All-In-One Iontronic Sensing Aligner for High-Precision 3D Orthodontic Force Monitoring

Clear aligners offer aesthetic and comfort advantages in orthodontics, yet their ability to deliver effective forces relies heavily on empirical judgment or large-scale optical scanning, lacking real-time quantitative evaluation. Integrating pressure sensors into aligners is a promising solution, but challenges in miniaturization, multi-dimensional sensing, measurement accuracy, and biocompatibility hinder clinical application. Here, an all-in-one Orthodontic Force Acquisition System (OFAS) is presented that enables real-time, 3D force monitoring using a cross-shaped iontronic sensing array and an origami-inspired, wireless battery-free readout circuit miniaturized for single-tooth placement. The system employs a cross-linked polyelectrolyte with low creep and high repeatability, achieving 1.14% measurement accuracy. A 15-day in vivo study demonstrates that OFAS accurately captured dynamic force profiles with strong correlation to tooth displacement (R 2 > 0.99), confirming its feasibility for real-time, quantitative orthodontic force measurement and enabling timely treatment adjustments.