摘要
More than two decades ago,the experimental demonstration of negative refraction in an artificial structure represented a materials science breakthrough of the 21st century.It is not only an exotic phenomenon beyond the common sense,but also opens up some unprecedented capabilities and functionalities(e.g.,super-lens).Since then,the concept“Metamaterials”gained considerable attentions,initially in electromagnetic waves and eventually expanded to differentfields,such as optics,acoustics,mechanics,as well as technologies like communication,medical equipment,vibration isolation and energy harvesting,to name a few.
