Development of a Miniature Charge Amplifier for Quasi-static Strain Measurement with PVDF Piezoelectric Film Sensors

Polyvinylidene fluoride piezoelectric film sensors are gaining popularity in structural health monitoring due to their high sensitivity and flexibility. Accurate quasi-static measurements with PVDF sensors require a specialized charge amplifier. This paper presents the development of a miniaturized charge amplifier tailored for PVDF sensors, meeting the requirements for compactness while providing excellent quasi-static measurement performance. The proposed charge amplifier offers a gain of up to 100 times and a band-pass frequency range of 0.01 Hz to 200 kHz, comparable to existing commercial charge amplifiers, demonstrating strong performance. Experimental results validate the effectiveness of the developed system, showcasing its ability to capture quasi-static and low-frequency structural strains in real-time.