Shear piezoelectric transducer

An energy harvesting device comprising a plurality of the piezoelectric transducers, wherein each piezoelectric transducer comprises:

• a piezoelectric foil with a piezoelectric material exhibiting a shear piezoelectric effect, wherein the piezoelectric material is polarized in a polarization direction in a plane with the piezoelectric foil to generate an electric field in a field direction normal to the plane of the piezoelectric foil between a top surface and a bottom surface of the piezoelectric foil when the piezoelectric foil is sheared in the plane of the piezoelectric foil in a shearing direction about the field direction;
• and
• an actuating structure configured to actuate the piezoelectric foil with actuation forces applied at respective actuation points in respective actuation directions to bend the piezoelectric foil,
• wherein the actuating structure is configured to actuate the piezoelectric foil according to a saddle shape deformation,
• wherein the piezoelectric foil is bent in two opposing bending directions, and
• wherein the two bending directions are orthogonal to each other and are both diagonal to the polarization direction.

A sensor comprising one or more piezoelectric transducers, wherein each piezoelectric transducer comprises:

• a piezoelectric foil with a piezoelectric material exhibiting a shear piezoelectric effect, wherein the piezoelectric material is polarized in a polarization direction in a plane with the piezoelectric foil to generate an electric field in a field direction normal to the plane of the piezoelectric foil between a top surface and a bottom surface of the piezoelectric foil when the piezoelectric foil is sheared in the plane of the piezoelectric foil in a shearing direction about the field direction;
• and
• an actuating structure configured to actuate the piezoelectric foil with actuation forces applied at respective actuation points in respective actuation directions to bend the piezoelectric foil,
• wherein the actuating structure is configured to actuate the piezoelectric foil according to a saddle shape deformation,
• wherein the piezoelectric foil is bent in two opposing bending directions, and
• wherein the two bending directions are orthogonal to each other and are both diagonal to the polarization direction.