Forming Mechanism of Hydrogel Sensors Based on Hollow Fiber with Heteromorphic Lumen

Yu Li; Shengzhao Qiao

doi:10.62051/ijmsts.v5n2.08

Authors

Yu Li
Shengzhao Qiao

DOI:

https://doi.org/10.62051/ijmsts.v5n2.08

Keywords:

Hollow fiber, Special-shaped lumen, Flow rate change, Preparation and regulation, Flexible sensor

Abstract

Cross-linking reaction flow forming is an advanced technology for preparing hollow fiber hydrogels, featuring simple process, continuous meter-level preparation and 3D structure construction. However, hydrogel sensors made by this method have poor tunability in mechanical and electrical properties, limiting their application. To solve this, this study focuses on the design, preparation, performance testing of heteromorphic lumen hydrogel sensors and their application in flexible sensors. Firstly, an experimental platform for precise extrusion control was built using a coaxial nozzle and microinjection pump system. By adjusting the flow rate of inner-phase calcium chloride (with outer-phase sodium alginate), variable-diameter heteromorphic lumen hydrogels were precisely prepared. A theoretical model based on flow rate regulation was proposed to characterize lumen morphology changes, providing theoretical support for structural optimization. Subsequently, the effects of sodium alginate (3%–5%) and lithium chloride (3%–5%) concentrations on hydrogel properties were explored. Results show that higher sodium alginate concentration improves tensile strength, elongation at break and fatigue resistance, while electrical properties first rise then fall. Higher lithium chloride concentration reduces mechanical properties but enhances electrical conductivity (with significant strain-dependent changes). The optimal formulation (3.75% sodium alginate, 5% lithium chloride) achieves 65 kPa maximum stress and 33.86 S/m maximum conductivity. In summary, this study realized precise regulation and performance optimization of hydrogel sensors via heteromorphic lumen design. Flow rate adjustment and concentration optimization are crucial for improving their mechanical, electrical and sensing properties, providing theoretical and practical support for their application in high-precision biological signal monitoring and flexible electronics.

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