Microstructured PVDF-HFP/TPU Ionogels for Wide-Range Iontronic Pressure Sensing

Iontronic pressure sensors (IPSs) are attractive for flexible interfaces because electric-double-layer (EDL) capacitance enables high signal output from interfacial deformation, yet it remains challenging to simultaneously achieve high sensitivity, a wide pressure range, and stable operation under temperature variation. Here, we report a microstructured PVDF-HFP/TPU/[EMIM][TFSI] ionogel dielectric for robust iontronic pressure sensing. The ionogel is fabricated by a scalable solution-casting process, in which solvent-evaporation-induced phase separation generates an interconnected porous microstructure without templating. This microstructure increases dielectric compressibility and promotes pressure-dependent ion redistribution at the electrode/ionogel interface, leading to a sensitivity of 13.9 nF kPa^-1 below 40 kPa and a measurable response up to 5 MPa. To improve signal reliability, a precalibrated thermal-coefficient compensation method is introduced to suppress capacitance drift over 30-70 °C. Integrated into multichannel sensor arrays, the device further enables proof-of-concept classification of representative seated postures and simulated cabin interaction patterns under controlled laboratory conditions, combined with machine-learning analysis. This work demonstrates a scalable ionogel dielectric platform for robust pressure sensing and highlights its potential for contact-based cabin-state monitoring.