PVDF柔性传感器的制备研究

设计了一种PVDF柔性传感器结构,通过实验制备了高质量的PVDF压电薄膜,发现PVDF质量分数为15%的溶液具有很好的成膜能力。介绍了PVDF薄膜的制备方法和注意事项;设计了一种PVDF柔性传感器的制备流程,总结了其制备过程中的工艺方法和关键步骤,可为PVDF柔性传感器的制备提供借鉴和参考。     

Zn/PVDF复合薄膜的结构和压电性能研究

为获得新型高性能铁电聚合物薄膜的制备技术,采用热压法工艺制备了Zn颗粒/聚偏二氟乙烯(PVDF)金属聚合物压电薄膜.通过X射线衍射仪(XRD)和傅立叶红外光谱仪(FTIR)对晶形结构进行了分析,运用准静态压电测试仪测量了复合薄膜的压电应变常数d33.结果表明:Zn颗粒的加入使复合薄膜诱导产生β晶相,而热压制备的纯PVDF薄膜只含有非极性的α晶相;同时,Zn/PVDF复合薄膜的压电应变常数d33相比于PVDF薄膜明显提高,具有较强的压电性;并且,压电性能明显受到薄膜中氧化锌含量的影响,在一定范围内,随着Zn含量的增加,复合薄膜的压电应变常数也随之增加.     

PZT/PVDF压电复合材料微观结构与性能研究

采用溶液混合法制备 PZT/ PVDF压电复合材料。首先用固相法制备出适合溶液混合的 PZT陶瓷粉末 ,并且通过陶瓷粉末对 PVDF的吸收量选择乙醇为 PVDF的溶剂进行混合 ,然后烘干制备出 PZT/ PVDF复合粉末 ,再成型极化。实验结果表明这种复合方法提高了 PZT陶瓷颗粒在 PVDF有机基体中的分散度 ,使制得的材料内部均匀 ,结构致密 ,从而提高了 PZT/ PVDF压电复合材料的压电和介电性能。     

碳纳米管改性0-3型压电复合材料的制备与性能研究

以碳纳米管改性聚偏氟乙烯(PVDF)为基体,锆钛酸铅(PZT)陶瓷颗粒为功能相,运用流延工艺制备了0-3型压电复合薄膜,研究了碳纳米管改性对0-3型压电复合薄膜综合性能的影响.结果表明:适量碳纳米管的掺杂不仅可以提高PVDF基体的介电常数,还可以导致具有压电性的β相基体的形成,以上两个效应均导致了0-3型压电复合薄膜压电性能的提高.     

聚偏氟乙烯压电纤维的制备工艺及其压电特性研究进展

聚偏氟乙烯（PVDF）是一种压电性能优异的聚合物，具有耐化学腐蚀性、耐磨性、高介电强度等优点。不同于常见的PVDF压电薄膜类产品，PVDF压电纤维具有灵敏度高等独到优势。本文介绍了PVDF的压电机理，综述了近年来国内外学者在利用各种纺丝法制备PVDF压电纤维时，通过改变纺丝方法、纺丝参数、纺丝添加剂及后处理条件，提高PVDF纤维的压电性能。     

微圆顶阵列结构柔性触觉传感器设计与应用研究

以质量分数3%和2%的炭黑/碳纳米管填充硅橡胶为力敏复合导电材料,提出了一种微圆顶阵列结构的柔性触觉传感器。阐述了微圆顶阵列结构触觉传感器的结构特点、制备流程及微观表征,并结合ANSYS有限元分析软件分析其触觉感知机理。研究该微圆顶阵列结构柔性触觉传感单元的力敏特性,并将其应用于足底压力分布感知。测试结果表明,该微圆顶阵列结构柔性触觉传感器具备良好的力敏特性和穿戴舒适性,为柔性可穿戴触觉传感器提供了一种设计方案。     

基于认知图的机器人触觉传感服装数据处理

应用归一化转动惯量特征识别方法，对作用于服装的接触物进行形体重建，建立了机器人服装触觉传感数据处理的认知图模型，给出了相应的推理运算步骤.认知图概念节点的输入量包括压力位置、大小等服装传感数据及识别重建后的接触物形体.输入数据后，通过对认知图的运算确定机器人对接触物刺激的反应行为.由于机器人触觉传感服装数据的结构化程度较高，机器人对传感服装感知过程的各种要素存在着较明显的因果关系.实验结果表明，认知图可作为一种计算平台，适于机器人服装感知全过程的数据处理.     

