Natural polymer based conductive hydrogel wireless wearable flexible sensor

In recent years, flexible wearable electronic devices rapid development, with potential applications in the field of motion monitoring, medical rehabilitation and software robots. stretchable conductive hydrogel with its flexibility and excellent detection sensitivity is considered to be one of the ideal choice of the flexible sensor. However, the conductive hydrogel sensors reported to date there is limited distortion detecting section, low sensitivity, insufficient mechanical properties of the problem, these problems seriously affected the further development of the conductive hydrogel of the sensor. Furthermore, the conventional flexible wearable sensor for detecting the detection device is limited to be bound, wireless sensor networks with the development of technology is expected to further facilitate the wearable electronic device with a flexible wearable sensors. Recently, East China Normal University, Professor Xu Min and Professor Pan Likun team Japan Institute for Materials Dr. Xu Xingtao natural polymer is alginate cooperation body, opposite to the introduction of electrically functional monomer (acrylic acid and acrylamide) and a metal ion salt (zinc sulfate), the successful synthesis of a high tensile, since the shape recovery, the conductive good natural zwitterionic conductive polymer hydrogel (FIG. 1).

Based on the three dimensional structure itself has a natural polymer, in situ polymerization of functional monomers incorporated in the network structure of the natural polymer, is formed with a large number hydrogel matrix oppositely charged functional groups, the zinc ions such that the presence of functional groups on the polymer chain closely together. By means of dynamic interactions in the hydrogel structure, natural polymer conductive hydrogel exhibits excellent mechanical properties, conditions of 0.21 MPa at 4200% stretching ratio of , while the presence of the dynamic interactions , also gives the unique shape of the conductive hydrogel self-healing properties, when the hydrogel is stretched to 4000%, yet quickly restitution within 20 minutes and has good cycle stability [123 ](figure 2).

Figure 2. The hydrogel mechanical properties of the conductive zwitterionic natural polymer. a: the tensile stress-strain curve; b: show flexibility; c-d: a schematic view of a high drag mechanism; e-f: conductiveSelf-healing hydrogel shape.Because of its flexibility and good conductivity, the conductive natural polymer hydrogels exhibit excellent electrical and mechanical properties, not only to monitor the body movements, the frequency of operation is also possible, velocity, amplitude and time span of feedback information, sensitivity, response time, the monitoring range and durability exhibited excellent performance (FIG. 3).

Figure 3. zwitterionic natural organic polymeric conductive hydrogel characteristics. a-c: stress strain monitoring; d-f: monitoring the movement of a finger, g: Response rate monitor; h: monitoring cycle stability.In order to further verify the timeliness wearable wireless multi-site sensor body motion detection, real-time monitoring carried out on the stairs for different postures and multi-finger movement. 4, the wireless wearable sensor successfully achieved full frequency synchronization monitoring body movement, speed, and amplitude information of the time span. The prepared conductive design work natural polymer hydrogel wireless wearable sensors exhibit a broad application prospect in medical rehabilitation and body-movement detecting field.

Figure 4. wireless wearable human motion monitoring sensor. a-b: the process of monitoring the movement of the stairs; c: monitoring finger movement.The research results with \”Super-Stretchable, Elastic and Recoverable IonicConductive Hydrogel for Wireless Wearable Stretchable Sensor\” in the title, published in

\” Journalof Materials Chemistry A \” (DOI: 10.1039 / D0TA02902E). Postdoctoral Huang Hailong and doctoral Han Lu as a co-first author, Professor Xu Min, a professor Panli Kun and Dr. Xu Xingtao for the corresponding author. The research was supported by the National Natural Science Foundation of China (No. 21875068) of.