Piezoelectric d33 coefficients in foamed and layered polymer piezoelectrets from dynamic mechano-electrical experiments, electro-mechanical resonance spectroscopy and acoustic-transducer measurements
Piezoelectric d33 coefficients in foamed and layered polymer piezoelectrets from dynamic mechano-electrical experiments, electro-mechanical resonance spectroscopy and acoustic-transducer measurements
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DOI：
10.1088/0957-0233/23/3/035604
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发表时间：
2012-03-01
影响因子：
2.4
通讯作者：
Gerhard, Reimund
中科院分区：
文献类型：
--
作者：
Fang, Peng;Hollaender, Lars;Gerhard, Reimund
压电驻极体是一种新型的换能器材料，在传感器和执行器中有着广泛的应用。本文综述并比较了三种测定压电驻极体压电d（33）系数的方法。制备了两种类型的压电驻极体，聚萘二甲酸乙二醇酯（PEN）泡沫聚合物压电驻极体和氟化乙烯-丙烯（FEP）共聚物层压电驻极体，并通过动态，共振和声学方法进行了测量。动态测试表明，PEN泡沫试样的d（33）系数随应力的增加而明显减小，但在机械疲劳试验中连续动态测试1800次后，d（33）系数仍能保持80%。共振测量表明PEN泡沫和FEP层样品都表现出清晰的机电共振。PEN-泡沫样品显示出在1至12 MPa范围内的弹性模量和高达500 pC N-1的d（33）值，而FEP-层样品显示出约0.3 MPa的均匀弹性模量和约280 pC N-1的d（33）值。声学测量结果表明，PEN泡沫和FEP层样品在5.7至20 kHz的范围内表现出稳定的频率响应。此外，用不同实验方法得到的d（33）系数之间也有很好的一致性，证实了三种方法的可靠性。
Piezoelectrets are novel transducer materials which can be widely applied in sensors and actuators. Here, three techniques for determining piezoelectric d(33) coefficients of piezoelectrets are reviewed and compared. Two types of piezoelectrets, polyethylene-naphthalate (PEN) polymer-foam piezoelectrets and fluorinated ethylene-propylene (FEP) copolymer-layer piezoelectrets, have been prepared and measured by means of dynamic, resonance, and acoustical methods. The dynamic measurements show that the d(33) coefficient of PEN-foam samples clearly decreases with increasing stress, but 80% of the initial d(33) can be retained after 1800 cycles of a continuous dynamic measurement in a mechanical fatigue test. The resonance measurements demonstrate that both PEN-foam and FEP-layer samples exhibit clear electro-mechanical resonances. PEN-foam samples show elastic moduli in the range from 1 to 12 MPa and d(33) values up to 500 pC N-1, while FEP-layer samples show homogeneous elastic moduli of about 0.3 MPa and d(33) values of about 280 pC N-1. The acoustical measurements reveal that both PEN-foam and FEP-layer samples exhibit stable frequency responses in the range from 5.7 to 20 kHz. In addition, d(33) coefficients obtained with different experimental methods are in good agreement with each other, which confirms the reliability of all three techniques.