Tsinghua Shenzhen International Graduate School, Tsinghua University, University Town of Shenzhen, Shenzhen 518055, China.
Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, University Town of Shenzhen, Shenzhen 518055, China.
Sensors (Basel). 2020 Jun 29;20(13):3651. doi: 10.3390/s20133651.
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.
生物细胞或组织在日常生理活动中产生的生物电化学或电生理信号与身体状态和器官功能密切相关，因此被广泛应用于临床诊断、健康监测、智能控制和人机交互等领域。Ag/AgCl 电极与湿导电凝胶配合使用，可以通过电极采集这些生物电信号，并以脑电图、心电图、肌电图、眼电图等形式记录下来。然而，Ag/AgCl 湿电极配合使用凝胶带来的不便、不稳定性和感染问题，无法满足长期信号采集的需求，特别是在可穿戴应用中。因此，人们的研究重点转向了无需凝胶或粘合剂即可工作的干电极。本文对用于监测生物电信号的干电极的发展进行了回顾性概述，包括传感原理、材料选择、器件制备和测量性能。此外，还讨论了干电极在材料、制造技术和可穿戴性能方面的局限性挑战。最后，分析了不同干电极的发展障碍和应用优势，进行了对比，揭示了未来研究的方向。
