驻极体的研究现状

驻极体是电介质物理、材料科学、传感器工程及生物医学的重要交叉学科。近年来，驻极体在生物驻极体、驻极体的应用及有机驻极体的非线性光学效应等方面取得了瞩目的进展。文章就上述几个问题，从材料制备、实验方法和驻极体的应用等方面进行了综述。     

聚全氟乙丙烯驻极体传声器的灵敏度稳定性分析

聚全氟乙丙烯驻极体传声器的灵敏度稳定性分析电子工业部三所程一、引言自６０年代以来，随着对驻极体研究的不断深入和驻极体材料性能的改进提高，驻极体在理想贮存条件下的稳定性问题，已经解决，因而促进了驻极体传声器产业的迅速发展。驻极体电荷的稳定性是决定驻极体...     

用热脉冲法测量双面镀金属膜的薄膜驻极体的体内电荷重心的研究

由于驻极体在传感、过滤，辐射计量等方面的广泛应用，驻极体的研究已成为电介质物理、电子材料和传感器领域中的重要学科，对驻极体的电荷储存、脱阱和输运的研究是研究驻极体的机理，驻极体材料的形成和改性，驻极体器件的开发和应用的基础。研究各种条件下驻极体体内的电荷重心是实现上述目标的重要方法，本文介绍我们实验室建立的国内第一套测量双面镀金属膜的驻极体薄膜的体内电荷重心的热脉冲装置，并对双面热脉冲和单面热脉冲     

聚二氯对苯撑二甲基(PDCPX)诸驻极体等温放电的行为方程及其应用条件

1984年笔者分析了PDCPX驻极体等温放电的实验记录后，得出了该驻极体表面电位等温衰减的实验公式。此后于1996年重建了结晶聚合物中的跳跃电流公式，导出了结晶聚合物驻极表面电位等温衰减的行为方程，完成了上述实验公式的理论解释。现已发现该方程只适用于完全干燥的驻极体。     

关于近代静电驻极体等温衰减规律的探索——兼及ECM的使用寿命及其驻极体的电阻率的估算

简述了驻极体的起源和历史上对聚合物驻极体等温放电的探索。详述了探索历程,回答了半个多世纪以来驻极体衰减的诸多未解难题。从繁多的实验数据中在人类历史上找到了驻极体等温放电的实验式和ECM中的驻极体在高温中和常温中两个独立的等温放电的行为方程,进而与生产实际相合,近似地建立了估算ECM使用寿命及其中驻极体电阻率的方法和计算式。     

《驻极体与数字传声器阵列论文集》介绍

这是一本有关驻极体、ECM及微型数字传声器阵列的论文集,精选了二十二篇重要且实用的论文。本论文集共分四集:一曰驻极体与驻极体传声器,二曰驻极体等温衰减规律的探索,三曰聚合物驻极体的制备,四曰新型传声器原理及应用。主要选编了东南大学驻极体工作者欧阳毅与其合作者,为配合电子部的电声厂的ECM试制、生产,从1973年至2011     

结晶聚合物驻极体中的跳跃电流和电荷储存

推导了聚合物和聚合物驻极体中的跳跃电流公式。依据这些公式导出了聚合物驻极体等温放电的理论公式，用驻极体等温衰减的数据估算出电子跳跃的步距约为10^-8m，用X光衍射实验测得的聚合物中结晶区的线度也是10^-8m量极。这从实验上支持上述公式的成立。理论和实验都证明稳态地储存的电荷几乎都被驻极体中的结晶区的能带所俘获。     

驻极体表面电位均匀及同步衰减的条件

关于驻极体表面电位异步衰减的现象，已在很多场合观察到了，但其原因并未得到解释。本文的目的就在于依据新近理论，找出驻极体表面电位均匀且同步衰减的条件。     

聚四氟乙烯驻极体振膜的电晕极化

本文介绍了国产10μm 厚的聚四氟乙烯驻极体振膜的电晕极化方法,通过电晕极化驻极体振膜同热极化驻极体振膜在稳定性方面的测试比较,表明电晕极化驻极体的稳定性是良好的,可以在生产实践中替代热极化驻极体。     

电声传感聚合物驻极体发展的新动态

驻极体薄膜作为电声传感器件应用已有几十年的历史，近年来国际上对多孔驻极体材料的压电效应引起了业内人士的高度重视和极大兴趣。聚合物薄膜压电传感嚣随着新型薄膜材料的发展而有可能成为未来驻极体应用的一个高层次的领域和更新换代的产品。     

驻极体声传感器及其储电材料的现状

综述了驻极体声传感器及其储电材料近年来的迅猛发展。传统的FEP(tetrafluoroethylene—hexa—fluoropropylene copolymer)极体电容式声传感器及以铁电聚合物PVDF(poly vinylidene fluoride)家族为芯片的声传感器和超声抉能器仍焕发着青春活力。Si基微型驻极体声传感器的理论和实验研究已经日趋成熟，而用空间电荷型多孔聚合物驻极体压电薄膜为芯片可望研制出新一代声电和电声传感器、压力传感器和驱动器。     

High-response organic thin-film memory transistors based on dipole-functional polymer electret layers

A molecular design for the electret material of n-operating organic field-effect transistor-based (OFET) memories is introduced. A large memory window and high operating speed were achieved while the polar groups are connected to the polymer chain of polyimide, which plays the role of electret of a transistor memory device. The phase variation of electrical force microscopy images showed that polarization field induces charge trapping states on the surface of electret layer and accumulates charged carriers within the conducting channel of OFET to achieve high-performance memory and transistor simultaneously. An extra-large memory window was also obtained by introducing photo-induced charge transfer effect.     

