Zheng Wenxiang, Wang Zhibin, Zhang Mengnan, Niu Yanxin, Wu Yuchuan, Guo Pengxin, Zhang Niu, Meng Zihui, Murtaza Ghulam, Qiu Lili
School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
Analysis & Testing Centre, Beijing Institute of Technology, Beijing 100081, China.
Gels. 2024 Aug 1;10(8):506. doi: 10.3390/gels10080506.
Photoelectric dual-mode sensors, which respond to strain signal through photoelectric dual-signals, hold great promise as wearable sensors in human motion monitoring. In this work, a photoelectric dual-mode sensor based on photonic crystals hydrogel was developed for human joint motion detection. The optical signal of the sensor originated from the structural color of photonic crystals, which was achieved by tuning the polymethyl methacrylate (PMMA) microspheres diameter. The reflective peak of the sensor, based on 250 nm PMMA PCs, shifted from 623 nm to 492 nm with 100% strain. Graphene was employed to enhance the electrical signal of the sensor, resulting in a conductivity increase from 9.33 × 10 S/m to 2 × 10 S/m with an increase in graphene from 0 to 8 mg·mL. Concurrently, the resistance of the hydrogel with 8 mg·mL graphene increased from 160 kΩ to 485 kΩ with a gauge factor (GF) = 0.02 under 100% strain, while maintaining a good cyclic stability. The results of the sensing and monitoring of finger joint bending revealed a significant shift in the reflective peak of the photoelectric dual-mode sensor from 624 nm to 526 nm. Additionally, its resistance change rate was measured at 1.72 with a 90° bending angle. These findings suggest that the photoelectric dual-mode sensor had the capability to detect the strain signal with photoelectric dual-mode signals, and indicates its great potential for the sensing and monitoring of joint motion.
光电双模传感器通过光电双信号对应变信号做出响应，在人体运动监测中作为可穿戴传感器具有巨大潜力。在这项工作中，开发了一种基于光子晶体水凝胶的光电双模传感器用于人体关节运动检测。该传感器的光信号源自光子晶体的结构色，这是通过调节聚甲基丙烯酸甲酯（PMMA）微球直径实现的。基于250 nm PMMA光子晶体的传感器，其反射峰在100%应变下从623 nm移至492 nm。采用石墨烯来增强传感器的电信号，随着石墨烯从0增加到8 mg·mL，电导率从9.33×10 S/m增加到2×10 S/m。同时，含有8 mg·mL石墨烯的水凝胶在100%应变下，电阻从160 kΩ增加到485 kΩ，应变系数（GF）= 0.02，同时保持良好的循环稳定性。手指关节弯曲的传感和监测结果表明，光电双模传感器的反射峰从624 nm显著移至526 nm。此外，在90°弯曲角度下测得其电阻变化率为1.72。这些发现表明光电双模传感器有能力通过光电双信号检测应变信号，并显示出其在关节运动传感和监测方面的巨大潜力。
