一种非硅微加工技术制作的电热微驱动器

介绍了一种由非硅微加工技术制作的电热微驱动器。基于双金属效应,采用聚合物SU-8胶和金属镍作为功能材料和结构材料,铜为牺牲层材料制作电热微驱动器。利用ANSYS有限元分析软件进行仿真,模拟驱动位移随加热时间的变化关系,并由此得出驱动力的大小,比较结果后确定结构参数。再通过光刻、掩模电镀和牺牲层刻蚀等工艺,加工制作出了电热微驱动器样品,并对样品进行了观测和分析。     

仿昆扑翼微飞行器电磁驱动电路设计与制造

针对电磁驱动方式的仿昆扑翼微飞行器,设计了电磁线圈驱动电路,电路能够驱动微飞行器扑动双翼。驱动电路利用电池组和升压(BOOST)电路实现电路供电。研制了产生两路电压控制信号的最小系统板,能够在上位机在线实时控制输出信号的频率和幅值。电压控制信号通过电路后,电路输出稳定驱动电流,实现对仿昆扑翼微飞行器翅膀的控制。     

毫米级静电微扑翼驱动器的结构设计、工艺与测试

针对仿昆虫扑翼飞行器核心动力装置——微驱动器的结构特点和研究难点,设计了一种基于静电驱动原理的毫米(mm)级微扑翼驱动器,并针对各个部件研究了整套加工工艺与测试方法.运动优化与升力测试结果表明:微扑翼驱动器(翼展9 mm,重量3 mg)以91 Hz的频率实现了±40°的拍动和±25°的扭转运动,输出1.5 mg的升力,升重较以往静电微扑翼驱动器有大幅提升.研究成果为实现仿昆虫微型飞行器的自主飞行提供了新的方向,并奠定了理论与试验基础.     

Design and fabrication of twisted monolithic dielectric elastomer actuator

This paper presents a novel design of dielectric elastomer actuator (DEA), called single body dielectric elastomer actuator (SDEA), to improve the performance of existing DEAs. The DEA is typically configured with stacking multiple dielectric elastomer film and linearly contracted according to the applied voltage. SDEA is fabricated monolithically without external frame and has the advantages of flexibility and light weight. Thus, it is applicable to various configurations of actuators such as twisting or bending, etc. By exploiting the advantages of SDEA, we propose a new 2-ply design of SDEA. The design is configured with plying couples of monolithically fabricated SDEA. We explain how it can amplify the stroke with its basic principles of operations. In addition, its fabrication method is addressed. Finally, the results of performance evaluations are included with respect to stroke, force, speed, etc.     

基于电磁驱动的微扑翼飞行器驱动器振动特性

电磁驱动的微扑翼飞行器翼端拍打振幅受到驱动电压、磁感应强度、电流角频率等因素的影响。为了探究上述三个因素对微扑翼飞行器翼端拍打振幅的影响规律,提出一种新型电磁驱动器方案,并建立电磁场中微梁振动模型,为验证电磁驱动器方案的可行性及进一步探究相关因素对微梁振动的影响规律,设计开展电磁驱动的微梁振动试验。结合理论振动模型与试验结果,得到驱动电压、磁感应强度、电流角频率对于梁端拍打振幅的影响规律,研究结果对于后续微扑翼飞行器电磁驱动器的研究发展具有一定的指导意义。     

The design and simulation of a novel out-of-plane micro electrostatic actuator

This paper presents a mechanism of developing a novel out-of-plane micro electrostatic actuator capable of causing large out-of-plane deflection. The performance of the actuator is evaluated and simulated by MEMCAD software. Initial analysis results indicated that the usage of both the novel U-shape suspension beam and the electrostatic actuation mechanism permit large rotations motion with respect to the increment of the numbers of electrodes. Moreover, stable rotational motion can be achieved by varying the dimensions of electrode and gap spacing. This design advantage brings the possibility of developing other three-dimensional (3D) structures for on and/or out-of-wafer applications such as optical switch or display.     

