CHARGE AMPLIFIER DESIGN METHODOLOGY FOR PVDF-BASED TACTILE SENSORS

Abstract

This paper proposes and describes a charge amplifier-based interface electronics design methodology approach for piezoelectric polymer tactile sensors to be used for humanoid robot applications. The tactile sensor–consisting of a PVDF single sensor element–is illustrated, the electromechanical thickness mode behavior is modeled and a fabricated prototype is presented. The model allows associating the PVDF charge response to the effective load applied on the outer surface of the sensor. The model is also used as a key in the proposed design methodology to estimate the charge to be detected by the charge amplifier. A case study based on the design methodology approach is reported. The system (PVDF single taxel + interface electronics) is analyzed firstly, considering it as ideal and then when the nonidealities come into play. A charge amplifier-based interface electronics prototype is also presented. The implementation is used to validate the followed approach and then defining the design specs towards the dedicated IC design. Some experimental results are also reported.