电容式压力传感器的厚膜集成化研究

采用厚膜传感技术研制电容式感压元件,并通过厚膜混合集成技术将信号处理电路集成在感压元件上成为一体,进行电容式压力传感器的厚膜集成化研究。结果表明：研制成的新型厚膜电容式集成压力传感器,线性达到0．5％,迟滞小于0．5％,具有重复性好,受分布电容,寄生电容影响小,精度高,抗过载,耐腐蚀等特点,对厚膜感压元件,信号处理电路的设计与平面化加工以及集成化等进行了介绍,并对集成化中相关工艺,兼容性及性能进行了讨论。     

应用人工肌肉IPMC材料的三指微型柔性手爪设计

为满足现代小型驱动器的微型化、智能化、多功能及高集成度等要求,利用一种智能材料即离子聚合物金属复合物(ionic polymer-metal composite,简称IPMC)研制了一款三指微型柔性手爪。运用ANSYS有限元分析软件,通过等效压电双晶片的机电耦合模型对IPMC驱动元件进行有限元位移仿真,得到其在3V电压下最大变形及相应的位移分布图。根据仿真结果,设计IPMC手爪的夹持机构,制备了体积不大于13.5 cm3的IPMC微型手爪。试验测试结果表明,在3 V直流电驱动下,IPMC驱动薄膜(总长度为19 mm,自由端长度为14 mm)的末端最大变形为22 mm(负向位移与正向位移的总和),其最大变形速度约为4.44 mm/s,总重量为1.033g的手爪可以抓取1.973g的物体,其手爪的推重比约为2,而材料(IPMC的总重量为0.177g)的推重比甚至大于11.5。此IPMC柔性手爪的性能满足低耗能的设计要求,具有结构简单、柔顺、安静、体积小和推重比大等特点,在微小型驱动领域具有较好的应用前景。     

离子聚合物金属复合材料电学性能研究

建立了电流测试平台,并对不同IPMC进行电流测试分析,为IPMC材料的改性提供依据。选用TBC0.5A02电流传感器设计电路,采用NI PCI-6024E数据采集卡,通过LabVIEW程序编写采集程序,并对采集到的电流传感器的输出信号进行处理。将固定电压施加在一系列固定的电阻上,从而建立电流传感器输出值和输入值的关系,实现实时测量流经IPMC的电流。通过比较商业膜基体IPMC、自制膜基体IPMC以及TEOS改性膜基体IPMC在不同正弦电压信号下的电流值,证明该测试系统是可行的。     

厚膜静液挤压方法与工艺研究

本文研究了一种厚膜静液挤压方法．该方法通过最大限度地减少压力介质的使用量，解决了静液挤压中出现的蠕动问题，为此，专门研究了厚膜挤压用压力介质、组合模具等。通过改装的挤压机进行了Zr基非晶材料挤压。试验结果表明，挤压变形速率可控制0．5mm／s，挤压过程压力平稳，非晶材料变形均匀，没有出现断裂、晶化现象，证明厚膜静液挤压工艺的可行性。     

基于目标跟踪的IPMC测控系统设计

针对IPMC驱动和性能测试的需求,设计了一种IPMC测控系统。控制系统以STM32F103RET6为主控芯片,可输出双极性大电流的正弦波、方波和组合波形,并且输出信号的幅值、频率和占空比可调;位移检测系统基于Lab VIEW的MeanShift目标跟踪算法,可对IPMC末端进行目标跟踪,并实时显示其在两个方向上的位移。利用该测控系统进行IPMC性能测试实验,验证了其可行性。     

往复运动条件下润滑油膜特性的实验观察

采用多光束干涉技术观察往复运动条件下润滑油膜的滑移及黏弹特性,研究振幅和频率对往复动态润滑弹流油膜的影响。结果表明:往复运动过程中,在特定时刻气穴的出现使油膜厚度逐渐减小,削弱了滑移程度;因润滑油的黏弹性而引起的运动滞后导致了油膜的非对称性;频率增大时,正行程末端时膜厚明显增大,油膜输送速度也随着增大;而负行程末端油膜受气穴的影响膜厚增大较慢;振幅(输入位移)增大时,正行程末端时油膜整体平移,而负行程末端入口凹陷呈现先变明显而后消失的现象。     

HOM系列高精度光学膜厚监控系统的研制

叙述了新研制的适用于 DWDM窄带滤光片成膜控制的高精度光学膜厚监控系统。该系统在光谱带宽 0 .1 nm条件下 ,暗噪声小于± 0 .0 0 5 % ,性能优于目前的报道。使用它已成功地实现了 1 0 0 GHz,5 0 GHz DWDM窄带滤光片全自动成膜监腔。由其派生出的HOM系列的其他类型光学膜厚监控系统 ,可适用于不同的优质膜的过程控制     