Hybrid micro electrostatic actuator

A hybrid micro-electrostatic actuator is presented. The actuator integrates a vertical comb driving (VCD) unit and a parallel-plate driving (PPD) unit. The hybrid actuator is fabricated using a one structural layer microfabrication process, i.e., MetalMUMPs instead of a two-layer microfabrication process needed for traditional vertical comb-drive actuators by taking advantage of the residual stress gradient in the MetalMUMPs nickel layer, which raises the moving parts of the actuator above the substrate after release. The hybrid actuator significantly simplifies the fabrication process for vertical comb-drive actuators, i.e., turning a process requiring two structural layers into a process requiring only one structural layer and thus avoids any misalignment between the two layers. The hybrid actuator can generate larger force and then a larger displacement than the actuator having only the VCD with the same area since no extra space is needed for the PPD unit which uses the moving electrode existing in the VCD unit and a fixed electrode under the VCD unit. The VCD and PPD units in the hybrid actuator are subject to the same driving voltage and work together to pull the moving parts of the actuator downward. A model is established for the hybrid actuator to analyze its displacement. The analytical results show that displacement of the moving part of the hybrid actuator is about half of the gap between the electrodes of the PPD unit. Prototypes are fabricated and tested. With a driving voltage of 150 V, the hybrid actuator achieved a measured displacement of 6.48 µm.     

Design,fabrication and testing of a novel symmetrical 3-DOF large-stroke parallel micro/nano-positioning stage

Limited travel stroke constrains the application of existing XYZ parallel micro/nano-positioning stages. In this paper, a novel parallel-kinematic symmetrical micro/nano-positioning stage is proposed to enlarge the travel range with a compact physical size. For a large-stroke parallel stage, the cross-axis motion increases the difficulty of closed-loop control process. The motions of the parallel stage on different axes are decoupled by employing I-shaped flexure hinges in this work. In order to obtain a large input displacement for actuating the stage, three voice coil motors (VCM) are adopted. In view of the lower output force of the VCM, the guiding flexure mechanism is designed with an optimized cross-sectional dimension. To verify the performance of the stage, analytical modeling and simulation study are carried out. A prototype stage is fabricated for experimental studies. Results show that the designed parallel micro/nano-positioning stage owns a three-degree-of-freedom motion workspace of 2.22 mm × 2.22 mm × 1.81 mm with an overall size of 176 mm × 176 mm × 198 mm, which is more compact than existing symmetrical designs containing the actuators. Moreover, the symmetrical design enables a low crosstalk of 1.7% among the three working axes.     

Design and fabrication of a cross flow micro heat exchanger

A cross flow micro heat exchanger was designed to maximize heat transfer from a liquid (water-glycol) to a gas (air) for a given frontal area while holding pressure drop across the heat exchanger of each fluid to values characteristic of conventional scale heat exchangers. The predicted performance for these plastic, ceramic, and aluminum micro heat exchangers are compared with each other and to current innovative car radiators. The cross flow micro heat exchanger can transfer more heat/volume or mass than existing heat exchangers within the context of the design constraints specified. This can be important in a wide range of applications (automotive, home heating, and aerospace). The heat exchanger was fabricated by aligning and then bonding together two identical plastic parts that had been molded using the LIGA process. After the heat exchanger was assembled, liquid was pumped through the heat exchanger, and minimal leakage was observed     

Design and manufacturing of mobile micro manipulation system with a compliant piezoelectric actuator based micro gripper

This paper presents a new design of mobile micro manipulation system for robotic micro assembly where a compliant piezoelectric actuator based micro gripper is designed for handling the miniature parts and compensation of misalignment during peg-in-hole assembly is done because piezoelectric actuator has capability of producing the displacement in micron range and generates high force instantaneously. This adjusts the misalignment of peg during robotic micro assembly. The throughput/speed of mobile micro manipulation system is found for picking and placing the peg from one hole to next hole position. An analysis of piezoelectric actuator based micro gripper has been carried out where voltage is controlled through a proportional-derivative (PD) controller. By developing a prototype, it is demonstrated that compliant piezoelectric actuator based micro gripper is capable of handling the peg-in-hole assembly task in a mobile micro manipulation system.     

Design and modeling of electromagnetic actuator in mems-based valveless impedance pump

This study models and optimizes the electromagnetic actuator in an MEMS-based valveless impedance pump. The actuator comprises an electroplated permanent magnet mounted on a flexible PDMS diaphragm and electroplated Cu coils located on a glass substrate. In optimizing the design of the actuator, the objective is to maximize the output flow rate of the micropump while maintaining the mechanical integrity of its constituent parts. The study commences by developing optimized theoretical models for each of the components within the actuator, namely the diaphragm, the magnet, and the micro-coils. The theoretical models are then verified numerically using FEA software. The magnitude of the magnetic force acting on the flexible diaphragm is calculated using Ansoft/Maxwell3D FEA software. The simulation results obtained by ANSYS FEA software for the diaphragm deflection are found to be in good agreement with the theoretical predictions. In general, the results show that the desired diaphragm deflection of 15 μm can be obtained by passing a current of 0.6–0.7 A through the micro-coil to produce a compression force of 11 μN. The valveless micro impedance pump proposed in this study is easily fabricated and is readily integrated with existing biomedical chips due to its plane structure. The results of this study provide a valuable contribution to the ongoing development of Lab-on-a Chip systems.     

