Active multifunctional composite metamaterials with negative effective mass density and negative effective modulus

•A composite metamaterial with controllable properties is presented.•Uses include vibration isolation, wave filtering, waveguides, negative refraction.•Can have negative effective mass density, negative effective modulus and ultralarge/negative Poisson’s ratio.•Effective longitudinal modulus is achieved by designed ultralarge effective Poisson's ratio structure with an absolute value greater than 1.•Can manipulate elastic waves using shunting circuits to achieve multiple functions without changing geometry. In this paper, a new composite metamaterial structure with negative effective mass density, negative effective modulus, and an ultralarge Poisson’s ratio is designed for vibration isolation, wave filtering, programmable construction of waveguides and negative refraction. This metamaterial can achieve vibration isolation in different frequency ranges using the shunting circuits. In two-dimensional metamaterial plate, a negative longitudinal modulus can be achieved by designing a model with an ultralarge Poisson’s ratio. This metamaterial can serve as wave filter when both shear and longitudinal waves are presented simultaneously. Wave propagation in the metamaterial can be controlled by switching of the shunting circuits. In this way, waveguides can be created programmatically. The phenomenon of negative refraction is also achieved in this metamaterial. Through control of the shunting circuits, this multifunctional metamaterial can be applied to vibration isolation, wave filtering, programmable waveguide construction, and negative refraction without changing its geometric structure.