Unlike conventional materials like metals, insulators and semiconductors etc. the smart materials are designed materials, whose properties can be engineered in several ways. Metamaterials appear under the class of smart materials, fabricated from assemblies of multiple elements from composite materials or plastics to exhibit specific electromagnetic or acoustic properties which are not observed in materials commonly found in nature.  Here we shall focus on one particular type: acoustic metamaterials (AMM).  Over the past decade there has been significant development in the field of acoustic metamaterials at the cutting edge of science and technology. AMM has many novel properties, which can be manipulated for unusual applications. In this talk I shall present a brief history of ‘metamaterials’ with particular emphasis on AMM. Like metamaterials for electromagnetic field, AMM has a special feature of double negative parameters in a band of frequencies in acoustic fields. These parameters in AMM are effective density and bulk modulus. Manipulation of these special properties leads to novel applications, which I shall highlight. An example of seismic waveguide of artificial AMM will be presented based on our recent work (to appear in Mod Phys Lett B 2017).

Mukunda Das is Honorary Professor in Theoretical Physics. He is Fellow of American Physical Society, Institute of Physics (UK) and Australian Institute of Physics. His research interest concerns the fundamental aspects of condensed matter, which include Superconductivity, Vortex Matter, Bose-Einstein Condensation, Meso- and Nanoscopic Systems, Strongly Correlated Electrons, Density Functional Theory and Theory of Disordered States. He is also interested in the professional ethics, an important subject of philosophy. He has been member of Editorial Board of many International Journals, namely- J. Physics: Condensed Matter (IOP)(2002-12), GSTF J of Physics and Applications, ANS J of Nano Sc and Nanotech (IOP), Inter. J Condensed Matter, Advanced Materials and Superconductivity Research, Nova Sc., New York and others.