Imperceptible, designable, and scalable braided electronic cord

Abstract

Flexible sensors, friendly interfaces, and intelligent recognition are important in the research of novel human-computer interaction and the development of smart devices. However, major challenges are still encountered in designing user-centered smart devices with natural, convenient, and efficient interfaces. Inspired by the characteristics of textile-based flexible electronic sensors, in this article, we report a braided electronic cord with a low-cost, and automated fabrication to realize imperceptible, designable, and scalable user interfaces. The braided electronic cord is in a miniaturized form, which is suitable for being integrated with various occasions in life. To achieve high-precision interaction, a multi-feature fusion algorithm is designed to recognize gestures of different positions, different contact areas, and different movements performed on a single braided electronic cord. The recognized action results are fed back to varieties of interactive terminals, which show the diversity of cord forms and applications. Our braided electronic cord with the features of user friendliness, excellent durability and rich interaction mode will greatly promote the development of human-machine integration in the future.

Fig. 1. A braided electronic cord based on core-spun pressure-sensing yarns.

a Schematic illustration for the fabrication of a core-spun pressure-sensing yarn. b Photograph of a core-spun pressure-sensing yarn. c Schematic illustration for the cross-contact between the core-spun yarns. d Optical micrograph of a core-spun yarn cross-section. e Schematic illustration for the fabrication of a braided electronic cord. f Photograph of a braided electronic cord with a diameter of 2.5 mm. g Schematic illustration for the braiding structure. h Photograph of the automated fabrication of a braided electronic cord. i Schematic illustration for a sensing point and repeating braiding structure of a braided electronic cord.

Fig. 2. Characterization of braided electronic cord.

a The capacitance response of the braided electronic cord from a triple compress release cycles of compression under forces of 20 N, 30 N, and 50 N. b Relationship between relative change in capacitance and applied pressure of braided electronic cord. c Relationship between relative change in capacitance and applied contact area of the braided electronic cord. d Capacitance response of braided electronic cord repeated compress release over 10,000 cycles under a force of 35 N (i) and relative capacitance of braided electronic cord without pressure versus the number of repeated compress release cycles (ii).

Fig. 3. Cord-based human–computer interaction.

a Processing flow of human–computer interaction of the braided electronic cord. b Overview of our proposed algorithm to realize action recognition based on human–computer interaction application. c The confusion matrix of our proposed algorithm. d Evaluation results of action recognition based on our proposed algorithm and other machine learning-based classifiers. e Examples of a miniaturized platform by the braiding cord into hair with three pinches and grab to control music player App, such as switching songs and changing the volume.

Fig. 4. Intelligent interaction application scenario.

a Schematic illustration for the interaction system based on the braided electronic cord. b Photograph of a smart hand catenary. c Examples of a smart hand catenary for an emergency call with limited mobility. d Capacitance response for different interactive activities to the smart hand catenary. e Photograph of smart fabrics based on a knotted cord. f Examples of smart fabrics for musical instruments playing. g Capacitance response for different interactive activities to the strings. h The light can be controlled by pressing interactive embroidery pillow based on core-spun yarns. i Photograph of interactive embroidery pillow based on core-spun yarns. j Capacitance response of pressing at different letter embroidery.