Stretchable One-Dimensional Conductors for Wearable Applications

Abstract

Continuous, one-dimensional (1D) stretchable conductors have attracted significant attention for the development of wearables and soft-matter electronics. Through the use of advanced spinning, printing, and textile technologies, 1D stretchable conductors in the forms of fibers, wires, and yarns can be designed and engineered to meet the demanding requirements for different wearable applications. Several crucial parameters, such as microarchitecture, conductivity, stretchability, and scalability, play essential roles in designing and developing wearable devices and intelligent textiles. Methodologies and fabrication processes have successfully realized 1D conductors that are highly conductive, strong, lightweight, stretchable, and conformable and can be readily integrated with common fabrics and soft matter. This review summarizes the latest advances in continuous, 1D stretchable conductors and emphasizes recent developments in materials, methodologies, fabrication processes, and strategies geared toward applications in electrical interconnects, mechanical sensors, actuators, and heaters. This review classifies 1D conductors into three categories on the basis of their electrical responses: (1) rigid 1D conductors, (2) piezoresistive 1D conductors, and (3) resistance-stable 1D conductors. This review also evaluates the present challenges in these areas and presents perspectives for improving the performance of stretchable 1D conductors for wearable textile and flexible electronic applications.

Hygroscopic MXene/Protein Nanocomposite Fibers Enabling Highly Stretchable, Antifreezing, Repairable, and Degradable Skin-Like Wearable Electronics

“…With the gradual increase of interdisciplinary convergence and technological convergence, many new areas of development have emerged, such as implantable medical devices, soft robots, wearable devices, electronic fabrics, etc. − Particularly, the rise of personalized healthcare has spurred the development of flexible wearable and implantable electronic devices for monitoring physiological signals. Compared to conventional 3D and 2D electronic devices, fiber-based electronic devices have the advantages of high aspect ratio, lightweight, high flexibility, and weavability. − When applied to the skin, it can achieve a high degree of adaptability to the skin, thereby improving the comfort of the human body and enhancing signal fidelity during motion. , In health monitoring, fiber-based flexible sensors can monitor large-scale (such as the fingers, arms, and legs) and small-scale (such as emotional expression of face, breathing, and swallowing) human body movements to diagnose vocal cord damage, respiratory disorders, angina pectoris, etc. , Typically, the reported fiber-based sensors use stretchable elastomers, such as polydimethylsiloxane (PDMS), Ecoflex, and polyurethane (PU), as substrates with the conductive materials coated on the surface or embedded in the matrix to realize a close fit with the human body. − For instance, Seyedin et al prepared a fiber-based wearable strain sensor with Ti 3 C 2 T x MXene embedded in PU by wet spinning, which exhibited high sensitivity and could be used to monitor elbow joint movement. However, these polymers display poor air permeability and biocompatibility, which will cause skin discomfort during long-term usage.…”

Highly Stretchable and Fluorescent Visualizable Thermoplastic Polyurethane/Tetraphenylethylene Plied Yarn Strain Sensor with Heterogeneous and Cracked Structure for Human Health Monitoring

“…To develop yarn strain sensors, various flexible polymers such as polydimethylsiloxane (PDMS), silicone rubber, and thermoplastic polyurethane (TPU) have been used as stretchable substrates, while materials like carbon nanotubes (CNTs), silver nanowires, Au, MXene, and conductive polymers have been employed as conductive materials. − Research indicates that traditional strain sensors with a constant diameter exhibit limited sensitivity due to a uniform stress distribution. In order to enhance the sensitivity of the sensor, the sensor can obtain different stress distributions under a certain strain through a structural design.…”

Hierarchical Fermat helix-structured electrochemical sensing fibers enable sweat capture and multi-biomarker monitoring

“…[1][2][3][4] The non-invasive detection of sweat at the molecular level using wearable electrochemical sensors for health monitoring and disease prevention has been extensively researched in recent years. [5][6][7] Glucose, lactic acid, and many other redox-active molecules (e.g., dopamine, uric acid) present in sweat can be detected using the amperometric method. Besides, various ions (Na + , K + , Ca 2+ , etc.)…”