基于介电弹性体驱动的仿生象鼻软体驱动器设计分析

在软体机器人的发展过程中,软体驱动器结构简单化、轻量化设计一直是研究热点。受到象鼻结构与驱动原理的启发,设计了一种基于介电弹性体和多孔PDMS材料的仿生软体驱动器。首先对介电弹性体人工肌肉驱动机理进行了分析,并通过驱动变形实验确定了最大形变参数;然后设计了基于多孔PDMS材料的支撑脊柱结构,并通过压缩实验测试了力学性能;最后,通过将介电弹性体包覆在支撑脊柱外层,形成了具有圆柱结构的仿生软体驱动器。驱动实验结果表明,软体驱动器在电压激励下能够获得大角度(最大42°)连续稳定弯曲变形以及较快的响应速度。     

球壳形介电弹性体驱动器电致应变特性分析

介电弹性体是电场型电活性聚合物的一种,能够在外加电场的作用下,通过材料内部结构的改变发生伸缩、弯曲、束紧或膨胀等变形,人为控制电压的大小,精确控制变形.基于Neo-Hookean应变能模型,采用ABAQUS有限元软件,开展了材质为丙烯酸聚合物的球壳形介电弹性体驱动器在机电载荷作用下的力学性能有限元模拟,分别分析了无机械预拉伸和有机械预拉伸条件下电致应变特性,进行了球壳形介电弹性体驱动器机电耦合特性的有限元仿真分析,为球壳状介电弹性体驱动器的力电特性、变形失效、稳定性的进一步研究提供了一定的理论依据.     

介电弹性体线性驱动器研究

为满足未来机电系统对新型驱动器的需求,研究菱形介电弹性体线性驱动器。在分析驱动器工作原理的基础上,通过驱动器力—位移曲线和预载荷关系的分析,确定弹性预载荷元件。驱动器通电后能迅速响应,线性位移达到21 mm,弹性体面积变化率达到98%;驱动器失电后能迅速退回,最终退回到初始位置。通过试验分析电压和负载对驱动器的影响,试验表明：驱动器输出位移取决于电压;负载在驱动器输出力范围内对输出位移影响不大,但会影响其运动速度。并根据驱动器的特点,指出驱动器的应用范围。     

锥型介电弹性体驱动器的性能研究

介电弹性体驱动器在机器人系统、医疗机械系统以及智能驱动系统方面已经显示出广泛的应用潜能,具有结构简单、质量轻、能量密度大、效率高、变形大的优点.采用3M VHB4910介电弹性体设计并制作了锥型介电弹性体驱动器,并进行了锥型驱动器的驱动实验.测得锥型驱动器在一个通断电过程中的力一位移曲线,并计算得到驱动器的差力为1.65 N.实验结果表明锥型驱动器在通电后可以较大的线性位移,面积变化率为15.49%,断电后又能较快地恢复初始位置.同时对驱动器在一个工作周期中的做功进行分析,指出锥型驱动器可以通过多层薄膜的叠加来提高输出功.     

介电弹性体材料研究现状综述

针对目前介电弹性体材料的相关研究进展及存在的问题,在分析介电弹性体特性的基础上,根据其不同种类,研究了硅橡胶、聚氨酯、丙烯酸等材料及复合材料的性质及制备方法;根据介电弹性体的不同用途,分析了近些年其在发电、仿生学、生物医学、光学器件、微系统、航天航空方面的具体应用及其未来发展趋势,并总结了介电弹性体在未来应用中存在薄膜制备、柔性电极材料覆盖绝缘、偏置高压电源限制、降低能量损耗和提高机电转换效率等相关问题,针对这些问题提出了相应的建议及未来发展思路。研究结果表明,介电弹性体具有很广阔的应用前景,但是目前还存在很多技术难点,在弹性体基体材料构成、柔性电极材料优化、自偏置发电、效率优化等方面还要进行更为深入的研究。     

基于介电弹性体的旋转步进柔性驱动器

为了适应未来小型自动化机器的驱动需求,设计并实现了一种基于单层介电弹性体薄膜的旋转步进柔性驱动器。相对于传统双轴拉伸装置,自制的八爪拉伸装置使介电弹性体薄膜的预拉伸更均匀。测试了不同预拉伸量下介电弹性体驱动器的最大形变量,确定了制作驱动单元所需的介电弹性体薄膜最佳的预拉伸量。最终通过合理的设计将棘轮机构和驱动单元相结合实现了旋转步进柔性驱动。由于介电弹性体驱动器存在迟滞现象,导致驱动器的步进频率会随着负载质量的增大而减小。通过调节驱动信号的频率,可以改变驱动器的负载能力及步进频率。试验结果表明,当驱动电压为4.53 kV,空载时驱动器步进频率最高可达2.3 Hz;负载时,最大负载为263 g,即峰值扭矩为13.15 mN·m,此时步进频率降至0.22 Hz。     

介电弹性体摆动驱动器的分析与实现

根据介电弹性体摆动驱动器的工作原理,设计了摆动驱动器.通过对比试验得到性能较佳的摆动驱动器,该摆动驱动器的研究可为仿生机器人的驱动实现提供一种可能的解决方案.     

