Bioelectrical or electrophysiological signals generated by living cells or tissues during daily physiological activities are closely related to the state of the body and organ functions, and therefore are widely used in clinical diagnosis, health monitoring, intelligent control and human-computer interaction. Ag/AgCl electrodes with wet conductive gels are widely used to pick up these bioelectrical signals using electrodes and record them in the form of electroencephalograms, electrocardiograms, electromyography, electrooculograms, etc. However, the inconvenience, instability and infection problems resulting from the use of gel with Ag/AgCl wet electrodes can’t meet the needs of long-term signal acquisition, especially in wearable applications. Hence, focus has shifted toward the study of dry electrodes that can work without gels or adhesives. In this paper, a retrospective overview of the development of dry electrodes used for monitoring bioelectrical signals is provided, including the sensing principles, material selection, device preparation, and measurement performance. In addition, the challenges regarding the limitations of materials, fabrication technologies and wearable performance of dry electrodes are discussed. Finally, the development obstacles and application advantages of different dry electrodes are analyzed to make a comparison and reveal research directions for future studies.

Smart textiles, which integrate different electronic devices in yarns, fabrics, or garments, have the ability to perceive and respond to environmental stimuli. With the features of mechanical flexibility, knittable integration, and wearable comfort, smart textiles have great potential in wearable electronics. Here, a naturally integrated force sensing textile based on knittable composite coaxial fibers is proposed. A flexible commercial nylon fiber works as a substrate, an evaporated Au layer serves as an inner electrode, and carbon nanotubes and polyaniline act as piezoresistive sensing materials in the coaxial fibers. The assembled sensor retains both high detection performance and outstanding integration properties. A high detection limit, fast response, reversible recovery, mechanical stability, and good repeatability are realized in this sensor. Subsequently, the potential of using a coaxial fiber to achieve naturally knitted structures by an embroidery method is explored. A sensing array can be integrated into designed patterns and can achieve multiple site force measurements. Furthermore, with the flexibility and porosity of textiles, these smart textiles provide breathability in wearable applications, which is valuable in long‐term detection. It is anticipated that the naturally knitted smart textile will be practical in wearable healthcare and long‐term force perception.

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