This article introduces a novel micro-flexure-sensitive fiber electronics system, called NB-fiber, which enhances the sensitivity and robustness of triboelectric fibers for monitoring subtle physiological signals. The NB-fiber is designed based on a dynamic stability model of sheath-core fibers, integrating a micro-flexure-sensitive fiber enabled by nanofiber buckling and an ion conduction mechanism. This system achieves a detectable signal at an ultra-low curvature of 0.1 mm⁻¹ and a flexure factor of >21.8% within a bending range of 10°. The NB-fiber is also scalable and compatible with modern weaving techniques, enabling its use in various physiological diagnoses, particularly in monitoring upper limb muscle strength for rehabilitation and training. The NB-fiber is inspired by the Meissner corpuscle, which is a low-threshold mechanoreceptor in biological systems. The NB-fiber is constructed by implementing an ordered distribution of nanofiber buckling at the ionic conductive interface. This design allows for high-specific surface tribo-interfaces, which enhance the sensitivity and robustness of the fiber. The NB-fiber is manufactured using a continuous process involving pre-stretching, electrostatic field pulling, and in-situ annealing. The resulting NB-fiber exhibits high flexibility, sensitivity, and durability, making it suitable for applications in biomechanical feedback systems. The NB-fiber demonstrates exceptional performance in detecting and measuring flexure deformations, with a high sensitivity and robustness. It is capable of detecting subtle physiological signals such as pulse, respiration, and muscle exertion. The NB-fiber is also applicable in the development of NB-textile, which is a flexible and stretchable textile that can be used for biomechanical feedback. The NB-textile is compatible with standard textile techniques and can be used for a wide range of applications, including rehabilitation training and health diagnosis. The NB-fiber and NB-textile have significant potential in the field of wearable electronics and biomedical applications. They offer a promising solution for monitoring physiological signals with high accuracy and sensitivity. The NB-fiber's ability to detect micro-curvature makes it a valuable tool for developing advanced prosthetics and exoskeletons. Overall, the NB-fiber and NB-textile represent a significant advancement in the field of fiber electronics, with the potential to revolutionize the way we approach healthcare and wellness.This article introduces a novel micro-flexure-sensitive fiber electronics system, called NB-fiber, which enhances the sensitivity and robustness of triboelectric fibers for monitoring subtle physiological signals. The NB-fiber is designed based on a dynamic stability model of sheath-core fibers, integrating a micro-flexure-sensitive fiber enabled by nanofiber buckling and an ion conduction mechanism. This system achieves a detectable signal at an ultra-low curvature of 0.1 mm⁻¹ and a flexure factor of >21.8% within a bending range of 10°. The NB-fiber is also scalable and compatible with modern weaving techniques, enabling its use in various physiological diagnoses, particularly in monitoring upper limb muscle strength for rehabilitation and training. The NB-fiber is inspired by the Meissner corpuscle, which is a low-threshold mechanoreceptor in biological systems. The NB-fiber is constructed by implementing an ordered distribution of nanofiber buckling at the ionic conductive interface. This design allows for high-specific surface tribo-interfaces, which enhance the sensitivity and robustness of the fiber. The NB-fiber is manufactured using a continuous process involving pre-stretching, electrostatic field pulling, and in-situ annealing. The resulting NB-fiber exhibits high flexibility, sensitivity, and durability, making it suitable for applications in biomechanical feedback systems. The NB-fiber demonstrates exceptional performance in detecting and measuring flexure deformations, with a high sensitivity and robustness. It is capable of detecting subtle physiological signals such as pulse, respiration, and muscle exertion. The NB-fiber is also applicable in the development of NB-textile, which is a flexible and stretchable textile that can be used for biomechanical feedback. The NB-textile is compatible with standard textile techniques and can be used for a wide range of applications, including rehabilitation training and health diagnosis. The NB-fiber and NB-textile have significant potential in the field of wearable electronics and biomedical applications. They offer a promising solution for monitoring physiological signals with high accuracy and sensitivity. The NB-fiber's ability to detect micro-curvature makes it a valuable tool for developing advanced prosthetics and exoskeletons. Overall, the NB-fiber and NB-textile represent a significant advancement in the field of fiber electronics, with the potential to revolutionize the way we approach healthcare and wellness.