Interphase‐Induced Flexible Piezoelectric Sensing for Intelligent Decoding of Cardiac Disorders

ABSTRACT Long‐term monitoring and early diagnosis of cardiovascular diseases are crucial to reducing morbidity and mortality. Given the challenges of electrocardiogram monitoring due to stringent environmental requirements and high costs, leveraging wearable pulse signals for cardiovascular disease detection becomes a key solution. Here, we introduce an interphase‐induced stress modulation mechanism to fabricate a high‐performance flexible piezoelectric ceramic sensor via a one‐step mechanical thinning strategy, which exhibits a high longitudinal piezoelectric coefficient of 280 pC/N, and an outstanding thickness‐to‐diameter ratio of ∼0.01. Theoretical analysis and experiments show that the metal interphase between the brittle ceramic and hyperelastic substrate creates a stress gradient, enabling large, reversible bending. Furthermore, we developed a wireless piezoelectric sensing system based on the double‐feature temporal convolutional network (DTCN) to detect common cardiac diseases from piezoelectric pulse signals. This approach enables continuous pulse monitoring for early prevention and long‐term monitoring of pacemaker patients.