Human motion monitoring in sports using wearable graphene-coated fiber sensors

• Published in: Sensors and actuators. A. Physical. 2018-05, Vol.274, p.132-140
• Main Authors: Zhang, Jinnan, Cao, Yanghua, Qiao, Min, Ai, Lingmei, Sun, Kaize, Mi, Qing, Zang, Siyao, Zuo, Yong, Yuan, Xueguang, Wang, Qi
• Format: Article
• Language: English
• Subjects: Athletes; Coated fibers; Fibers; Graphene; Graphene-coated fiber; Graphite; Human motion; Monitoring; Monitoring systems; Movement; Reproducibility; Sensitivity; Sensors; Soccer; Sports; Wearable computers; Wearable sensor; Wearable technology
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2018.03.011

•We have fabricated a wearable graphene-coated fiber sensor at an inexpensive cost and a simple process. Double-covered yarn (DCY) is used as the elastic scaffold, which consisted of a highly elastic polyurethane (PU) core fiber and polyester (PE) fibers winding around the PU core helically. After treatment of air plasma etching and dip-coating, the graphene-coated fiber sensor is fabricated. The PDCY-RGO fiber is light (only about 0.28 g/m) and flexible enough to conform to any position of the human body, including those of the throat, finger, knee, and so on. So, the sensor is suitable for monitoring the movement of the human body.•The graphene-coated fiber not only has multiple functions in terms of stretching, bending, and torsion but also shows excellent performance in terms of a combination of high sensitivity, a broad sensing range and a high reproducibility. The fiber sensor maintains stable and accurate performance under both low and high strains in stretching testing, bending testing and torsion testing. These features allow its application as a full-range human motion and activity sensor. The results clearly show that the sensor has potential for practical applications in human motion detection.•We attach the wearable fiber sensors to elbow and wrist to monitor the basic movements of the human body. Firstly, we test elbow flexion and extension. All the changes in and maintenance of the basic motions can be observed. Even an overshoot can be observed at the instant of the action switch. Bending and rotation movements of wrist are also tested. Although the wrist’s motion range is far less than that of the elbow, relative resistance changes are still obvious and corresponded to the motion. By processing and analyzing the raw data, all motions can be identified and analyzed.•We capture the typical action of soccer and basketball. Applying the fiber sensor to the joints of the human body, including the shoulder, elbow, wrist, knee, and ankle, we achieve the accurate monitoring of the motions of athletes. The movements of different shots and kicks are monitored. Furthermore, based on the raw data obtained from the sensors in various positions, the motion types can be accurately identified, and the athlete’s motions can be improved too. We also achieve accurate monitoring and identification of the nuances shown in the same joint movement by different athletes. Human motion monitoring is significant for professional athletes who desire to improve their