柔性压电式微位移机构在精密机床定位中的应用研究

研究、设计了一种柔性压电式微定位机构。此机构采用压电陶瓷作为微位移驱动器,柔性铰链为导向机构,对丝杠螺母传动的精密机床工作台的运动位置进行自动补偿,实现了超精密定位。文中对柔性铰链机构进行了合理的设计及参数分析,并应用于精密机床中进行定位精度测试。实测结果表明,采用柔性压电式微位移机对精密机床工作台二次精定位,可使工作台定位精度提高到0.01μm,可满足精密、超精密加工需要。     

高柔弹性电子皮肤压力触觉传感器的研究

为解决可用于机器人等复杂三维载体表面的电子皮肤触觉传感器难以兼具高柔弹性及压力检测功能的难题,从材料的选取、结构的优化以及新型制作工艺等方面进行了研究,提出研制高弹性的柔性电子皮肤压力触觉传感器新方法. 采用新型银纳米线（AgNWs）/聚二甲基硅氧烷（PDMS）复合材料,基于半圆与圆形相结合的高柔弹性导电薄膜电极层及阵列式“多孔PDMS”的新型“三明治”式传感器阵列结构,极大地提高了触觉传感器的柔弹性,用模具固化成型工艺制作了高柔弹性电子皮肤压力触觉传感器. 结果表明:这种电子皮肤压力触觉传感器具有良好的柔弹性,其弹性拉伸率超越人类皮肤的弹性,达到了30%,可覆盖于机器人等复杂三维载体表面；在不同载荷条件下进行了压力大小及分布情况的测量,发现在自然及拉伸状态下,该电子皮肤压力触觉传感器均具有较高的线性度、灵敏度及较小的迟滞误差. 研究结果为机器人触觉感知技术和智能化发展奠定了基础.     

基于压电薄膜传感器的机器人触觉识别系统

为了使机器人通过触觉感知外部环境信息,弥补视听交互信息缺失的不足,根据聚偏氟乙烯（PVDF）材料的压电效应设计开发基于触觉传感器和卷积神经网络的机器人触觉识别系统,能够根据所采集的触觉信号识别出材质类型. 提出基于渐进式级联卷积神经网络的触觉识别算法. 该算法基于卷积神经网络提取机器人传感器的信号特征,包括经过短时傅里叶变换的触觉数据频谱图和信号表征周期内的时域特征. 为了解决特定材质识别混淆的问题,利用K-Medoids聚类算法和动态时间规整（DTW）距离度量算法将分类过程区分为粗、细2个层次,构建渐进式分类模型. 实验表明,设计的触觉传感器对物体材质的平均识别正确率约为97%,机器人能够成功识别触摸到的真实材质,为下一步的探索交互任务奠定基础.     

Low frequency wide bandwidth MEMS energy harvester based on spiral-shaped PVDF cantilever

In this paper,a piezoelectric energy harvester based on spiral-shaped polyvinylidene fluoride(PVDF)cantilever is designed and fabricated for harvesting low frequency vibration energy in the environment.In this design,the spiral-shaped PVDF cantilever is major for lowering the resonant frequency by increasing the length of the cantilever;Copper and silicon proof masses on both sides are working on further decreasing the resonant frequency and widen its bandwidth.Due to the high flexibility of the PVDF cantilever,this device is extremely sensitive to vibration and can harvest weak vibration energy.Both simulation and experimental results have approved that this device can operate at very low frequency which is about 20 Hz and can effectively harvest energy from 15–50 Hz.The peak of the output voltage can reach 1.8 V with the acceleration of 0.2 g.This is a promising harvester for powering the wireless sensors in the future.     

Investigation and characterization of an arc-shaped piezoelectric generator

novel arc-shaped piezoelectric generator based on flexible PVDF thin film is presented and systemically studied. With a periodical external force, the generator can produce peak voltage of 45.6 V and peak power of 30.7 μW. The maximum power density reaches 38.4 μW/cm³ with a 4 cm × 2 cm × 100 μm device, at the optimum load resistance of 33.33 MOhm. The influence of frequency, size dimension and load resistance are investigated through experimental measurements. With this high output arc-shaped generator, capacitors can be effectively charged and three commercial LEDs have been directly lighted without any energy storage unit.     

利用压电自敏感致动器实现挠性结构振动的主动控制

以粘贴有压电自敏感致动器的挠性梁振动主动控制为例,论述了进行挠性结构传感器／致动器及控制系统一体化研究的方法。文中给出了压电自敏感致动器的电路模型及自敏感致动器的应变测量和应变速度测量电路,推导了测量公式。以玻璃钢材料的挠性梁为实验对象,采用自适应滤波技术来实现振动主动控制。控制系统由ＴＭＳ３２０Ｃ２５及４８６计算机组成的主从机系统实现。实验结果表明此种控制方法是有效的。     

PLZT/PVDF层合柔性悬臂梁的驱动特性

为了实现光驱动柔性悬臂梁结构同时具备远程可控和快速驱动的特性,提出基于0-1极化的光电陶瓷PLZT与压电薄膜PVDF的光电/压电复合驱动柔性梁结构,研究该结构的驱动特性.在PLZT/PVDF复合驱动器数学模型的基础上,构建PLZT/PVDF层合柔性悬臂梁的数学模型.对PLZT/PVDF层合柔性悬臂梁驱动特性的影响因素进行理论分析,简化层合悬臂梁的挠度方程.通过实验对PLZT/PVDF层合柔性悬臂梁的数学模型进行参数识别,给出层合梁挠度幅值变化的理论曲线.实验显示,理论值与实验值的相对误差小于4%,表明利用所构建的PLZT/PVDF层合柔性悬臂梁数学模型能够较准确地反映层合柔性悬臂梁的驱动特性.结果表明,随着PVDF长度的增加,层合悬臂梁挠度幅值先增大后减小;层合悬臂梁挠度幅值随着PVDF厚度的增加而增大.     

