Advances in Piezoelectric Technologies for Vital Sign Monitoring Device

The rapid convergence of wearable electronics with the Internet of Things and artificial intelligence is driving the development of intelligent, self-powered systems for real-time monitoring of human health. Piezoelectric technologies offer promising solutions for continuous and non-invasive vital sign monitoring by enabling direct conversion of biomechanical signals into electrical outputs. This review summarises recent advances in piezoelectric materials, fabrication techniques, and biomedical applications for monitoring heart rate, blood pressure, and respiratory rate. The fundamentals of the piezoelectric effect are briefly introduced, followed by a classification of piezoelectric materials into single crystals, ceramics, polymers, and composites, with emphasis on their piezoelectric performance, mechanical properties, stability, biocompatibility, and toxicity. Progress in the fabrication technique of piezoelectric materials is presented. The integration of piezoelectric materials into biomedical systems is discussed alongside key challenges such as material sensitivity, long-term stability, mechanical flexibility, biocompatibility, toxicity, and system-level integration. Ultimately, future perspectives highlight emerging trends in material innovation, device-level integration, and system-level intelligence enabling personalised and continuous health monitoring. • Overview of fundamentals of piezoelectricity in biomedical application. • Materials in piezoelectric harvesters in health monitoring. • The applications of piezoelectric harvester in vital sign monitoring.