Analysis and fabrication of a novel MEMS pendulum angular accelerometer with electrostatic actuator feedback

A new type of sensor to directly detect angular acceleration is essential for inertial and control technology. The above interest motivates us to propose a novel micro electromechanical system (MEMS) pendulum angular accelerometer with electrostatic actuator feedback. It adopts a proof pendulum with optimized moment of inertia, suspended to dual anchors by a pair of torsion spring beams, as sensing component. A pair of electrodes are designed as differential capacitors to detect the torsional angular of pendulum, then measure input angular acceleration in sensing axis. Another pair of electrodes are designed as electrostatic actuators for feedback control loop. The structure and operating principle of the MEMS angular accelerometer are introduced. Then, the structure kinetics analysis and signal detecting scheme based on differential capacitors are provided in detail, and the sensitivity and resolution of sensor are derived. Compared with the other MEMS angular accelerometers, the proof pendulum with optimized moment of inertia improves sensitivity and resolution of sensor. The electrostatic actuators feedback loop optimizes the dynamic capability and nonlinearity characteristic. The sensor is fabricated by MEMS fabrication technology. The ANSYS simulation and test results prove the validity of the theoretical analyses. The MEMS angular accelerometer can be used in industrial robots and aircraft by further implementing the signal processing electrocircuit.     

Rotational micro actuator for microsurgery

In this paper an innovative hydrostatic micro actuator system for controlling the rotational degree of freedom of microsurgery instruments is presented. From the possible hydrostatic motor designs, an annular gear motor in orbit configuration has been chosen based on its suitability for micro manufacturing. The innovative actuator design includes a rotor-integrated control mechanism for connecting the actuator’s individual positive-displacement chambers. First a macro-model of the new actuator was fabricated and tested. The obtained test results already confirm the functionality and show the actuator’s exciting potential. The important design parameters were identified and a mathematical model was developed and is presented in this paper. Thereby optimized design parameters enable a further miniaturization and the use within minimal invasive surgery tools. A potential application of this novel device is discussed in the context of endovascular and interventional resection treatment. Combined with a shape memory alloy actuator a tool for the resection of calcified aortic valves was developed. Because of its small size it is possible to integrate it into a trocar channel.     

Design of swing arm type actuator and suspension for micro optical disk drive

One of the trends on information storage device is focused on the development of micro-optical devices with optical flying head (OFH). Many different types of sliders for OFH and optical component systems have been introduced in the literature. However, the important issues on the mechanical system, which consists of suspension, swing arm and voice coil motor (VCM) part has not been discussed up to date. In this research, a swing arm type actuator with suspension for micro optical disk drive is designed and developed, basically focused on the mechanical issues, which should be solved for real application.     

Design and fabrication of a novel microfluidic nanoprobe

The design and fabrication of a novel microfluidic nanoprobe system are presented. The nanoprobe consists of cantilevered ultrasharp volcano-like tips, with microfluidic capabilities consisting of microchannels connected to an on-chip reservoir. The chip possesses additional connection capabilities to a remote reservoir. The fabrication uses standard surface micromachining techniques and materials. Bulk micromachining is employed for chip release. The microchannels are fabricated in silicon nitride by a new methodology, based on edge underetching of a sacrificial layer, bird's beak oxidation for mechanically closing the edges, and deposition of a sealing layer. The design and integration of various elements of the system and their fabrication are discussed. The system is conceived mainly to work as a "nanofountain pen", i.e., a continuously writing upgrade of the dip-pen nanolithography approach. Moreover, the new chip shows a much larger applicability area in fields such as electrochemical nanoprobes, nanoprobe-based etching, build-up tools for nanofabrication, or a probe for materials interactive analysis. Preliminary tests for writing and imaging with the new device were performed. These tests illustrate the capabilities of the new device and demonstrate possible directions for improvement.     

Design and fabrication of an on-chip micro flow cytometer with integrated micro-lens

Microsystem Technologies - In this paper, the design and fabrication of an on-chip micro flow cytometer chip with integrated micro-lens with a size of...     

