Axially decoupled multidirectional stretchable strain sensor based on plain-woven carbon nanotube-infiltrated rubber nanocomposites

Accurately sensing the direction and magnitude of strain is essential for decoding complex mechanical deformations, particularly in human-centered wearable technologies. However, conventional technologies based on orthogonally arranged strain sensors fixed on soft substrates inevitably suffer from mechano-electrical coupling between sensing axes, which complicates signal interpretation. In this study, we developed a plain-woven strain sensor composed of piezoresistive rubber nanocomposite strips that achieves exceptionally low axial crosstalk while maintaining high sensitivity and stretchability. The orthogonally interlaced structure enabled mechanical decoupling between sensing axes, resulting in an on-to-off-axis sensitivity ratio of 1446.8. The nanocomposite forming the woven sensing architecture was prepared by infiltrating a swollen rubber matrix with multiwalled carbon nanotubes, resulting in a percolation network beneath the rubber surface while preserving the inherent mechanical properties of natural rubber, including its low elastic modulus and high stretchability. As a result, plain-woven nanocomposite bands exhibited gauge factors of 3.9, 13.4, and 30.5 in the strain ranges of 0–150%, 150–300%, and 300–500%, respectively, with stable cycling performance. The utility of the multidirectional strain sensor was evaluated through glove-based finger gesture recognition and sleeve-based knee joint monitoring. The sensor exhibited accurate decoupling of the strain magnitude and direction, demonstrating its suitability for next-generation wearable biomechanical feedback systems.