Biocompatible, implantable hearing aid microactuator

Abstract

A biocompatible, implantable microactuator (82) for a fully implantable hearing aid system includes a hollow body (84) that has an open first end (88) and, open first and second faces (94a and 94b). Flexible diaphragms (92, 96a and 96b), respectively covering the end (88) and faces (94a and 94b), hermetically seal the body (84). An incompressible liquid (98) fills the body (84). Transducers (102), provided by laminated, stress-biased unimorphs (32 or 62) that are mechanically coupled to the flexible diaphragms (96a and 96b), deflect the diaphragms (96a and 96b) in response to an electrical driving signal. Deflections of the diaphragms (96a and 96b) are coupled by the liquid (98) to the first flexible diaphragm (92). The unimorphs (32 or 62) include a layer of biocompatible metal (36 or 66-68) deposited on one side of a biocompatible piezoelectric ceramic plate (34 or 64) to stress-bias the plate (34 or 64). A thin, biocompatible electrode (44 or 72) coats the other side of the plate (34 or 64).

Dependencies are inferred from the claim text.