A microstructure that may be used as an acoustic source or receiver. It comprises a substrate having a thicker section and a thinner section, supporting a membrane. A window is formed in the thinner section. Means are provided for inputting or sensing mechanical energy in the substrate and membrane....http://www.google.fr/patents/US5569968?utm_source=gb-gplus-shareBrevet US5569968 - Microfabricated acoustic source and receiver
