Engineered metasurfaces reflect waves in unusual directions
(PHYSorg.com Physics)

In our daily lives, we can find many examples of manipulation of reflected waves, such as mirrors, or reflective surfaces for sound that improve auditorium acoustics. When a wave impinges on a reflective surface with a certain angle of incidence and the energy is sent back, the angle of reflection is equal to the angle of incidence. This classical reflection law is valid for any homogenous surface. Researchers at Aalto University have developed new metasurfaces for the arbitrary manipulation of reflected waves, essentially breaking the law to engineer the reflection of a surface at will.