Flexible iontronic pressure sensing technology: advanced structural ionic layer

Since the advent of iontronic sensing technology, this emerging field has garnered growing research attention. Its unique electric double layer (EDL) theory reveals the characteristics of the ion-electron contact interface and can significantly increase the charge density per unit area, empowering the derived pressure sensors to achieve remarkable breakthroughs in sensitivity and detection accuracy. With an increase of several orders of magnitude in force-electric response compared with traditional capacitive pressure sensors, it provides core technical support for high-performance flexible sensing applications. Studies have shown that the contact area between the ionic layer and electrodes A decisively affects relative EDL capacitance, while designing and integrating different structural ionic layers directly enhances sensing performance. Focusing on the structural features, fabrication processes, and application scenarios of different types of structural ionic layers, this review comprehensively summarizes the advances in structural ionic layer design for flexible iontronic pressure sensing technology. By systematically evaluating the function-driven strengths and limitations of various structures, this review helps readers grasp the significance and objectives of ionic layer structures. Finally, based on advanced research, it provides an outlook on the field’s development trends and explores key potential challenges.