Ultrasensitive multi-degree-of-freedom piezoionic sensor via synergistic hydrogel-ion interactions.
biomechanical · Level V
Where this comes from
- Record sourced from PubMed, PMID 41444483.
- Also identified by DOI 10.1038/s41467-025-67613-8 and PMC identifier 12830910.
- Licence recorded as CC BY-NC-ND.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Accurate body motion capture is of great significance for biomechanical assessment and immersive virtual/augmented reality (VR/AR) systems. Piezoionic flex-sensors, which mimic the ionic transport sensing mechanism of cutaneous mechanoreceptors, promises a self-powered approach for wearable body movements detection. However, their practical utility has been limited by low piezoionic flex-sensitivity (typically below 0.5 mV/degree) and unidirectional bending response, which restricts their ability to resolve complex multi-degree-of-freedom (multi-Dof) body motions. Here we report a soft, piezoionic and multi-Dof (SPIM) flex-sensor that overcomes these limitations. It ingeniously integrates zwitterionic dipole-ion interactions and size-induced steric hindrance effects to enable fast ion channels formation and amplified cation/anion transport imbalance, thus cooperatively contributing to a record-high piezoionic flex-sensitivity of 3.2 mV/degree. Theoretical simulations combining poroelastic mechanics and Poisson-Nernst-Planck model corroborated the synergistic enhancement. Furthermore, a unique architecture of square prism-shaped fiber with two pairs of symmetric nanomesh electrodes allows the SPIM flex-sensor to decouple multi-Dof joint flexion to distinguish complex body movements. We demonstrate a SPIM flex-sensor platform for metaverse applications, including a digital-twin of free-pose hand motions and complex yet intuitive VR control via single-joint dexterity equipped with a single compact sensor device.