In-situ synthesis of iontronic flexible PDMS foam pressure sensors for high-sensitive and wide-range wearable monitoring

Abstract Flexible iontronic pressure sensors utilizing polydimethylsiloxane (PDMS) microarchitectural design are capable of delivering high sensitivity along with an extended detection range. However, the inherent incompatibility between PDMS and ionic media tends to cause ion leakage and performance degradation. A porous iontronic pressure sensor (PIPS) based on PDMS foam is presented. By employing an in-situ composite process, an ionic liquid (IL)/PVDF gel electrolyte is incorporated into the three-dimensional porous network of PDMS, forming a robust cross-linked structure within the pore channels. This approach achieves complete encapsulation and immobilization of the IL at the microscale, which effectively mitigates ion leakage and ensures the long-term reliability of the device. The fabricated PIPS exhibits a high sensitivity of 2.62 kPa −1 within the 3–110 kPa range and 0.91 kPa −1 from 110–500 kPa, effectively integrating excellent sensitivity with an extended detection range. Additionally, it shows a low detection threshold of 10 Pa, a rapid response time of 51 ms, and stable performance over more than 3000 operational cycles. Leveraging these advantages in sensitivity and stability, the PIPS has been successfully applied in human physiological signal monitoring, flexible sensing arrays, and wireless passive sensing. This study proposes an innovative method for manufacturing high-performance and highly reliable flexible pressure sensors, showing significant potential for applications in advanced sensing technologies.