共查询到20条相似文献,搜索用时 15 毫秒
1.
Ki Bang Lee Young-Ho Cho 《Journal of microelectromechanical systems》2001,10(1):128-136
We present a new electrostatic actuation method using a lateral repulsive-force induced by an asymmetric distribution of planar electrostatic field. The lateral repulsive-force has been characterized by a simple analytical equation, derived from a finite element simulation. Quality-factors are estimated from the computer simulation based on creep flow model. A set of repulsive-force polycrystalline silicon microactuators has been designed and fabricated by a four-mask surface-micromachining process. Static and dynamic response of the fabricated microactuators has been measured at the atmospheric pressure for the driving voltage range of 0-140 V. The static displacement of 1.27 μm is obtained at the dc voltage of 140 V. The resonant frequency of the repulsive-force microactuator increases from 11.7 kHz to 12.7 kHz when the dc induction voltage increases from 60 V to 140 V. The measured quality-factors are increased from 12 to 13 in the voltage range of 60-140 V. Fundamental characteristics of the force, frequency and quality-factor of the electrostatic repulsive-force microactuator have been discussed and compared with those of the conventional electrostatic attractive-force microactuator 相似文献
2.
An electrothermally driven long stretch microdrive (LSMD) is presented for planar rectilinear motions in hundreds of micrometers. Design concept is based on connecting several actuation units in series to form a cascaded structure to accumulate relative displacement of each unit, and two cascaded structures are further arranged in parallel by a connection bar to double output force. The proposed area-saving design features monolithic compliant structure in compact arrangement to achieve long stroke. In experiments, the maximum reversible operating voltage is 3 V. In addition, the voltage-displacement relation shows good linearity within /spl plusmn/5% in 0.5-3.0 V. Fabricated nickel LSMD can generate displacement up to 215 /spl mu/m (W=8 /spl mu/m, /spl theta/=0.2/spl deg/, D=34 /spl mu/m) at 3 dc volts (669 mW). The maximum operation temperatures of tested LSMDs at 3 V are below 300 /spl deg/C. Output forces up to 495 /spl mu/N are measured by in situ passive micromechanical test beams. The LSMD can be operated at 100 Hz without degradation on displacement. Two geometrical design parameters, bent angle and constraint bar width, are also investigated analytically and experimentally. 相似文献
3.
A simple approach to characterizing the driving force of polysilicon laterally driven thermal microactuators 总被引:4,自引:0,他引:4
Based on the elastic analysis of structures, a simple approach to calculating the driving force for polysilicon laterally driven thermal microactuators is presented by using their deflection. The driving force obtained through the deflection is compared with available results measured by force testers fabricated on the same substrate as the microactuators. Reasonable agreement has been achieved. The approach allows one to predict the driving force for the microactuators as their deflection is designed. 相似文献
4.
Microsystem Technologies - Electrothermal microactuators possess a number of desirable attributes including ease of fabrication and large force and displacement capabilities relative to other types... 相似文献
5.
This research introduces a new type of data envelopment analysis (DEA) model termed the optimal system design (OSD) DEA model. Conventional DEA models evaluate DMUs’ performances given their known input and output data. The OSD DEA models take this one step further. They optimally design a DMU’s resource allocation in terms of profit maximization given the DMU’s total available budget. The need to design optimal systems is quite common and is sometimes necessary in practice. In actual fact, this study demonstrates that through the OSD DEA models, we can provide DMUs with more information than optimal portfolios of resources such as optimal budgets and budget congestion, i.e., the more the budget is consumed, the less the maximal profit. The proposed OSD DEA models are linear programs, and thus can be solved by the standard LP solvers to obtain DMUs’ optimal designs. However, to derive the DMUs’ corresponding optimal budgets, and to verify if the DMUs provide evidence of budget congestion, we need to modify the solvers, which may not be trivial. Therefore, this study exploits the special structures of the models to develop a simple solution method that can directly not only derive both a DMU’s optimal design and optimal budget, but can also check for the existence of budget congestion. 相似文献
6.
