The field of nano-electromechanics explores the interaction of excitations in an electrical circuit with a displacement of a nano-mechanical object. The resulting sensing concept allows to investigate quantum mechanical phenomena in the literal sense, while interaction itself can be harnessed to synthesize quantum states in the electrical and mechanical entity. We realize nano-electromechanical systems in the form of nano-strings coupled to superconducting quantum circuits. The displacement of the nano-string controls the resonance frequency of the superconducting microwave circuit, realizing this interaction. While this coupling concept is vastly utilized in sensing applications ranging from simple force sensors to gravitational wave detectors, the nature of the coupling also allows for controlling and preparing mechanical oscillation states down to the quantum regime.