Vibration attenuation by means of piezoelectric transducer shunted to synthetic negative capacitance

This paper deals with vibration attenuation by use of piezo-actuators connected to a Negative Capacitance circuit, generally formed by a synthetic impedance based on operational amplifiers. The goal of this paper is to investigate the means to improve vibration attenuation performances and to avoid instability applying proper choices of the values of the electric elements composing the Negative Capacitance. This is accomplished using an analytic-numerical approach, which furthermore affords a full understanding of this technique. The paper also illustrates the mentioned instability problems at low-frequency and provides indications on how to avoid them. The results this way obtained are finally validated through experimental tests.