An ink jet apparatus applies a drive voltage to electrodes formed on portions of side walls made of piezoelectric ceramics and varies the internal volumes of grooves adjacent to the side walls using the action of a deformation produced by a piezoelectric thickness/slip effect of the piezoelectric ceramics....http://www.google.com.au/patents/US5657063?utm_source=gb-gplus-sharePatent US5657063 - Ink jet apparatus