This paper presents a novel approach to verify and optimize surface micromachined electrothermal microactuators by using a
nodal analysis method. The nodal analysis method for the mechanical and electrostatic devices is a schematic-based method
which simplifies the design of MEMS devices significantly. A variety of the surface micromachined electrothermal microactuators
have been widely applied in various areas due to the high force provided at a relatively low input voltage. These electrothermal
microactuators can also be decomposed into essential elements of beams and anchors. This paper presents the nodal analysis
method for the electrothermal microactuators. The temperature dependent properties for the thermal conductivity, electrical
resistivity and thermal expansion coefficient of polysilicon beams are included. The effect of the effective axial length
for the beams due to lateral deflection and large axial stress is also taken into account. This approach is verified by ANSYS
and the simulation data agrees well with each other. It extends the general nodal analyses method to simulate the electrothermal
microactuators. 相似文献
7.
Microsystem Technologies - This paper presents a comprehensive modal analysis of Z-shaped beam electrothermal microactuators for the first time. Both longitudinal and lateral vibrations are taken... 相似文献
8.
9.
A common design of piezoelectric microactuators adopts a membrane structure that consists of a base silicon diaphragm, a layer of bottom electrode, a layer of piezoelectric thin film, and a layer of top electrode. In particular, the piezoelectric thin film is often made of lead-zirconate-titanate (PZT) for its high piezoelectric constants. When driven electrically, the PZT thin film extends or contracts flexing the membrane and generating an out-of-plane displacement. Many manufacturing defects, however, could significantly reduce the designed actuator displacement. Examples include residual stresses, warping, non-uniform etching of the silicon diaphragm, and misalignment between the top electrode and the silicon diaphragm. The purpose of this paper is to develop a dual top-electrode design to enhance the actuator displacement. In this design, the top electrode consists of two disconnected (thus independent) electrode areas, while a continuous bottom electrode serves as the ground. The two top electrodes are located in two regions with opposite curvature when the diaphragm deflects. When the two top electrodes are driven in an out-of-phase manner, the actuator displacement is enhanced. Finite element analyses and experimental measurements both confirm the feasibility of this design. When manufacturing defects are present, experimental results indicate that the actuator displacement can be optimized by adjusting the phase difference between the dual top electrodes. 相似文献
10.
Electrothermally activated paraffin microactuators 总被引:2,自引:0,他引:2
A new family of electrothermally activated microactuators that can provide both large displacements and forces, are simple to fabricate, and are easily integrated with a large variety of microelectronic and microfluidic components are presented. The actuators use the high volumetric expansion of a sealed, surface micromachined patch of paraffin heated near its melting point to deform a sealing diaphragm. Two types of actuators have been fabricated using a simple three mask fabrication process. The first device structure consists of a 9 μm thick circularly patterned paraffin layer ranging in diameter from 400 to 800 μm all covered with a 4-μm-thick metallized p-xylylene sealing diaphragm. All fabricated devices produced a 2.7-μm-peak center deflection, consistent with a simple first order theory. The second actuator structure uses a constrained volume reservoir that magnifies the diaphragm deflection producing consistently 3.2 μm center diaphragm deflection with a 3-μm-thick paraffin actuation layer. Microactuators were constructed on both glass and silicon substrates. The actuators fabricated on glass substrates used between 50-200 mW of electrical power with response times ranging between 30-50 ms. The response time for silicon devices was much faster (3-5 ms) at the expense of a larger electrical power (500-2000 mW) 相似文献
11.
Jean-Marc Jézéquel 《Software and Systems Modeling》2008,7(2):209-218
A model is a simplified representation of an aspect of the world for a specific purpose. In complex systems, many aspects
are to be handled, from architectural aspects to dynamic behavior, functionalities, user-interface, and extra-functional concerns
(such as security, reliability, timeliness, etc.). For software systems, the design process can then be characterized as the
weaving of all these aspects into a detailed design model. Model Driven Design aims at automating this weaving process, that
is automatically deriving software systems from theirs models. This paper explores the relationship between modeling and aspect
weaving. It points out some of the challenges related to such automatic model weaving, illustrating them with the example
of a weaving process for behavioral models represented as scenarios.
This work has been partially supported by the AOSD-Europe Network of Excellence.
相似文献
Jean-Marc JézéquelEmail: |
12.
