Polymers
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2024
·Vol. 16
·期 1
·150
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IF 4.7
Xiangyu He,Jiaqi Lu,Feng Gao,Shurong Dong,Juan Li,Hao Jin,Jikui Luo
Poly(vinylidene fluoride-trifluorethylene) (P(VDF-TrFE)) has promising potential applications in radio-frequency filters due to their excellent piezoelectric properties, flexibility, and stability. In this paper, a flexible film bulk acoustic wave filter is investigated based on P(VDF-TrFE) as piezoelectric film. A new method based on three-step annealing is developed to efficiently remove the porosity inside the P(VDF-TrFE) films so as to improve its properties. The obtained film achieved high β-phase content beyond 80% and a high piezoelectric coefficient of 27.75 pm/V. Based on the low porosity β-phase films, a flexible wide-band RF filter is designed, which consists of a bulk acoustic wave resonator and lumped inductor-capacitor elements as a hybrid configuration. The resonator sets the filter’s center frequency, while the lumped LC-based matching network extends the bandwidth and enhances out-of-band rejection. The testing results of the proposed wide-band filter show its good performance, with 12.5% fractional bandwidth and an insertion loss of 3.1 dB. To verify the possibility of folding and stacking the flexible bulk acoustic wave devices for high-density multi-filter integration in MIMO communication, bending tests of the filter are also conducted with the bending strain range up to 5500 με. The testing results show no noticeable performance degradation after four bending cycles. This work demonstrates the potential of β-phase P(VDF-TrFE) bulk acoustic wave filters to expand the scope of future flexible radio-frequency filter applications.
研究领域:
材料科学
·
电子工程
·
射频技术
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DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2025
·
IF 5.7
Jizhong Deng,Guoxiang Zhang,Ya Yang,Wenjun Zhu,Zhiyi Wu,Yuanyu Wang
The development of wearable technology has been driven by the increasing demand for flexible and sensitive sensors that can utilize body motion to generate electricity or acquire physiological data for health assessment and rehabilitation. In this work, piezoelectric materials K 0.5 Na 0.5 NbO 3 nanoparticles (KNN NPs), synthesized through a one-step hydrothermal method, were integrated into poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] films to enhance their electrical properties for application in wearable piezoelectric nanogenerator (PENG) sensors. The maximum content of β phase in the composite film is as high as 83.1%, which may be attributed to the enhancement of polar interface interactions. The PENG sensors exhibited an open-circuit voltage of 12 V, a short-circuit current of 0.86 μA, and a peak power of 3.18 μW under optimal load, showcasing superior performance and stability over 4700 cycles. Monitoring results from human body motion demonstrated the potential application prospects of PENG sensors in motion analysis and medical rehabilitation.
研究领域:
材料科学
·
生物医学工程
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DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Jizhong Deng,Qi Sun,Zhiyi Wu,Yuanyu Wang
The self-driven flexible piezoelectric sensor has wide application prospects in areas such as health monitoring, human-machine interaction, and warning detection due to its advantages of non-toxicity and high sensitivity. In this study, a composite film of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] doped with NaNbO 3 (NN) was prepared by electrospinning. The highly oriented NN particles promote the formation of P(VDF-TrFE) β phase, reaching a maximum β phase content of 91%. Under mechanical motion at a frequency of approximately 3 Hz, the piezoelectric nanogenerator (PENG) fabricated from the nanofiber membrane achieved a maximum piezoelectric output of 17.3 V and 12 V in the transverse and longitudinal piezoelectric responses, respectively. With an external load of 100 MΩ, the PENG obtained a maximum power density of 0.67 μW/cm². Additionally, the PENG sensor exhibited sensitivity to various human activities and demonstrated high sensitivity and rapid response in monitoring the status of the proposed door lock opening/closing, highlighting its enormous potential in security monitoring applications.
研究领域:
材料科学
·
传感器技术
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Danle Lin,Ziyu Zhou,Mengdan Zhang,Songyou Yao,Lingling Yuan,Meng Xu,Xiaoyue Zhang,Xiaoli Hu
Biophysical and biochemical cues of biomaterials can regulate cell behaviors. Dental pulp stem cells (DPSCs) in pulp tissues can differentiate to odontoblast-like cells and secrete reparative dentin to form a barrier to protect the underlying pulp tissues and enable complete pulp healing. Promotion of the odontogenic differentiation of DPSCs is essential for dentin regeneration. The effects of the surface potentials of biomaterials on the adhesion and odontogenic differentiation of DPSCs remain unclear. Here, poly(vinylidene fluoride-trifluoro ethylene) (P(VDF-TrFE)) films with different surface potentials were prepared by the spin-coating technique and the contact poling method. The cytoskeletal organization of DPSCs grown on P(VDF-TrFE) films was studied by immunofluorescence staining. Using atomic force microscopy (AFM), the lateral detachment forces of DPSCs from P(VDF-TrFE) films were quantified. The effects of electrical stimulation generated from P(VDF-TrFE) films on odontogenic differentiation of DPSCs were evaluated in vitro and in vivo. The unpolarized, positively polarized, and negatively polarized films had surface potentials of −52.9, +902.4, and −502.2 mV, respectively. DPSCs on both negatively and positively polarized P(VDF-TrFE) films had larger cell areas and length-to-width ratios than those on the unpolarized films (P < 0.05). During the detachment of DPSCs from P(VDF-TrFE) films, the average magnitudes of the maximum detachment forces were 29.4, 72.1, and 53.9 nN for unpolarized, positively polarized, and negatively polarized groups, respectively (P < 0.05). The polarized films enhanced the mineralization activities and increased the expression levels of the odontogenic-related proteins of DPSCs compared to the unpolarized films (P < 0.05). The extracellular signal-regulated kinase (ERK) signaling pathway was involved in the odontogenic differentiation of DPSCs as induced by surface charge. In vivo, the polarized P(VDF-TrFE) films enhanced adhesion of DPSCs and promoted the odontogenic differentiation of DPSCs by electrical stimulation, demonstrating a potential application of electroactive biomaterials for reparative dentin formation in direct pulp capping.
研究领域:
生物材料
·
干细胞生物学
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组织工程
·
牙科材料
·
细胞粘附
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分化
·
信号转导
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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）