Iontronic Capacitive Pressure Sensors With Enhanced Sensitivity Enabled by an Ionic Asymmetric Fiber Mat

ABSTRACT Flexible pressure sensors are pivotal for next‐generation applications in health monitoring, electronic skin, and human‐machine interaction. While iontronic sensors are prized for their high sensitivity, conventional methods to optimize the dielectric layer often involve complex and costly microfabrication. This work presents a high‐sensitivity iontronic sensor created from an ionic asymmetric fiber mat (i‐AFM) dielectric, fabricated by a simple sequential electrospinning process. This ionic‐asymmetric and fibrous design synergistically minimizes initial capacitance while maximizing the pressure‐induced interfacial contact area change. The resulting device achieves an ultra‐high sensitivity of 47.27 kPa −1 , a wide linear range up to 750 kPa, an ultra‐low detection limit of 0.86 Pa, and a fast response/recovery time of 1.92/7.06 ms. The sensor accurately monitors tiny pressures and various physiological signals, including pulse, breathing, swallowing vibration, and joint bending. Furthermore, a 4 × 4 sensor array enables spatial pressure mapping, and integration with a machine learning model achieves >95.00% accuracy in speech recognition. This versatile, high‐performance sensing platform holds significant promise for wearable healthcare, soft robotics, and human‐machine interaction.