A linear resonant actuator includes: (a) an electromechanical polymer (EMP) actuator; (b) a substrate having a first surface and a second surface, the EMP actuator being mounted on the first surface of the substrate; (c) clamping structure provided on two sides of the substrate so as to allow the substrate to vibrate freely between the two sides of the substrate, in response to an electrical stimulation of the EMP actuator; and (d) an inertial mass element having a contact surface for attaching to the substrate at the second surface of the substrate. The inertial mass element may include contact structures provided to attach to the substrate along thin parallel lines. In one embodiment, the inertial mass element may have a “T” shape, or any suitable shape for stability.