Auxetic mechanical metamaterials and their futuristic developments: A state-of-art review

The continuous advancement of multifunctional materials is reshaping our way of life and paving the door for innovative things for us to probe the world and ourselves. Multifunctional Auxetic Mechanical Metamaterials (AMMs) have emerged in recent years, endowing them with innovative mechanical properties and multi functionalities, presenting a great way to transform numerous industries. Favour of peculiar mechanical deformation mechanisms, fabrication processes steer to novel Multiphysics properties such as synclastic, variable permeability, indentation resistance and shape memory. AMM's potential applications span a wide range of industries, including apparel, automobiles, aeroplanes, pharmaceuticals, military applications, sports and protective wear, biomedical systems, smart sensing materials, and more. However, due to complicated manufacturing and a lack of structural stability, most functional applications remain in the theoretical phase. There is a substantial vacuum to fill and resolve for reducing barriers to practical applications, which has been plentiful in the last decades through discoveries of materials and production processes and functional applications. We discussed the futuristic auxetic structure, manufacturing techniques, fabrication materials, and future applications of AMM. We also addressed current issues and future research directions, intending to state the vision and inspire research communities to evolve the AMM.