G10H 2220/551

Piezoelectric transducers for vibration sensing or vibration excitation in the audio range; Piezoelectric strain sensing, e.g. as key velocity sensor; Piezoelectric actuators, e.g. key actuation in response to a control voltage using piezoceramics, e.g. lead titanate [PbTiO3], zinc oxide [Zn2 O3], lithium niobate [LiNbO3], sodium tungstate [NaWO3], bismuth ferrite [BiFeO3] using LZT or PZT [lead-zirconate-titanate] piezoceramics [Pb[ZrxTi1-x]O3, 0=x=1]