Lifetime of electret microphones by thermal degradation analysis via electroacoustic measurements

Electronic equipment frequently utilises low cost electret microphones. In this paper, a complete accelerated life-test on commercial electret microphones is presented using thermal chamber testing. The test was conducted on the microphones under study at three different temperatures. After each thermal probe, the electroacoustic characteristics of each transducer was analysed for obtaining the degradation model. In the literature such tests have been performed through charge losses on the electret materials. Life models were obtained for the degradation failures revealed from the tests and a complete temperature model was then developed, which can calculate the useful life of the microphones under any of these conditions.     

电容换能器中的聚合物驻极体表面电位等温衰减解析式及其应用

本文依据驻极体内场推动介质中原有载流子的越垒电流等于驻极体电荷衰减时率的负值的物理过程,导出了电容换能器中聚合物驻极体表面电位等温衰减的解析式。该式与实验结果一致。据此,重建了驻极体高温外推法,解释了迄今为止的诸多驻极体稳定性实验现象。     

New Touch Actuator Based on the Foil-Electret Principle

A new touch actuator is described that consists of a single metalized foil electret, a number of independent metal backplate sections aligned with the holes of a front cover, and air gaps separating electret and backplate sections. The metal layer of the foil forms a transducer with capacitance Cawith each backplate section. The actuator is operated by touching the foil electret through one of the front-cover holes. For a trapezoidal displacement (duration2T) of the foil electret, the electrical output signal across a terminating resistorRconsists of a pair of oppositely poled spikes with duration comparable to RCa, if RCais smaller thanT. If RCais larger thanT, the electrical output approximates the displacement. For an electret with a charge density of10^{-8} C/cm^{2}, the measured pulse amplitudes due to touching are of the order of 0.3 to over 100 V depending on the applied force, and on the resistive and capacitive loading. The touch actuator is mechanically simple, reliable to use, inexpensive to produce, and can be made with an overall thickness of less than 0.5 cm. Apart from its potential use in telephone dials, it may also find applications as a key transducer in digital devices.     

A Micromachined Electret-Based Transponder for In Situ Radiation Measurement

This letter reports on the development of a micromachined passive transponder for in situ measurement of ionizing radiation. gamma-ray exposure is remotely measured by monitoring the resonance frequency change correlated with a change in the surface charge of an electret. This is achieved through a micromachined capacitor with a movable plate that is partially filled with a Teflon electret and connected in parallel with an inductor, forming a passive LC tank (a microionization chamber, 1.5 cm in diameter and 3 mm in thickness). Test results show that an exposure of 60 000 R from Cs¹³⁷ produces a 687-kHz resonance frequency shift (sensitivity of 11.45 kHz/kR)     

Programmable memory in organic field-effect transistor based on lead phthalocyanine

A nonvolatile organic field-effect transistor (OFET) with a polymeric electret as gate insulator and spun cast film of lead phthalocyanine (PbPc) as semiconductor channel is reported. Hysteresis induced by gate–bias stress was exploited to study nonvolatile memory effects. The observation of the hysteresis and memory window is proposed to originate from charge storage in the polymeric electret. The on state retention time for the OFET memory device is more than 5 h and the device can reproduce continuous write–read–erase–read switching cycles.     

More Than Energy Harvesting in Electret Electronics-Moving toward Next-Generation Functional System

Electrets are normally applied for energy conversion from mechanical vibration sources in the environment to electrical power without any friction, which induces electric device sustainability and mechanically robust. It functions for electron storage and electrostatic/triboelectric effect, whose electrical/mechanical performance dramatically benefits energy harvesters, self-powered sensors, and even intelligent/sustainable systems. To summarize the progress of electret-based electronics, this review proposes three key issues around enhanced energy harvesting toward sensors and sustainable systems. First, with the properties of long-term charge storage characteristics and the contactless mechanism for energy harvesting, the enhancement effect in electret from MEMS devices, porous microstructure devices, and multilayer electret devices are carefully assessed with the output power from various devices. Second, the multi-functional applications aspect along with the triboelectric coupling effect and artificial piezoelectric materials are discussed as future electret devices, for example, polydimethylsiloxane materials. Third, more than energy harvesting, machine learning-enabled methodology in electret electronics can be more reliable and sustainable, dramatically contributing to the living standard of the society. Electret technologies on the future development trends are finally analyzed and strengthened toward multifunctional, sustainable, and intelligent systems along with the upcoming technologies in coupling mechanism, artificial composite materials, and machine learning in data fusion.     

用恒流电晕充电改善聚丙烯驻极体的电荷贮存能力

本文通过恒压和恒流充电后的聚丙烯(Polypropyrene简称pp)驻极体的等效表面电位衰减曲线和开路TSD(Thermally Stimulated Discharge)电流谱线的测量,阐明了恒流电晕充电可使聚丙烯驻极体注入较大的体电荷。利用热脉冲技术确定恒流和恒压条件下电荷重心的迁移规律,说明了恒流电晕充电能明显地改善PP电荷的贮存稳定性。     

驻极体空气过滤材料消静电实验研究

选取4片不同级别的驻极体空气过滤材料,对滤料消除静电效应前后的计数效率和PM2.5净化效率等性能参数进行了试验研究,消静电方法采用的是异丙醇浸泡法,试验用气溶胶为KCl固态气溶胶。试验结果表明:采用异丙醇浸泡法能够在一定程度上消除驻极体过滤材料本身所带的静电;消除静电效应后滤料对不同粒径颗粒的计数效率均有所下降,特别是颗粒物粒径越小,过滤效率下降的幅度也越大;消静电后滤料对PM2.5的净化效率也有所下降。研究结果揭示了采用驻极体过滤材料制造而成的带静电过滤器在实际使用过程中可能存在的因静电消失后带来的效率下降风险,试验数据也能为将来空气过滤器国家相关标准的修订提供参考建议。