基于视觉的柔性结构振动测量及其控制

针对柔性结构振动测试及控制问题,提出采用机器视觉测量结构振动并进行反馈控制的方法。为保证闭环控制系统的实时性,需要解决视觉图像处理数据量大、处理耗时长的问题。采取运动跟踪方法选择图像感兴趣区域(re-gion of interest,简称ROI)以减少数据处理量,并采用快速中值滤波算法提高图像处理速度。为了提高处理精度、保证处理结果的准确性,试验比较了3种微分边缘检测算子,采用Roberts算子和极值法提取图像中柔性结构末端边缘信息,并利用Hough直线变换方法进行修正。基于末端中心振动的信息反馈进行柔性梁结构振动控制理论分析和试验研究。结果表明,所采用的图像处理方法满足精度和实时性的要求,并验证了基于视觉反馈振动控制的可行性。     

水基磁流体轴承的微观弹流润滑分析

采用多重网格法和多重网格积分法对水基磁流体润滑轴承进行弹流润滑分析,在雷诺方程中考虑了热、非牛顿、磁场和时变的影响,探讨了粗糙度因素对弹流润滑性能的影响。分析中对比了轴-轴承双面和轴承单面带有正弦粗糙度时的润滑膜膜厚和压力的分布,并研究了双面都带有粗糙度相位不同时润滑膜压力和膜厚的分布。数值分析结果表明,两个表面都存在相同的粗糙度时,在波峰相对处的膜厚更小,压力更大,在波谷相对处的膜厚更大,压力更小;随着一个表面的粗糙峰远离另一个表面的粗糙峰时,膜厚和压力波动减小,润滑膜的最小膜厚逐渐增大,最大压力逐渐减小,直到润滑膜的粗糙峰与粗糙谷相对时,膜厚和压力不在波动,最小膜厚达到最大,最大压力达到最小。然后当这个表面粗糙峰再继续接近下一个表面粗糙峰时,膜厚和压力的波动增大,润滑膜的最小膜厚又开始减小,最大压力又增大,直到润滑膜的粗糙峰与粗糙峰相对时,膜厚和压力波动最大,最小膜厚达到最小,最大压力达到最大。     

IPMC型柔顺手爪作动器的设计与性能测试

为克服传统手爪机构传动链多,耗能大,结构复杂等缺点,设计并制作了一种应用电致动智能材料(IPMC)的柔顺手爪。运用Pro/E软件设计IPMC手爪的主体结构,并分析其运动过程,最终装配完成IPMC手爪;运用激光位移传感器,精密电子秤和Canon相机测试了研制的4片IPMC驱动薄膜的末端位移,端部力和平均运动速度,并通过Labview测试系统对其进行采样和分析。实验结果表明:IPMC手爪驱动元件的角位移在3V电压激励下超过了180°(-3V电压下负向位移与+3V电压下正向位移之和);其末端位移大小为其自身(除固定部分外)总长;手爪驱动薄膜每片重量约为0.5mg,可抓握质量为1.6g左右的物体。该手爪结构简单、位移大、耗能低;同时,由于IPMC的柔顺特性,在抓取物体时它会贴附在其表面,而不破坏其表面精度。因此,这种手爪适用于抓取表面粗糙度要求高的物体。     

A study on the control of an IPMC actuator using an adaptive fuzzy algorithm

The Ionic Polymer Metal Composite (IPMC) is one of the electroactive polymers (EAP) that was shown to have potential application as an actuator. It bends by applying a low voltage current (1–3 V) to its surfaces when containing water. In this paper, the basic characteristics and the static & dynamic modeling of IPMC is discussed. In modeling and analysis, the equations of motion, which describe the total dynamics of the system, are driven. To control the position of the IPMC actuator, an adaptive fuzzy algorithm is used. IPMC is a time varying system because the some parameters vary with the passage of time. In this paper, the modeling and control of IPMC is introduced.     

泳动微机器人推进机理研究

研究了IPMC高分子材料驱动的仿生鱼型泳动微机器人,分析了IPMC材料的弯曲特性、主要研究问题以及鱼类波状运动的机理。该微机器人具有柔韧性好、低电压驱动、良好的响应性能等特点,因此在工业、医疗领域具有广阔的应用前景。     

Micromachined fragment capturer for biomedical applications

Due to changes in modern diet, a form of heart disease called chronic total occlusion has become a serious disease to be treated as an emergency. In this study, we propose a micromachined capturer that is designed and fabricated to collect plaque fragments generated during surgery to remove the thrombus. The fragment capturer consists of a plastic body made by rapid prototyping, SU-8 mesh structures using MEMS techniques, and ionic polymer metal composite (IPMC) actuators. An array of IPMC actuators combined with the SU-8 net structure was optimized to effectively collect plaque fragments. The evaporation of solvent through the actuator's surface was prevented using a coating of SU-8 and polydimethylsiloxane thin film on the actuator. This approach improved the available operating time of the IPMC, which primarily depends on solvent loss. Our preliminary results demonstrate the possibility of using the capturer for biomedical applications.     

Identification of IPMC nonlinear model via single and multi-objective optimization algorithms

Ionic Polymer–Metal Composites (IPMCs) are electro-active polymers transforming mechanical forces into electric signals and vice versa. This paper proposes an improved electro-mechanical grey-box model for IPMC membrane working as actuator. In particular the IPMC nonlinearity has been characterized through experimentation and included within the electric model. Moreover identification of the model parameters has been performed via optimization algorithms using both single- and multi-objective formulation. Minimization was attained via the Nelder–Mead simplex and the Genetic Algorithms considering as cost functions the error between the experimental and modeled absorbed current and the error between experimental and modeled displacement. The obtained results for the different formulations have been then compared.     

