can then be implemented in arrays in order to construct cutting-edge mass spectrometers or gas chromatographs. To reach the necessary resolutions, a harmonic detection of resonance technique is employed that measures the shift of the resonant frequency of a tiny mechanical structure due to an added mass or a gas adsorption. The need of shrinking the resonator's dimensions to enhance the sensitivity also reduces the signal delivered by the component. The resonator low output signal requires employing new electromechanical resonator topologies and electronic architectures that minimize the noise, the parasitic couplings and that can be implemented in arrays.