Paper Title
Characterization of Muscle Contraction Force Gradient Using Piezoelectricity – Part II

Abstract
In this paperanon-invasive sensor technology for reliable measurement of muscular contraction analysisis setup. It is based on piezoelectric materials because they produce electricity when they are folded. The article developsan electronic system to be fixed on the skin for direct measurements anddiscusses the relevance of the results as sensors for prosthetic members or other controlling systems. The system utilizes the skin surface modifications due to muscular contraction. To get the signal from the piezoelectric patch, a low pass analogic filter isdeveloped with a resistance and capacitor circuit. An ideal diode playing the role of a peak revelator iscreated with the help of an operational amplifier and diode circuit. The amplitude output of the piezoelectric patch being of the order of a millivolt, a non-inverting amplifier enhances the signal at the end of the circuit. To visualize the output of the patch folded by patient muscle, a display shows the curvature angle of the patch computed by an Arduino Uno board. Experimental results show the reliability of the system in terms of ergonomics and transparency. Keywords - Non-invasive Sensor, Piezoelectricity, Muscular Contraction