Design, fabrication, and control of MEMS-based actuator arrays for air-flow distributed micromanipulation

This paper reports the design, fabrication and control of arrayed microelectromechanical systems (MEMS)-based actuators for distributed micromanipulation by generation and control of an air-flow force field. The authors present an original design of pneumatic microactuator, improving reliability and durability of a distributed planar micromanipulator described in the previous study. The fabrication process is based on silicon-on-insulator (SOI) wafer and HF (hydroflouric acid) vapor release, which also significantly increases the production yield of the 560 microactuator array device of 35/spl times/35 mm/sup 2/. Minimization of the electrostatic actuation pull-in voltage through suspension shaping fabrication was also studied, and successfully validated for electrical efficiency improvement. A distributed control method to achieve good conveyance performance and reduce motion control instability was investigated. An emulation approach was chosen to validate a decentralized control strategy on the distributed active surface in order to conduct a proof-of-concept of a future smart structure, integrating sensors, intelligence, and microactuators. Thus, a centralized/decentralized control flow, inspired by autonomous mobile robot principles, was applied. It was modeled and implemented using C-programming language. Experimental and characterization results validate the control method for feedback micromanipulation with good velocity and load capacity performance.     

Design and testing of a microgripper with SMA actuator for manipulation of micro components

The extremely high work-to-volume ratios of the SMA actuators make them suitable to be used as a powerful actuator in micro-scale manipulation. In this study, an easily manufacturable micro-gripper with shape memory alloy (SMA) wire actuator was designed and manufactured. The concept of the designed micro-gripper was based on flexible hinge structures to increase the deflection efficiency and strength. The size of microgripper was a significant criterion in our design. Also, innovative layout in locating of SMA wire caused the microgripper to gripe and manipulate a boarder range of objects. The finite element method was used to analyze and calculate the stress distribution and jaw’s deflection in the gripper. In order to verify the modeling results, an experimental analysis by building a set-up for micro-gripper and running tests were implemented and it showed a good agreement with the modeling results. The approximate size of the micro-gripper is about 12 × 10 mm and its maximum achievable deflection is 200 μm which is perceptibly higher than SMA actuated micro-grippers with the same size.

     

Dynamic simulation and novel fabrication technique on ICPF-based micro-actuators for flexible micro dosing systems

Dynamic analysis of sandwiched driving diaphragms, made of ionic conductive polymer (ICP), and an innovative fabrication technique to micro-machine them are reported. Firstly, the dynamics of ICP film (ICPF) is theoretically studied and described by governing equations via chemical and mathematical analysis. The purpose to derive the governing equations is to explore the explicit relation of the induced lateral deflection of ICPF with respect to applied electrical field. This is the first major issue of this report. The other major issue is ICPF fabrication technology. The device structure of the micro pump unit, made of polydimethylsiloxane, and the sandwiched ICPF are successfully integrated as a monolithic driving module by the proposed innovative fabrication technique. From the viewpoint of mass production, there are three challenging targets to be achieved. First of all, the novel method to fabricate ICPF actuators is developed to overcome the conventional defect: insufficient adhesion of coated electrodes upon ICPF. Secondly, the ICPF has to be retained considerably right straight and flat as it is fabricated, even though its thickness is far less than its length. Lastly, the ICPF has to operate in aqueous environment. This has been fully taken into consideration by the proposed fabrication technique.     

Design and experiment of an electromagnetic levitation system for a micro mirror

In this paper, the design and characterization of a contactless electromagnetic levitation and electrostatic driven microsystem is presented, which has applications for example for large scale angle rotation micro mirrors. The proposed design can levitate a fabricated aluminum micro rotor which can incorporate a mirror and control it to rotate around the vertical axis within the range of ± 180°, which enlarges the scanning angle dramatically compared with conventional torsion micro mirrors. The rotation angle of the micro rotor is detected by the change of capacitance and controlled by the electrostatic force produced by variable capacitors. The levitation of the micro rotor is realized by utilizing electromagnetic inductions. The rotation is achieved through electrostatic forces generated by a digital controller. The hybrid system design for a micro rotor, combining magnetic and electrostatic forces is introduced. The digital control strategy is based on a PID controller with bias voltage. The detection interface circuit, which is based on frequency multiplexing, is also presented in this paper. It has been experimentally shown that the proposed design can levitate a 1.65 mm radius and 8 µm thickness aluminum micro rotor to 100 µm height with 20 MHz frequency and 0.5A p-p input current. Square and slope wave input experiments were carried out. The experimental results show that the control principal is in good agreement with the simulation models and this applies as well to the time-response performance and stability.