Advanced Interdisciplinary Research Center for Flexible Electronics, Academy of Advanced Interdisciplinary Research, Xidian University, Xi'an 710071, China.
State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China.
ACS Appl Mater Interfaces. 2024 Mar 13;16(10):12974-12985. doi: 10.1021/acsami.4c01042. Epub 2024 Feb 28.
Foot activity can reflect numerous physiological abnormalities in the human body, making gait a valuable metric in health monitoring. Research on flexible sensors for gait monitoring has focused on high sensitivity, wide working range, fast response, and low detection limit, but challenges remain in areas such as elasticity, antibacterial activity, user-friendliness, and long-term stability. In this study, we have developed a novel capacitive pressure sensor that offers an ultralow detection limit of 1 Pa, wide detection ranges from 1 Pa to 2 MPa, a high sensitivity of 0.091 kPa, a fast response time of 71 ms, and exceptional stability over 6000 cycles. This sensor not only has the ability of accurately discriminating mechanical stimuli but also meets the requirements of elasticity, antibacterial activity, wearable comfort, and long-term stability for gait monitoring. The fabrication method of a dual dielectric layer and integrated composite electrode is simple, cost-effective, stable, and amenable to mass production. Thereinto, the introduction of a dual dielectric layer, based on an optimized electrospinning network and micropillar array, has significantly improved the sensitivity, detection range, elasticity, and antibacterial performance of the sensor. The integrated flexible electrodes are made by template method using composite materials of carbon nanotubes (CNTs), two-dimensional titanium carbide TiCT (MXene), and polydimethylsiloxane (PDMS), offering synergistic advantages in terms of conductivity, stability, sensitivity, and practicality. Additionally, we designed a smart insole that integrates the as-prepared sensors with a miniature instrument as a wearable platform for gait monitoring and disease warning. The developed sensor and wearable platform offer a cutting-edge solution for monitoring human activity and detecting diseases in a noninvasive manner, paving the way for future wearable devices and personalized healthcare technologies.
足部活动可以反映人体的许多生理异常，使步态成为健康监测的一个有价值的指标。用于步态监测的柔性传感器的研究集中在高灵敏度、宽工作范围、快速响应和低检测限上，但在弹性、抗菌活性、用户友好性和长期稳定性等方面仍存在挑战。在这项研究中，我们开发了一种新型电容式压力传感器，其检测限低至 1 Pa，检测范围从 1 Pa 到 2 MPa，灵敏度高为 0.091 kPa，响应时间快为 71 ms，在 6000 次循环后具有出色的稳定性。该传感器不仅具有准确区分机械刺激的能力，而且满足弹性、抗菌活性、佩戴舒适性和长期稳定性等要求，可用于步态监测。双介电层和集成复合电极的制造方法简单、经济高效、稳定，适合大规模生产。其中，基于优化的静电纺丝网络和微柱阵列的双介电层的引入，显著提高了传感器的灵敏度、检测范围、弹性和抗菌性能。采用模板法制备的集成柔性电极由碳纳米管(CNTs)、二维碳化钛 TiCT (MXene)和聚二甲基硅氧烷(PDMS)复合材料制成，在导电性、稳定性、灵敏度和实用性方面具有协同优势。此外，我们设计了一个智能鞋垫，将制备好的传感器与一个微型仪器集成在一起，作为一个用于步态监测和疾病预警的可穿戴平台。所开发的传感器和可穿戴平台为非侵入式监测人体活动和检测疾病提供了一种前沿解决方案，为未来的可穿戴设备和个性化医疗技术铺平了道路。
