Inkjet‐printed iontronics for transparent, elastic, and strain‐insensitive touch sensing matrix

Abstract

Next‐generation soft electronics are expected to be intrinsically stretchable, skin conformable, and fully integrated with diverse receptive modules to facilitate bidirectional human–machine interactions. Receptive touch sensors, in particular, should provide stable touch sensing outputs without being affected by external force‐induced strains. Herein, the design and fabrication of an iontronic touch sensing matrix, based on the fringe‐field capacitive mechanism, are introduced for robust touch mapping under large deformation. Enabled by our well‐formulated ink, ionic gel electrodes are directly inkjet printed onto elastomeric substrate to impart superior transparency and elasticity, and hybridized with a customized electronic circuitry through electrical double layers (EDLs) for the multiplexing and transduction of capacitive signals. Notably, the coplanar “interlocking‐diamond” electrode layout in a stretchable modality is adopted for the first time, which helps to boost touch sensitivity and suppress strain‐induced artifacts under static/dynamic deformations. For practical applications, the iontronic matrix demonstrates the capabilities of proximity sensing, multitouch detection, and gesture communication in real time, leading to a robust touch sensing interface that captures high‐fidelity signals during complex human–machine interactions.