It is well-known that sound wave carries dynamical phase during propagation. A latest research conducted by researcher from City University of Hong Kong (CityU) and his collaborators from other universities has demonstrated a new type of phase of sound: the spin-redirection geometric phase.

A research team led by Professor Paul Chu Kim-ho, a materials engineering expert at City University of Hong Kong (CityU), has developed a capacitive coating that kills bacteria when it is charged with electricity. When applied to orthopedic implants such as artificial joints and dental implants, the novel technology can reduce the risk of infection after surgery and help patients recover more quickly.