Capacitance tactile sensors (TSs) based on electrode distance and contact area variations have been notably employed for various purposes due to their magnificent stress sensitivity. Nevertheless, developing TSs with tunable responsiveness in a broad pressure interval is crucial owing to the trade-off between sensitivity and linear identification range. Herein, a TS including Ag-coated Velcro and spacer fabric is constructed, where its sandwich framework provides a sizable expansion in compression deformation ability. In addition, a multilayered framework composed of the stacked TS from self-adhesive Velcro provides more contact area and significant deformation for stress distribution, further balancing the sensitivity, sensing range, and linearity for smart garment application. By utilizing the overlaid selection of multilayer structures, the all-textile TS demonstrates outstanding sensitivity with a one-layer structure (0.036 kPa–1) over a pressure range of 0.2–5 kPa and retains a sensitivity of 0.002 kPa–1 in a four-layer structure over a wide pressure range of 0.2–110 kPa, representing a significant improvement compared to previous results. The sensor possesses excellent performance in terms of response speed (104 ms), repeatability (10,000 cycles), and flexibility. In addition, its significant applications, involving human motion detection, pliable keyboards, and human–computer interface, are successfully shown. Based on the facile and scalable manufacturing approach, a suitable procedure is presented to construct next-generation wearable electronics.

Yarn structure variation and property improvement have been widely investigated for applications in fancy fabric production. Thus, a novel composite yarn was fabricated by dynamically forcing strand migrations around filaments with varied tension control, regulating the geometric configuration between the filaments and staple fibers. The geometrical principle of wavy-network structure variations of novel composite yarns caused by tension interference and helical migrations between filaments and staple fibers was theoretically analyzed. Subsequently, the coordination of delivery speed ratios and untwisting factors was applied on a ring frame with a delivery roller to control the tensile difference and spiral trajectory, which oscillated the helical convergence between filaments and strands to conduct confirmatory tests. The online observations of the convergent formation in the spinning-triangle zone were technically applied to evaluate the dynamic helical migrations between strands and filaments, and the spiral structural variations of the yarn were caused by various tension difference interference and twist tracks. Experimental results revealed that the novel composite yarn had a network structure with wavy-dense wrapping, and the yarn hairiness, irregularity, tensile, and snarling properties were successively measured to compare the yarn property improvements with other composite yarns. Generally, the systematic tensile oscillation between strands and filaments in the yarn formation zone, which are produced by various delivery speed ratios and untwisting factors, are promising as a novel method for controlling the helical configurations and inter-stress between filaments and staple strands.

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The dynamic regulation of fiber stress distribution in the yarn-forming triangle area is critical for controlling variable composite yarn structures, including siro and sirofil composite yarns. In this study, comparison analyses of the variable geometric structure and stress distribution during the yarn-forming process, which involves step rolls with asymmetrical fiber control, have been carried out using ring-spinning technology. The geometric analyses show that partly staple fibers are continuously controlled while other fibers intermittently lack stress restraint, resulting in cyclically changed helical angles and wrapping density in the yarn-forming triangle area. The yarn structure model displayed that periodically distributed staple fibers occur in siro composite yarn, while sirofil composite yarn shows gradual periodic changes with uniform thickness variations, caused by cyclical changes in the stress distribution between filaments, and the strand altered the yarn-forming zone shapes from symmetrical to offset. Then, a systematic comparison of variable composite yarns with different frequencies (high, medium and low frequency) revealed that low-frequency step roll with wider grooves resulted in an intermittent output of staple fibers with less stress restraint, resulting in more pronounced structural variation in the siro and sirofil composite yarns with a slight yarn quality deterioration.

Control of tension distribution in the spinning triangle region that can facilitate fiber motion and transfer is highly desirable for high quality yarn production. Here, the key mechanisms and a mechanical model of gradient regulation of fiber tension and motion with rotary heterogeneous contact surfaces were theoretically analyzed. The linear velocity gradient, effected on a fiber strand using rotary heterogeneous contact surfaces, could balance and stabilize the structure and stress distribution of spinning triangle area, which could capture exposed fiber to reduce hairiness formation and enhance the internal and external fiber transfer to strengthen the fiber utilization rate. Then, varied yarns spun without and with the rotary grooved and rotary heterogeneous contact surfaces were tested to compare the property improvement for verifying above-mentioned theory. The hairiness, irregularity, and tensity of the yarns spun with rotary heterogeneous contact surfaces spun yarns were significantly improved compared to other spun yarns, which effectively corresponded well to the theoretical analysis. Based on this spinning method, this effective, low energy-consuming, easy spinning apparatus can be used with varied fiber materials for high-quality yarn production.