Charge amplifiers for piezoelectric sensors

Research activities devoted to study and develop new piezoelectric tactile sensors for robotics show primary requirements of this class of sensor in terms of analog processing features. Charge amplifiers designed for this purpose are examined from the theoretical and experimental point of view showing performance data and limits in their application. A statistical approach has been adopted to validate experimental results obtained by testing a large number of devices. A new balanced circuit is proposed and analyzed to overcome the intrinsic disadvantages of the previous version of charge amplifiers. The experimental results obtained by testing the old and the new single-charge amplifier configuration show the benefits of adopting dedicated analog-processing structures for advanced piezoelectric sensors. Several considerations from the measurement and hybrid microelectronic point of view are presented