Sugar-plastic assisted fabrication of hollow PDMS wearable fabrics toward excellent sensory capabilities

Abstract

Fiber-based pressure sensors have gained widespread attention because of their highly flexible, breathable and biocompatible potential applications for motion detection, human–machine interfaces, intelligent healthcare, and so on. However, the restricted deformation space and inherent inelasticity of the fibers limit their pressure-sensing, especially the pressure-sensing range. Thus, the fabrication of high-performance fiber-based pressure sensors remains challenging. Inspired by traditional sugar-plastic technology, we report that a soft hollow polydimethylsiloxane (PDMS) fiber with embedded carbon nanotubes (CNTs) was prepared via a convenient and efficient sugar-plastic approach. Intriguingly, the soft hollow PDMS/CNT fiber is further coated with rigid conductive polydopamine–polypyrrole, which is developed as a finger-like hierarchical structure. The resulting hollow fiber exhibits lightweight (a low density of ∼0.47 g cm⁻³) and good mechanical properties (tensile strength of ∼6.2 MPa and elongation at break of ∼203%). Besides, the hollow fibers are assembled into a pressure sensor that offers excellent sensing performance for a wide range of pressures up to ∼725 kPa, and tactile recognition ability based on different surface roughnesses. Our sensor coupled with machine learning creates an intelligent tactile recognition system, enabling 97.4% object recognition accuracy. Such a straightforward and efficient building strategy combined with the unique structure may help design advanced wearable electronic devices for intelligent applications.