介电弹性体发电的基本原理及在分布式发电中的应用

论述介电弹性体发电的基本原理、目前的研究情况及应用前景.作为发电材料,介电弹性体与其他发电材料比较,其具有材料价格便宜、容易制造且质地柔顺,特别适合于诸如利用风及海浪等大动作进行发电的场合.     

介电型电活性聚合物圆柱形驱动器的驱动效率

研究了介电型电活性聚合物(DEAP)驱动器的机电能量转换机理、能量损耗和驱动效率。建立了驱动器机电能量转换模型,并通过试验测算了驱动器等效电路的模型参数,分析了电极材料等因素对DEAP相对介电常数的影响。深入研究了驱动器漏电流损耗,试验验证了漏电流对驱动器性能的影响。最后,设计了驱动器驱动试验台,完成了不同行程的准静态驱动试验,数值计算了驱动器的驱动效率。结果表明:由于等效电路电容未参与能量转换,驱动器机电转换效率分别为17.6%和25.6%。低电压、小行程驱动时,试验误差与理论分析误差不超过15%;而高电压、大行程驱动时,DEAP膜的漏电流等非线性因素使其驱动效率变化明显。该结果可为DEAP圆柱形驱动器的优化设计及合理使用提供指导。     

介电弹性体发电机机电转换的非线性方法研究

针对介电弹性体(DEG)研究中存在的效率瓶颈问题,对DEG机电能量转换方法进行了研究,提出了一种非线性DEG机电能量转换方法,并通过分析其基本机理,建立了非线性方法的理论模型和Matlab/Simulink仿真模型,对负载电阻值及翻转品质因子对机电转换效率的影响进行仿真。通过优化材料、机械传动结构、电路各元件参数配置及开关通断时间,提高了翻转品质因子Q,减少了电容电感串联形成电压翻转而造成的能量损失,进一步提高了机电效率。研究结果表明,通过对标准机电转换方法和非线性机电转换方法的比较,由于非线性转换环节的作用,使DEG两端电压的振幅大幅度提升,沿电压轴方向扩展了能量环,从而使DEG机电转换效率提高2.5倍;该研究结果对DEG的深入研究具有重要的意义。     

A tubular dielectric elastomer actuator: Fabrication, characterization and active vibration isolation

This contribution reviews the fabrication, characterization and active vibration isolation performance of a core-free rolled tubular dielectric elastomer (DE) actuator, which has been designed and developed by Danfoss PolyPower A/S. PolyPower DE material, PolyPower^TM, is produced in thin sheets of 80 μm thickness with corrugated metallic electrodes on both sides. Tubular actuators are manufactured by rolling the DE sheets in a cylindrical shape. The electromechanical characteristics of such actuators are modeled based on equilibrium pressure equation. The model is validated with experimental measurements from 3 actuators. The dynamic characteristics of three tubular actuators fabricated from the same batch of manufactured DE material are presented and compared to: (a) provide insight into the ability of the fabrication process to produce actuators with similar characteristics and (b) highlight the dominant dynamic characteristics of the core-free tubular actuator. It has been observed that all actuators have similar dynamic characteristics in a frequency range up to 1 kHz. A tubular actuator is then used to provide active vibration isolation (AVI) of a 250 g mass subject to shaker generated ‘ground vibration’. An adaptive feedforward control approach is used to achieve this. The tubular actuator is shown to provide excellent isolation against harmonic vibratory disturbances with attenuation of the resulting 5 and 10 Hz harmonics being 66 and 23 dB, respectively. AVI against a narrow band vibratory disturbance with frequency content 2–8 Hz, produced an attenuation of 20 dB across the frequency band.     

纯剪切模式介电弹性体发电机发电特性

为研究介电弹性体发电机的发电特性,基于COMSOL有限元软件建立了在纯剪切拉伸方式下的介电弹性体发电机有限元仿真机电耦合模型。该模型基于Yeoh超弹性材料本构,同时耦合发电机膜内静电力,根据可变电容理论对发电机电容变化及发电效果进行研究。设计了可Y向预拉伸的纯剪切拉伸装置,并在不同预拉伸条件下对发电机薄膜样本进行了拉伸实验,分析了其电容变化及发电效果。对比了仿真数据与实验结果,仿真模型的电容变化与实验测得的电容变化情况基本吻合,仿真模型一个周期内的输出电压变化与实验测得的电压变化基本吻合。实验及仿真结果表明,在相同的拉伸条件下,Y向预拉伸增大了初始电容及电容变化速率,且当Y向预拉伸λ=1时的上升电压为83V,而λ=2时的上升电压达到252V,改善了发电性能。本文提出的介电弹性体发电机新的研究方法为发电机样机设计提供了新的思路。     

