Sensor iónico de hidrogel de Hofmeister para monitorización de movimiento en modo dual

Flexible pressure sensors hold great promise for applications in motion monitoring and human signal recognition. However, conventional devices with fixed structure-performance coupling often fail to meet the diverse demands of different body sites and multi-scenario monitoring. Herein, we propose a polyvinyl alcohol (PVA)-hydroxyethane diphosphonic acid (HEDP) hydrogel iontronic sensor (PHHIS) with modulus programmability regulated by the Hofmeister effect. By introducing weakly hydrated I^- and strongly hydrated SO₄^2-, we constructed soft-mode and hard-mode PHHIS, enabling precise acquisition of both low- and high-pressure human signals. The soft mode achieves ultrahigh sensitivity (238.4 kPa^-1, 0-50 kPa), ideal for subtle signals such as pulse and vocalization, while the hard mode maintains stable linearity (1.5 kPa^-1, 0-800 kPa), suitable for limb movement monitoring. Eight classes of human signals were precisely recognized with 100% accuracy through feature extraction combined with linear discriminant analysis, hierarchical cluster analysis, and artificial neural network analysis. This work demonstrates the promise of Hofmeister effect-regulated hydrogel design for programmable modulus control, enabling high-performance signal recognition and advancing flexible iontronic sensors for intelligent health monitoring.