Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Centre National De La Recherche Scientifique

Université Du Mans

Romain Liechti

Fabrice Casset

Stephane Durand

An electromechanical device includes at least one movable mechanical structure including at least one movable mechanical element; for each movable mechanical element of each movable mechanical structure a first piezoelectric layer, the first layer being disposed on a first part of the movable element so as to be able to actuate the movable mechanical element, and a second piezoelectric layer, the second layer being disposed on a second part of the movable element, distinct from the first part, so as to be able to convert mechanical energy associated with the movement of the movable mechanical element into electric energy, the layer forming a capacitance; the device further including an electrical circuit connected to the second piezoelectric layer in parallel with the capacitance formed by the layer and including an adjustable capacitance which can assume a negative value.

Variable resonant frequency electromechanical device and associated acoustic device

A micrometric speaker includes a frame, an electromechanical transducer, and a mechanical-acoustic transducer comprising a rigid plate movably mounted in the frame. The electromechanical transducer comprises two piezoelectric actuators and two elastic strips. The frame comprises a central crossmember from which the two strips extend until engaging two lateral coupling edges of the mechanical-acoustic transducer, and the mechanical-acoustic transducer comprises two linearising springs each extending from one of the lateral edges to the rigid plate, to enable, during a deformation of the strips, a movement of the two lateral edges to the central crossmember and reduce the longitudinal constraints applied to the strips during their deformation due to their 'recessed-guided' bending configuration.

Growing community of inventors

Grenoble, France

Romain Liechti