An Experimental Study of a Piezoelectric Metastructure With Adaptive Resonant Shunt Circuits

There is a growing interest for research toward enabling on-demand reconfigurable and readjustable metastructures with dynamic response tailoring capabilities. In this article, a metastructure with piezoelectric unit cells shunted to self-tuning resonant circuits is experimentally explored to enable adaptive behavior in the resulting system dynamics with focus on vibration attenuation. Synthetic inductor circuits are combined with digital potentiometers to enable real-time tuning of the resonant shunts. A microcontroller unit was employed to detect the excitation frequency and properly adjust the resonant circuits. Experimental results are presented for a base-excited, locally resonant, piezoelectric plate following a discussion of the adaptive circuit. For a certain metamaterial configuration, a broad suppression range (102-622 Hz) was observed. The bandwidth of 520 Hz (84% of the upper limiting frequency) could be increased according to the electrical elements of the adaptive circuit.