US 12,470,876 B2
Variable resonant frequency electromechanical device and associated acoustic device
Romain Liechti, Grenoble (FR); and Fabrice Casset, Grenoble (FR)
Assigned to COMMISSARIAT À L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Filed by COMMISSARIAT À L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Filed on Dec. 5, 2023, as Appl. No. 18/529,717.
Claims priority of application No. 2213178 (FR), filed on Dec. 12, 2022.
Prior Publication US 2024/0196136 A1, Jun. 13, 2024
Int. Cl. H04R 17/10 (2006.01); H04R 17/00 (2006.01)
CPC H04R 17/10 (2013.01) [H04R 17/005 (2013.01); H04R 2201/003 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An electromechanical device comprising:
at least one movable mechanical structure comprising at least one movable mechanical element;
for each movable mechanical element of each movable mechanical structure:
a first piezoelectric layer, said first piezoelectric layer being disposed on a first part of the movable element so as to be able to actuate said movable mechanical element;
a second piezoelectric layer, said second piezoelectric 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 a movement of the movable mechanical element into electric energy, said second piezoelectric layer forming a capacitance, and
an electrical circuit connected to the second piezoelectric layer in parallel with the capacitance formed by said second piezoelectric layer and including an adjustable capacitance which is adapted to assume a negative value.