Electromechanical coupling properties of a self-powered vibration sensing device for near-surface observation tower monitoring

The wind-induced vibration of a remote sensing tower is the key factor affecting the stability of image sensing and structural reliability. Monitoring the vibration of a long-time unattended tower is critical to its proper operation. Currently, most monitoring devices are supplied with wired power or battery, significantly limiting their practical applications in remote areas. In this paper, a self-powered vibration sensing device based on hybrid electromechanical conversion mechanisms is proposed. The device depends on a cylindrical magnetic levitation structure sensitive to ambient vibration for transferring mechanical energy and takes as a dual-functional heterogeneous integrated system comprising electromagnetic, piezoelectric, and triboelectric generators. When the device vibrates under environmental force driving, the suspension magnet reciprocates vertically and generates induced electromagnetic energy, which is used to power the device. Moreover, the triboelectric and piezoelectric voltages, respectively originating from magnet impact on two separation friction materials and magnetic field repulsion-induced strain deformation of a piezoelectric sheet, are used as the synergistic sensing signals. To improve the output energy, a set of dual-segmented annular coils is designed in an electromagnetic generator, which greatly avoids the obstructive effect of the suspended magnet on the magnetic flux change at its end. Compared with a whole isochoric coil, it increases the output voltage by 78.3%. For the triboelectric sensing module, a silicone film with a large specific surface area is fabricated via 3D modification, which improves the output voltage by 29.4%. Furthermore, a pair of piezoelectric sensing modules is set to improve the accuracy of comparative sensing data. The experimental measurement shows that the device maintains a high sensitivity of 6.711 V (m s^?2)^?1 and excellent linearity of 0.991 in the range of 0–14 m s^?2. This work provides a practical strategy for the vibration monitoring of remote sensing tower and exhibits attractive potential in early warning and data analysis.

     

Composite Polymer Electrolyte Membranes based on Nafion and Modified PVDF Electrospun Nanofiber Mats

We fabricated the nanofiber composite membranes by impregnating Nafion into the modified polyvinylidene fluoride(PVDF) electrospinning nanofiber mat for proton exchange membrane fuel cells applications.The hydrophobic PVDF nanofibers mat became to the hydrophilic state by alkali treatment for the full embedding of Nafion into the PVDF network.The fabricated composite membranes exhibit significantly enhanced thermal stabilities,swelling resistance,and observably improved mechanical property compared to the pristine Nafion membrane.When the content of PVDF nanofiber mat is 15.1wt% in the membrane,the proton conductivity of the nanofiber composite membrane is nearly equal to that of pristine Nafion membrane with the same condition.The experimental results show that the prepared composite membrane can be used as a promising polyelectrolyte membrane for fuel cell applications.     

Study on performance of PVDF piezoelectric film for the separator in Li-ion rechargeable cell

The properties of piezoelectric PVDF films as separators are studied in NiO/Li electrodes Li-ion power cell. The results show that the PVDF piezoelectric film with excellent insulation is suitable for the environmental energy harvesting application. This is attributable to the compact structure of the piezoelectric PVDF film, and which make it has low leakage current and low charge-discharge current characteristics.     

A Six DOF Compliant Force/Torque Sensor

INTRODUCTION~ManyrohotictasksreqUirelocalsensingandrePOsitioningofthetoolbeingused.FOrexample,amanworkingwithahandgrinderordehutringtoolreliesontheforcefeedbackfromhiswristtogUidethetool~undthevaryingcontoursofthecomPOnentbeingworkedon.Inaddition,headjuststLhestiffnessofhisarmsandaeststosuitthedynamiccharacteristicsoftLhetask.ThecompliantF/Tsensordescribedinthispaperistoemulatesuchabilities.Ontheonehand,itscompliancecanabsorbthepositioningermrOftherobotsothatthesensorcanprotectthetoo…     

U形直线超声电机结构设计

针对直线超声电机的小型化问题,提出一种新型U形直线超声电机,该电机由U形定子和导轨组成,压电陶瓷片采用粘贴的方式固定在定子上.研究了电机的激振方式与位置,设计并加工了直线超声电机样机和测试装置.将柔性铰链结构应用到直线超声电机夹持中.通过实验确定了电机的最佳工作频率、预压力.研究了输出力和空载速度随工作频率、预压力和电压的变化规律.实验表明,电机在电压值400 Vpp,预压力25N条件下,最大空载速度470 mm/s,最大输出力9N,定子质量25 g,推重比达36;柔性夹持能提高电机的模态一致性和效率,同时简化了电机结构.该研究为电机小型化发展奠定基础.