MEMS magnetometer based on magnetorheological elastomer

To develop a simple and low-cost MEMS magnetometer, a novel sensor based on the magnetostrictive effect of magnetorheological elastomer is proposed. The micromechanical sensor consists of a silicon sensitivity diaphragm embedded with a piezoresistive Wheatstone bridge, and a magnetorheological elastomer layer attached on the sensitivity diaphragm. The interaction between the magnetic field and the elastomer generates a deflection of the sensitivity diaphragm, which changes the piezoresistance and unbalances a Wheatstone bridge. The experimental results show that the sensor has good linearity in the magnetic field range of 0-120 kA/m and the saturation magnetic field is ∼150 kA/m. This simple, low-cost, low-power sensor is easily integrated with electronic circuits using the MEMS processes.     

Performance Investigation of Cone Dielectric Elastomer Actuator Using Taguchi Method

Dielectric elastomer actuator (DEA) show promise for mechatronic applications due to the advantages of dielectric elastomer, such as lightweight, flexible, low cost, high strain, etc, and many configurations of DEAs have been demonstrated. As a kind of linear actuator, cone DEAs are studied in some laboratory prototypes due to easy manufacturing, however, their performance have not been exploited fully. Based on the working principle of DEA, a four-bar linkage mechanism is designed to provide negative stiffness preload, which can increase displacement output of actuator (outer diameter 100 mm) to 17 mm. Three cone actuating units are assembled in parallel to enhance the maximum force output to 5.07 N. Loading experiments of actuator in forward and backward strokes are performed, the experimental results show that backward stroke has stronger actuating capability than forward stroke, accordingly application of actuator is recommended. Four factors rather than applied voltage, i.e., number of actuating units, pre-stretch ratio, inner diameter, and outer diameter, are determined as influencing factors for Taguchi method. Then the performance objectives of actuator, i.e., displacement output, maximum force output, and maximum work in backward stroke, are investigated based on L9(34) Taguchi orthogonal design. The mean signal-to-noise (S/N) ratio based on the larger-the-better criterion is calculated according to the acquired displacement and force output. Analytical results show that outer diameter has the most significant influence on displacement output, and maximum force out and work output are influenced most by number of actuating units. Inner diameter also has an important effect on the performance objectives of actuator, while pre-stretch ratio has the least influence. The proposed performance investigation is helpful for the design and application of cone actuator in mechatronic system.     

全息方法制备嵌段式液晶弹性体

研究了热致收缩形变三嵌段式液晶(LC)弹性体薄膜的制备方法,分析和测试了薄膜的偏光特性和热致收缩率.采用全息曝光的方法一次性制备出具有栅状结构的热致液晶弹性体薄膜材料.在此基础上采用偏光显微镜(POM)、He-Ne激光器对弹性体薄膜的嵌段式栅状结构和偏光特性进行检测,并分析了薄膜弹性体偏光特性和液晶分子取向的关系,对该...     

介质反射光栅中多层膜计算的研究

介绍了采用增强透射矩阵进行计算的严格耦合波方法,将这种方法应用到介质反射光栅的多层膜计算中。通过与商用软件计算结果的对比,证明这种计算方法的计算结果是准确可信的。与已有的计算方法比较,该方法简化了介质反射光栅的计算工作。     

EDM混粉工作液国产化研究

利用国产铝粉作为混粉工作液的粉末添加剂,进行混粉电火花加工试验研究。结果表明,国产铝粉用于混粉电火花加工对于改善加工质量和提高加工效率都具有明显效果。     

A face robot actuated with artificial muscle based on dielectric elastomer

Face robots capable of expressing their emotional status, can be adopted as an efficient tool for friendly communication between the human and the machine In this paper, we present a face robot actuated with artificial muscle based on dielectric elastomer By exploiting the properties of dielectric elastomer, it is possible to actuate the covering skin, eyes as well as provide human-like expressivity without employing complicated mechanisms The robot is driven by seven actuator modules such eye, eyebrow, eyelid, brow, cheek, jaw and neck module corresponding to movements of facial muscles Although they are only part of the whole set of facial motions, our approach is sufficient to generate six fundamental facial expressions such as surprise, fear, angry, disgust, sadness, and happiness In the robot, each module communicates with the others via CAN communication protocol and according to the desired emotional expressions, the facial motions are generated by combining the motions of each actuator module A prototype of the robot has been developed and several experiments have been conducted to validate its feasibility