直接数字频率合成器DDS的优化设计 总被引:3,自引:2,他引:3
在深入理解DDS基本原理的基础上,采用多级流水线控制技术对DDS的VHDL语言实现进行了优化,并进行了异步接口的同步化设计,给出了DDS系统的时序仿真结果及其在FPGA中的资源占有率。 相似文献
13.
14.
W.A.M. Alwis 《Computers & Structures》1985,21(4):751-757
Optimality criteria for minimum volume design are derived for a class of arch-networks comprising of pin-supported arches contained in vertical planes. The supports lie in a horizontal plane and the loads are applied vertically. It is assumed that the arches transmit loads by axial compression and the interaction among arches at intersections is by vertical reactions. It is shown that in the optimal arch-network, the centroids of all arches lie on a single surface and each individual arch is of an optimal form. An iterative numerical procedure to obtain the optimal solution for a given layout plan of arches and the loading on it is presented. Two examples are provided for the purpose of illustration. 相似文献
15.
H. Fujita 《Microsystem Technologies》1995,1(2):93-97
This paper gives a concise review of IC-compatible micromachining technologies and various types of microactuators fabricated by such technologies. A system architecture oriented to micro systems is proposed. Promising fields of application are briefly overviewed. 相似文献
16.
17.
Donald B.R. Levey C.G. McGray C.D. Rus D. Sinclair M. 《Journal of microelectromechanical systems》2003,12(6):947-959
The ability for a device to locomote freely on a surface requires the ability to deliver power in a way that does not restrain the device's motion. This paper presents a MEMS actuator that operates free of any physically restraining tethers. We show how a capacitive coupling can be used to deliver power to untethered MEMS devices, independently of the position and orientation of those devices. Then, we provide a simple mechanical release process for detaching these MEMS devices from the fabrication substrate once chemical processing is complete. To produce these untethered microactuators in a batch-compatible manner while leveraging existing MEMS infrastructure, we have devised a novel postprocessing sequence for a standard MEMS multiproject wafer process. Through the use of this sequence, we show how to add, post hoc , a layer of dielectric between two previously deposited polysilicon films. We have demonstrated the effectiveness of these techniques through the successful fabrication and operation of untethered scratch drive actuators. Locomotion of these actuators is controlled by frequency modulation, and the devices achieve maximum speeds of over 1.5 mm/s. 相似文献
18.
《Sensors and actuators. A, Physical》2007,133(2):294-300
Paraffin wax exhibits a volumetric expansion of ∼15%, at around its melting point. By exploiting this phenomenon, high performance bulk-machined electrothermal hydraulic microactuators have been demonstrated. The microactuators have been integrated into microfluidic valves, microgrippers and micropipettes. The paraffin wax is confined within a bulk-micromachined silicon container. This container is sealed using an elastic diaphragm of PDMS, while it is heated via gold microheaters located on an underlying glass substrate. All the layers used to make up the containers are bonded together using a unique combination of overglaze paste and PDMS. The hydraulic pressure of expanding paraffin wax was determined using the deflection theory of a circular plate. For the first time, the hydraulic pressure of expanding paraffin wax was calculated using the theory of large deflections for a circular plate and measured data from the type-A microgripper. This theory has been exploited for the deflection analysis of micromachined thin elastic diaphragms. In order to calculate the hydraulic pressure, the theory of large deflections of a circular plate is calculated using the measured actuation height, the PDMS diaphragm dimension of the microgripper (type-A) and mechanical properties of the PDMS. The hydraulic pressure was calculated to be approximately 0.12 MPa. All the devices were successfully demonstrated and operated at either 10 or 15 V. 相似文献
19.
Ye Qing Chuan Rhuggenaath Jason Zhang Yingqian Verwer Sicco Hilgeman Michiel Jurgen 《Annals of Mathematics and Artificial Intelligence》2021,89(7):675-691
Annals of Mathematics and Artificial Intelligence - Designing auction parameters for online industrial auctions is a complex problem due to highly heterogeneous items. Currently, online auctioneers... 相似文献
20.
Tsai Chih-Ta Muna Yirga Belay Lin Hsueh-Yuan Kuo Cheng-Chien Hsiung Rainy 《Microsystem Technologies》2021,27(4):1267-1281
Microsystem Technologies - Universally, solar power microsystem for mini-grid is acceptable as a new approach to solve the global energy problem. Improving population lifestyle as well as the... 相似文献