Programmable metamaterials with digital synthetic impedance circuits for vibration control

Abstract

This paper studies a new type of smart metamaterial consisting of piezoelectric actuators and digital synthetic impedance circuits (digital circuits). The digital circuit contains a micro-controller. By programming the micro-controller, the circuit can establish any desired impedance between the terminals of the connected piezoelectric patch, therefore to program the dynamical behaviors of the designed metamaterial. In this sense, a programmable metamaterial is studied. Experiments are conducted to study its programmable dynamical behaviors, with a particular focus on vibration reduction. Numerical simulations are also done in this work to qualitatively verify the experimental results. Different design methods are used to customize the dynamical behaviors of the designed metamaterial. Results demonstrate that the proposed smart metamaterial can be flexibly programmed online to reduce vibration at desired frequencies or within a large frequency band. The proposed programmable metamaterial conception can be naturally extended to other kinds of structures like plates and shells, they are promising components in the future adaptive structures.

Broadening low-frequency bandgaps in locally resonant piezoelectric metamaterials by negative capacitance

“…A more advanced way to realize shunts with L and NC is using programmable digital circuits [24]. A digital circuit usually is composed of voltage measuring block, digital signal processing (DSP) block and voltage controlled current source block.…”

“…This makes the circuit become more easy to be realized in practice since large analog inductance is difficult to obtain. Note that if the shunts are realized using digital techniques, large inductance value is no longer a problem [24].…”

“…Numerical and experimental results in their works demonstrate that the bandgap is broadened, but is still not wide enough. The conception of varying shunts' parameters gradually in space to create "rainbow traps" is explored in [23,24]. This kind of design shows good effects in increasing bandgap ranges, but the number of unit cells needed to realize a "rainbow trap" with acceptable wave isolation level could be large.…”

Electromechanical active metamaterials and their applications in controlling elastic wave propagation

“…Yi 等人 [76] 果 [76] . Figure 7 Programmable electromechanical metamaterials and their applications in vibration reduction.…”

“…Figure 7 Programmable electromechanical metamaterials and their applications in vibration reduction. (a) A digital programmable metamaterial beam; (b) the controllable bandgap effects [76] .…”