一种抗冻耐低温的纤维状应变传感器件制备及性能研究

Wearable sensors are core components of flexible and wearable electronics, which have attracted enormous attention in recent years. Wearable sensors exert a significant influence on the design and function of the wearable electronics. A great number of wearable sensors with unique structural features and novel functions have emerged. .Nevertheless, the practicality of wearable sensors is still limited by their low sensitivity and stretchability, weak integratio, and complicate fabrication. Especially, few concerns are raised about the chronic stability and durability of the wearable sensors in extreme environmental, which severely restricts their development and practical application in the future..In this proposal, we develop fiber-shaped sensors by employing ionic liquid gels (IL-gels) and carbon nanotubes (CNTs) as functional materials. Herein, the equilibrium states of IL-gels will change upon mechanical stimuli, which therefore would result in electrical potentials. To balance the potential changes in IL-gels, electrons will flow from one CNTs electrode to the other CNTs electrode through external circuit, thus a continuous output signal would produce. Meanwhile, ionic liquid locking in gels will render the sensor to tolerate the low temperature and maintain all the properties under extreme environment, which are important for practical applications at subzero temperatures. Moreover, the dependence of the performance on several crucial parameters including the constituent, structure, morphology of the IL-gels and CNTs will also be systemically investigated to develop a series of high performance fiber-shaped sensors. In addition, we will study the stimuli-responsive mechanism of fiber-shaped sensors at subzero temperatures, exploring potential adaptability in the high-altitude and cold area.

柔性可穿戴传感器件是可穿戴电子设备的核心部件，对其结构和功能有决定作用，是研究人员重点关注的领域。近年来具有不同结构和功能的可穿戴传感器件大量涌现，但是目前可穿戴传感器件的灵敏度和拉伸性低，集成能力弱，以及制备过程复杂，特别是对极端环境下可穿戴传感器件的稳定性和耐受性缺乏必要的研究，严重制约了可穿戴传感器件的进一步发展和实际应用。.本项目提出构建一类纤维状传感器件：重点利用离子液体凝胶在外力作用下内部电荷迁移扩散形成流动电势差、并在碳纳米管感应电极表面诱导产生静电荷的原理，构建纤维状传感器件。离子液体将会赋予器件低温耐受性，使其在高寒环境中保持性能稳定。本项目将系统研究离子液体凝胶和碳纳米管电极的宏观组成，微观结构和形貌对器件性能的影响。还将深入探讨器件在低温条件下的刺激-响应机制，最终获得一类性能良好，可适用于高海拔寒冷地区的纤维状传感器件。

柔性电子技术是以柔性材料为基础，在物理、化学、材料、电子、生物和医学等多学科高度交叉融合基础上形成的颠覆性科学技术。柔性电子器件具有质轻、便携、可大面积加工和适应性强等优点，随着其崛起和不断发展，未来将会深刻变革甚至完全颠覆传统硅基电子技术的物理形态和运行模式。柔性可穿戴电子器件能实现与人体、环境的高效交互共融，进而实现环境刺激信息和生命特征信号的获取、传输、处理、显示以及能源的柔性化，已在人机信息交互、生命体征监测、便携式能源供给等领域显示出广泛的应用前景。但是如何在单一柔性可穿戴器件上实现刺激信息的响应、存储，自诊断、自修复和自适应等各种复杂功能的高度集成；如何确保器件在极端条件和特殊环境中的效率和稳定性，仍是当前制约其发展和应用的关键问题。.纤维状器件独特的一维线状结构，以及良好的拉伸性和屈服性，能够承受多种复杂力学形变，感知不同形式的外界刺激信号，更容易实现多功能集成，因此是柔性可穿戴器件的重要组件。本项目首先利用干法纺丝和浸涂方法制备了适用于宽温范围的离子液体凝胶/碳纳米管复合纤维传感器件，其次将具有导电、抗冻、抑菌和自愈合功能的材料和高分子凝胶网络相结合，利用微流控纺丝技术制备了具有同轴结构的纤维状柔性可穿戴传感器件。通过在内外层纺丝液中添加不同特征功能组分，在单根纤维器件上面实现了高强度、抗冻、拉伸、自修复和抑菌等多种功能的集成。在纤维状柔性可穿戴传感器件结构创新设计和制备以及柔性可穿戴传感器件智能水平、稳定性、适应性的提高等方面取得了重要突破。另外，针对目前柔性可穿戴电子器件导电聚合物凝胶易冻结，导致其电学和力学性能受限的普遍问题，采用液氮快速冷冻制备了一种具有双重抗冻机制聚合物冰凝胶，通过提高导电聚合物凝胶抗冻能力，将柔性可穿戴电子器件的工作温度拓展到了极端低温条件下（-80°C）。上述工作为发展具有极端环境适应性的柔性可穿戴器件提供了科学依据和技术支持。