What Is a Metamaterial?

Metamaterials get their properties not from their chemical composition but from their carefully designed internal structure — typically repeating patterns of metal or dielectric elements smaller than the wavelength of the waves they interact with. By engineering these structures, scientists can create materials with negative refractive index (bending light the wrong way), perfect absorption, or acoustic cloaking. Potential applications include invisibility cloaks (demonstrated at microwave frequencies), super-resolution lenses that beat the diffraction limit, and earthquake shields that redirect seismic waves around buildings. The field exploded after John Pendry proposed the theoretical basis in 2000.