Patent ID: 8513859

Claim:
An interactive panel comprising: a substrate wherein a seismic wave is intended to propagate according to a direction of propagation; at least two piezoelectric transduction devices; each piezoelectric transduction device comprising two piezoelectric transducers; each piezoelectric transducer comprising two piezoelectric elements each having two surfaces each covered by an electrode, a central axis being located between the two piezoelectric elements, with the four electrodes of each piezoelectric transducer being interconnected to supply, when opposing stresses on either side of a stress-separation plane, comprising the central axis, are applied to the piezoelectric elements of this transducer, an electrical measurement signal that depends on the angle between a main plane, proper to the piezoelectric transducer and the stress-separation plane; the two piezoelectric transducers of a same piezoelectric transduction device have the same central axis and their respective main planes form a non-zero angle thereinbetween; and each piezoelectric transduction device is attached to the substrate such that movement of the substrate during passage of the seismic wave causes stress on the piezoelectric elements, in opposite directions on either side of the stress-separation plane, with the separation plane depending on the direction of propagation.