陶瓷纳米纤维基柔性压力传感器的制备及应用

FABRICATION AND APPLICATIONS OF CERAMIC NANOFIBERS-BASED FLEXIBLE PRESSURE SENSOR

付敏

11849412

硕士

物理学

赵悦、黄思雅

2020-05-28

2020-07-12

哈尔滨工业大学

深圳

随着5G技术的快速发展和应用，作为未来新型电子装备和人机交互界面的柔性传感器件受到人们的广泛关注。柔性压力传感器为可穿戴设备及软机器人提供生理信号监控、运动检测以及触觉感知等多种功能，具有重要的研究价值。受制于传统电子器件原材料的种类及性能要求，目前主流的可穿戴设备均采用硬质材料。人体皮肤具有柔性且湿度可调节，长时间接触刚性且气密性高的材料将使人体产生不适感甚至发生炎症反应。为了实现可适用于生物体长期舒适佩戴的传感器件，需要将可穿戴设备柔性化，并提高器件的透气性能。目前，大多数柔性传感器采用高分子聚合物材料，如聚二甲基硅氧烷（PDMS）、水凝胶、离子凝胶等。这些材料对使用环境要求苛刻，易在高温、低湿度、紫外光照等条件下发生降解，从而导致器件失效。如何提高柔性传感器在不同环境下应用的性能稳定性，这对材料选择和器件设计提出了更高的要求。陶瓷具有抗腐蚀性、化学性质稳定和高熔点等特性，二氧化钛（TiO2）作为一种具有多种优异性质的陶瓷材料，因其生物相容性好以及原材料丰富而得到广泛应用。本课题利用静电纺丝法制备得到一种基于TiO2纳米纤维网络结构的柔性薄膜。该薄膜具有极轻的质量，出色的透气性，以及良好的力学柔性，是作为柔性透气压力传感器介电层的理想材料。基于这种材料，我们设计并制备了一种高灵敏、透气且耐高温的电容式柔性压力传感器。该陶瓷压力传感器展现出高灵敏度（~4.4 kPa-1），超低检测极限（< 0.8 Pa），快速响应速度（响应时间< 16 ms）以及优异的循环稳定性（50 000个压缩循环和10 000个弯曲循环）。进一步的力学测试结果表明，陶瓷纳米纤维薄膜具有优异的机械回弹性，在10％压缩应变循环100次后产生2.2％的残余应变。这与聚乙烯醇（PVA）和聚偏二氟乙烯（PVDF）纳米纤维的不可逆应变形成鲜明对比，其形变量分别为8.0%和7.4%。通过使用织物电极，我们成功制备了一种完全透气且可穿戴的陶瓷压力传感器，该传感器能够用于实时健康监测和运动检测。此外，采用耐高温碳纤维电极得到的陶瓷电容传感器可以实现高温应用。在370 ℃的条件下，传感器的灵敏度达到0.028 kPa-1，同时可耐受约1300 ℃的瞬时高温，显示其在极端环境中巨大的应用潜力。

With the rapid development and application of 5G technology, flexible sensor devices, which are new electronic equipment and human-computer interaction interfaces in the future, have attracted widespread attention. Flexible pressure sensors provide various functions such as physiological signal monitoring, motion detection, and tactile sensing for wearable devices and soft robots, and have important research value. Limited by the types and performance requirements of traditional electronic raw materials, current mainstream wearable sensors are made of rigid materials. Human skin is flexible and humidity-adjustable. Prolonged contact with rigid and air-tight materials will cause discomfort and even inflammation. In order to realize sensors that can be comfortably worn by organisms for a long time, it is necessary to make the wearable sensor flexible and improve the breathability of the sensor.Currently, most flexible sensors use polymer materials, such as polydimethylsiloxane (PDMS), hydrogels, ionic gels, etc. These materials have strict requirements on the environments and are prone to degradation under conditions such as high temperature, low humidity, and ultraviolet light, leading to device failure. How to improve the performance stability of flexible sensors in different environments has put forward higher requirements on material selection and device design. Ceramic has the characteristics of corrosion resistance, chemical stability, and high melting point. As a ceramic material with many excellent properties, titanium dioxide (TiO2) is widely used because of its good biocompatibility and abundance. In this paper, a flexible thin film based on the TiO2 nanofiber network was prepared by electrostatic spinning. The film has extremely light weight, excellent breathability, and good mechanical flexibility, and is an ideal material for the dielectric layer of a breathable flexible pressure sensor. Based on this material, we designed and fabricated a highly sensitive, breathable, and high-temperature- resistant capacitive flexible pressure sensor. The ceramic pressure sensor exhibits high sensitivity (~ 4.4 kPa-1), ultra-low detection limit (< 0.8 Pa), fast response speed (response time < 16 ms), and excellent cyclic stability (50 000 compression cycles and 10 000 bending cycles). Further mechanical test results showed that the ceramic nanofiber film has excellent mechanical resilience, resulting in a residual strain of 2.2% after 100 cycles with a 10% compression strain. This is in stark contrast to the irreversible strain of polyvinyl alcohol (PVA) and polyvinylidene fluoride (PVDF) nanofibers, which are 8.0% and 7.4%, respectively. By employing fabric electrodes, a fully breathable and wearable ceramic pressure sensor was successfully prepared. The sensor can be used for real-time health monitoring and motion detection. In addition, the ceramic flexible sensor made of high-temperature-resistant carbon fiber electrodes can achieve high-temperature applications. At 370 ℃, the sensitivity of the sensor reaches 0.028 kPa-1, and it can withstand a transient high temperature of about 1300 ℃, showing its great application potential in extreme environments.

陶瓷纳米纤维 柔性压力传感器 透气可穿戴 健康监测 耐高温

ceramic nanofibers flexible pressure sensor breathable and wearable health monitoring high-temperature-resistant

中文

联合培养

南方科技大学

付敏. 陶瓷纳米纤维基柔性压力传感器的制备及应用[D]. 深圳. 哈尔滨工业大学,2020.