Micromachines
·
2021
·Vol. 12
·期 6
·602
·
IF 2.891
Mingran Liu,Yang Liu,Limin Zhou
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.Keywords:PVDF-TrFE;PVDF-TrFE/ZnO;β phase crystal;human pulsation sensor
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AIP Advances
·
2019
·Vol. 9
·期 11
·
IF 1.579
Zhang Jianwen,Cao Peng,Cui Zhaoliang,Wang Qian,Fan Fan,Qiu Minghui,Wang Xiaozu,Wang Zhaohui,Wang Yong
Membrane fouling can be efficiently mitigated by the vibration of the piezoelectric membrane stimulated by AC signals, but it is still a challenge to fabricate piezoelectric membranes with great efficiency, low energy-consumption, and no harm to the environment during its preparation. The present work provides a new approach to poly(vinylidene fluoride) (PVDF) membranes with piezoelectric properties by directly poling β-phase PVDF membranes using green diluents, which revealed better piezoelectric properties than poling α-phase PVDF membranes. Basically, absolute β-phase crystals of PVDF membranes were induced over thermally induced phase separation with the addition of Acetyl tributyl citrate (ATBC)/ionic liquid ([BMIM]PF 6 ), which are regarded as green and environment-friendly diluents. To endow the piezoelectric property to the β-phase PVDF membrane, a poling process was necessarily conducted. The effect of the poling process on the membrane structure, morphologies, properties, and performances was investigated. Meanwhile, a vibration test for both of the poled and unpoled membranes was performed in an excitation of the alternating signal. The results demonstrated that the poling process positively endowed the piezoelectric property to the PVDF membranes. The membrane structure, morphologies, and performances of the membranes were also changed to some extent by the poling process. Additionally, filtrations of the poled membrane both with and without electrical signals were carried out to test their antifouling performance on the CaCO 3 suspension system and BSA solution, respectively. It was observed that the stable flux of the membranes notably improved when subjected to an electrical AC signal. Thus, it depicted that the piezoelectric PVDF membrane directly poled from the β-phase possesses a promising antifouling performance due to its high piezoelectric vibration.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Ling-Zhi Huang,Yan Ding,Dan-Dan Li,Ming-Guo Ma
Cellulosic triboelectric materials have gained widespread attention in triboelectric nanogenerators (TENGs) recently due to their fascinating merits of renewability, biodegradability, and low cost. However, cellulose-based TENGs still are challenged by the low surface charge density of triboelectric materials. Herein, the negative charged cellulosic triboelectric materials are functionalized as triboelectric layers for self-powered sensors via an electrostatic spinning method, where the electrospun polyvinylidene fluoride (PVDF) nanofibers fill with the porous air-laid paper (AP), boosting the formation of polar β-phase crystals and a negative shift of the surface potential. The TENG constructed with PVDF/12 wt%@AP affords charge output of 60.7 μC m −2 and power output of 233.28 mW m −2 , and the as-prepared contact self-sensor presents unparalleled sensitivity of 6.20 V kPa −1 under pressures from 1.23 kPa to 5.0 kPa. In addition, we design the non-contact self-powered sensor, capable of recognizing different objects and accurately detecting human movements like walking, running, and jumping. Notably, the TENGs can also be used as a wireless sensor terminal for smart devices to provide convenient sensing functions. This β-phase cellulosic materials are a step toward wearable self-powered sensor systems that are durable to capture mechanical energy from the environment.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）