Liu Mingran, Liu Yang, Zhou Limin
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
School of System Design and Intelligent Manufacturing, Southern University of Science and Technology, Xueyuan Road 1088, Shenzhen 518055, China.
Micromachines (Basel). 2021 May 23;12(6):602. doi: 10.3390/mi12060602.
With the development of human healthcare devices, smart sensors, e-skins, and pressure sensors with outstanding sensitivity, flexibility, durability and biocompatibility have attracted more and more attention. In this paper, to develop a novel flexible pressure sensor with high sensitivity, different poly (vinylidene fluoride-trifluoroethylene) (PVDF-TrFE)-based composite membranes were fabricated, characterized and tested. To improve the β-phase crystallinity and piezoelectricity of the membranes, and for the purpose of comparison, nano ZnO particles with different concentrations (99:1, 9:1 in a weight ratio of PVDF-TrFE to ZnO) were, respectively added into PVDF-TrFE polymer acting as a nucleating agent and dielectric material. To facilitate the formation of β-phase crystal, the membranes were fabricated by electrospinning method. After the electrospinning, an annealing process was conducted to the fabricated membranes to increase the size and content of β-phase crystal. Then, the fabricated PVDF-TrFE membranes, acting as the core sensing layer, were, respectively built into multiple prototype sensors in a sandwich structure. The sensitivity of the prototype sensors was tested by an auto-clicker. The stimulation of the auto-clicker on the prototype sensors generated electrical signals, and the electrical signals were collected by a self-built testing platform powered by LabVIEW. As a result, combining the addition of ZnO nanofillers and the annealing process, a highly sensitive pressure sensor was fabricated. The optimal peak-to-peak voltage response generated from the prototype sensor was 1.788 V which shows a 75% increase compared to that of the pristine PVDF-TrFE sensor. Furthermore, a human pulse waveform was captured by a prototype sensor which exhibits tremendous prospects for application in healthcare devices.
随着人类医疗保健设备的发展，具有出色灵敏度、柔韧性、耐用性和生物相容性的智能传感器、电子皮肤和压力传感器越来越受到关注。在本文中，为了开发一种新型的高灵敏度柔性压力传感器，制备、表征并测试了不同的聚（偏二氟乙烯-三氟乙烯）（PVDF-TrFE）基复合膜。为了提高膜的β相结晶度和压电性，并且为了进行比较，将不同浓度（PVDF-TrFE与ZnO的重量比为99:1、9:1）的纳米ZnO颗粒分别添加到PVDF-TrFE聚合物中，作为成核剂和介电材料。为了促进β相晶体的形成，通过静电纺丝法制备膜。静电纺丝后，对制备的膜进行退火处理，以增加β相晶体的尺寸和含量。然后，将制备的PVDF-TrFE膜作为核心传感层，分别构建成多种三明治结构的原型传感器。通过自动点击器测试原型传感器的灵敏度。自动点击器对原型传感器的刺激产生电信号，电信号由由LabVIEW供电的自制测试平台收集。结果，结合ZnO纳米填料的添加和退火工艺，制备了一种高灵敏度压力传感器。原型传感器产生的最佳峰峰值电压响应为1.788 V，与原始PVDF-TrFE传感器相比提高了75%。此外，原型传感器捕获了人体脉搏波形，在医疗保健设备中具有巨大的应用前景。
