The Polymer Society of Korea

Abstract

Fiber sensors with engineered architecture offer a compelling platform for next-generation wearable electronics, owing to their inherent mechanical adaptability and compatibility with textile integration. In this study, a multimodal fiber sensor with a one-dimensional double-helix architecture is introduced, enabling the independent detection of pressure and strain stimuli within a single device. Strain sensing is realized via piezoresistive changes in a helical conductive fiber, while pressure is detected through piezocapacitive responses between two twisted fiber electrodes separated by a dielectric layer. This structural configuration ensures effective decoupling of signals, yielding reliable dual-mode operation without cross-interference. The strain-sensing component demonstrates a gauge factor of 0.03 ± 0.001 %⁻¹, high linearity (0.996–0.999), negligible hysteresis, and rapid response (~ 300 ms) and recovery (~350 ms) times over an extended strain range (0–300 %). The pressure sensor exhibits a gauge factor of 0.001 ± 2 × 10⁻⁵ kPa⁻¹, excellent linearity (0.992), fast response (~150 ms), and mechanical durability over 2500 cycles. Practical demonstrations—including joint motion, respiration, tactile force, and airflow detection—validate the sensor’s multimodal functionality. By integrating high fidelity, minimal signal interference, and robust structural performance, the proposed double-helix fiber sensor presents a versatile and scalable solution for wearable multimodal sensing applications.