The widespread application of flexible electronic devices places higher demands for stretchable conductors as crucial components owing to their stable and consistently high conductivity and high stretchability. In this study, a superelastic conductive fractal helix fiber (FHF) consisting of a thermoplastic polyurethane fiber and Ag wire is developed, which exhibits excellent waterproofing ability. The maximum strain of the FHF can be improved to 8300% by increasing the helical index C and Ag wire winding density. A high conductivity of 6.3 × 107 S m−1 and ultra‐high Q value of 3.37 × 104 at a strain of 5600% are realized for the conductive fiber owing to its fractal helical structure. The elastic limit point A of the FHF can be obtained by the relative resistance change (0.166%) to ensure that elastic deformation only occurs when stress is applied. In the elastic strain range, FHF demonstrates high electrical reliability under repeated deformation (over 10 000 cycles of stretching with a strain of 5600%) with a negligible increase in resistance. Moreover, the FHF can be easily integrated with the fabrics as an interconnection for wearable electronics. The newly developed twined FHF can also be used as a capacitive strain sensor to monitor human activity.

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The significant potential of flexible sensors in various fields such as human health, soft robotics, human–machine interaction, and electronic skin has garnered considerable attention. Capacitive pressure sensor is popular given their mechanical flexibility, high sensitivity, and signal stability. Enhancing the performance of capacitive sensors can be achieved through the utilization of gradient structures and high dielectric constant media. This study introduced a novel dielectric layer, employing the BaTiO3-PDMS material with a gradient micro-cones architecture (GMCA). The capacitive sensor was constructed by incorporating a dielectric layer GMCA, which was fabricated using laser engraved acrylic (PMMA) molds and flexible copper-foil/polyimide-tape electrodes. To examine its functionality, the prepared sensor was subjected to a pressure range of 0–50 KPa. Consequently, this sensor exhibited a remarkable sensitivity of up to 1.69 KPa−1 within the pressure range of 0–50 KPa, while maintaining high pressure-resolution across the entire pressure spectrum. Additionally, the pressure sensor demonstrated a rapid response time of 50 ms, low hysteresis of 0.81%, recovery time of 160 ms, and excellent cycling stability over 1000 cycles. The findings indicated that the GMCA pressure sensor, which utilized a gradient structure and BaTiO3-PDMS material, exhibited notable sensitivity and a broad linear pressure range. These results underscore the adaptability and viability of this technology, thereby facilitating enhanced flexibility in pressure sensors and fostering advancements in laser manufacturing and flexible devices for a wider array of potential applications.