离子交换聚合金属材料在匀速流中的传感实验研究

离子聚合物金属复合材料IPMC(Ion-exchange polymer metal composite,IPMC)具有驱动和传感功能。本文利用IPMC的传感能力，设计了一种海流速度信息传感器，基于3种模型分别使用ANSYS和MATLAB软件对不同条件的情况进行仿真，并设计测试系统进行实验，分析验证了片状IPMC在均匀流速下的传感能力。研究结果表明：片状IPMC的初始稳定电压以及测量灵敏度均与材料面积正相关；随着流速的增大，IPMC达到稳定输出电压的时间缩短，且材料输出电压在达到稳定前与时间呈现二次多项式函数关系，函数最大值即为实验所测得的稳定输出电压；各组次实验的重复性良好。     

直流电激励下的IPMC弯曲大变形力-电耦合模型

为了描述离子聚合物金属复合材料(ionic polymer metal composites, 简称IPMC)悬臂型驱动器在直流电激励下的非线性大变形行为,采用数字图像相关法(digital image correlation, 简称DIC)获得的IPMC应变梯度与激励电压间的关系,与修正后的IPMC电极分布式电阻电容（resistor-capacitor, 简称RC）电路模型相结合,提出了一种具有解析解的IPMC弯曲大变形力-电耦合模型,并采用Pt电极和Ag电极两种IPMC试样对该模型进行了实验验证。结果表明,该模型能够准确地反映IPMC悬臂型驱动器在直流电激励下的整体弯曲变形现象,且适用于采用沉积法制备电极的IPMC驱动器。     

Preparation and performance of soft actuator based on IPMC with silver electrodes

The surface electrodes of traditional ionic polymer-metal composites (IPMC) are made of platinum. To reduce the production cost, nonprecious metals such as silver is proposed. A new approach of electroless silver plating based on chemical deposition method is adopted, getting two types of IPMCs, Pt-Ag IPMC, and Ag-Ag IPMC. The microscopic analysis, driving abilities tests, and their surface-electrode resistance analysis show that Ag and Pt particles penetrate inside Nafion membrane with gradient distribution throughout the membrane. The maximum electro-active bending deformation angles of the specimens, which are obtained under the same specimen dimension and constrains, are about 60° for Pt-Pt IPMC and Pt-Ag IPMC and 90° for the Ag-Ag IPMC, respectively, corresponding to the driving voltage of 3 V, 4 V, and 1.5 V. The surface-electrode resistance of Ag-Ag IPMC is the lowest and the most stable, which shows that the proposed approach is valid. The experiments show that the IPMC technology based on the silver electrode is feasible.     

IPMC gripper static analysis based on finite element analysis

Recently, a type of flexible grippers with low power supply (0–5 V) has been designed and developed for grasping small but precision parts. In previous work, the authors manufactured a soft gripper whose actuating components are made of ionic polymer-metal composite (IPMC) materials; however, there is not a comprehensive model to analyze the complete mechanics for this IPMC gripper. Therefore, this paper provides a finite element method for analyzing its static mechanics characteristics in the state with maximal stress and strain (i.e., the gripper opening largest, including the IPMC deformation, stress, and strain). Further, these electromechanical coupling relationships can be simulated by using the piezoelectric analysis module based on ANSYS software. The simulation results show that the maximal tip displacement of IPMC strips can nearly reach their own free length, the maximal stress is 54 MPa in the center of copper electrodes, and the maximal strain is 0.0286 on the IPMC strip. The results provide detailed numerical solutions and appropriate finite element analysis methodologies beneficial for further research on the optimization design, forecast analysis, and control field.     

Modeling of bending behavior of IPMC beams using concentrated ion boundary layer

Ionic polymer metal composites (IPMCs) are an emerging class of electroactive polymers (EAP), which have many potential applications as sensors and actuators. Recently, IPMCs have been intensively studied because of their huge potential in medical, mechanical, electronic, and aerospace engineering. However, before the benefits of these materials can be effectively exploited for practical use, a mathematical model must be established to enhance understanding and predictability of IPMC actuation. The coupled electrical-chemical-mechanical response of an IPMC depends on the structure of the polyelectrolyte membrane, the morphology and conductivity of the metal electrodes, the cation properties, and the level of hydration. With this in mind, the purpose of this study is to establish a finite element model for bending behavior of IPMC beams. With reference to their operation principle, it is assumed that an IPMC beam has three virtual layers. We draw an analogy between thermal strain and real strain in IPMC due to volume change. This is a coupled structure/thermal model, and the finite element method is used to solve this model. The ion concentration distribution in the IPMC boundary layer is mimicked with the temperature distribution, and the electromechanical coupling coefficient is mimicked with the thermal expansion coefficient. Theoretical and experimental results demonstrate that our suggested model is practical and effective enough in predicting the blocking force of IPMC strips for different input voltages and strip thicknesses.