Ultra‐Sensitive and Broad‐Range Iontronic Pressure Sensor Based on ZnO‐Reinforced Sodium Alginate With CaCl2

Abstract Flexible pressure sensors are unprecedentedly developed on monitoring human physical activities and human–computer interaction. Simultaneously, improving the sensitivity and pressure range of flexible pressure sensors is a great challenge. Despite the introduction of microstructures on the dielectric layer, the deformability is still limited due to the size constraints of the microstructures, and the sensitivity of iontronic capacitive pressure sensor (ICPS) is still difficult to significantly improve. Here, an innovative strategy of combining nano‐ZnO and sodium alginate (SA) ionogels with two‐stage enhancement (TSE) structures, which can significantly enhance the toughness and sensitivity of ICPS for ultrasensitive pressure range, is proposed. Compared with other previously reported pressure sensors, the sensor developed in this work exhibits an ultra‐high sensitivity (S max >17000 kPa −1 , S min >360 kPa −1 ) in a broad sensing range of more than 900 kPa and maintains stable long‐term working durability for 4000 cycles. The sensor demonstrates its versatility potential in practical applications in physical activity monitoring and human–computer interaction. This work provides a general strategy to achieve an ICPS with broader pressure‐response range and higher sensitivity, offering a stable and effective way for a low‐cost, scalable pressure sensor.