Design and experimental validation of a stress- controlled pressure sensor for wearable pulse monitoring

Abstract

This paper presents a pulse sensor design scheme with adjustable preset pressure. The design consist of two PVDF layers sandwiching a PZT layer. While PZT is used to detect the pulse vibrations, PVDF layers are employed to adjust the pressure load on PZT. This enables more reliable and repeatable pulse wave measurements every time the sensor is worn on the skin. A basic design and an I-shaped design are simulated on COMSOL software under Piezoelectric Device module to show maximum performance that can be achieved under same pressure conditions. Off-the-shelf components were used for testing the sensor designs under the same externally applied load. The I-shaped design was shown to outperform the basic sensor design in both simulations and test results. This design can be employed in the development of reliable and repeatable pulse sensors, and poses significant potential in measuring the blood pressure.