Thermally Activated Mechanoluminescence for Dynamic Multimodal Encryption and Intelligent Handwritten Digit...

Next-generation human-machine interfaces and unclonable security systems demand materials that can convert a gentle touch into a bright, readable optical signal. Here, we realize this vision by fabricating a smart interactive terminal that recognizes handwritten digits with 99.35% accuracy and a dynamic anticounterfeiting platform that displays distinct, encrypted information under either optical or mechanical stimuli. The foundation of these breakthroughs is a simple yet powerful thermal activation (TA) strategy we developed for low-cost commercial ZnS/Cu phosphors. This treatment unlocks a five-time increase in mechanoluminescent (ML) brightness, extends afterglow persistence from 30 s to over 20 min, and drastically reduces the activation stress from 2.0 N to a gentle 0.5 N. Mechanistic studies reveal that these dramatic improvements stem from the activation of intrinsic sulfur vacancies within the material. This work not only demonstrates the seamless integration of high-performance ML materials into sophisticated mechano-optoelectronic systems but also provides a strategic reference for transforming commercial materials into key components for future intelligent interactive technologies.