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The purpose of this paper is to design an out-of-plane micro electro-thermal-compliant actuator based logic gates which work analogously to complementary metal oxide semiconductor (CMOS) based logic gates. The proposed logic gates used a single-bit mechanical micro ETC actuator per logic instead of using 6-14 individual transistors as in CMOS.

A complete analytical modelling is performed on a single ETC vertical actuator, and a relation between the applied voltage and the out-of-plane deflection is derived. Its coupled electro-thermo-mechanical analysis is carried out using micro electro mechanical system (MEMS) CAD tool CoventorWare to illustrate its performance.

This paper reports analytical and numerical simulation of basic MEMS ETC actuator-based logic gates. The proposed logic gate operates on 5 V, which suits well with conventional CMOS logic, which in turn reduces the power consumption of the device.

The proposed logic gates uses a single-bit MEMS ETC actuator per logic instead of using more transistors as in CMOS. The unique feature of this proposed logic gates is that the basic mechanical ETC actuator is customized in its structure to function as specific logic gates depending upon the given inputs.

This paper aims to show an evolutionary topology optimization procedure for the design of compliant electro-thermal mechanisms.

The adopted methodology is based in the evolutionary structural optimization (ESO) method. This approach has been successfully applied by this group for compliant mechanisms optimization under directly applied input loads and simple thermal loads. This work proposes an extension of this procedure, based on an additive version of the method, to solve the more complicated case of electro-thermal actuators optimum design, based on Joule's resistive heating.

Examples solved for the design of plane compliant mechanisms are presented to check the validity of this technique. The designs obtained are compared favorably with results obtained by other authors to illustrate and validate the method, showing the viability of this technique for the optimization of compliant mechanisms under electro-thermal actuation.

This investigation is based on and additive version of the evolutionary method. Since this approach does not have the capability to remove material it could be combined with the classic element rejection evolutionary method to overcome these deficiencies, developing an improved bi-directional algorithm, which should be analyzed and applied for these types of designs in future works.

Electro-thermal actuators have widespread use in MicroElectroMechanical Systems applications. Since these elements cannot be manufactured using typical assembly processes compliant mechanisms optimization play a crucial role for their successful design. The proposed methodology could help engineers to rapidly conceive complex and efficient actuators.

The topology optimization procedure developed in this paper enables systematic design of these devices, which can result in a save of manufacturing time and cost.

Most applications of the ESO method have considered maximum stiffness structure design, and even if it has been successfully applied to some other optimum material distribution problems, electro-thermal actuators design has not been considered yet. This paper shows that this methodology could be useful also in the design of electro-thermal compliant mechanisms, and provides engineers with a very simple and practical alternative design tool.

To develop new and existing coupled thermal and mechanical models of electromagnetic solids for the simulation of coupled field problems based on a consistent theoretical and computational framework.

The finite element computational models we describe involve the combination of classical electrodynamics, continuum mechanics, and thermodynamics. In order to create consistent coupled models, we employ the fundamental principles of thermodynamics as a common framework.

Our procedure requires the necessary thermodynamical considerations for building consistent multiphysics models and develops some novel implementation issues that are important from the designers' point of view. Additionally, efficient numerical algorithms for solving the arising static and dynamic nonlinearities are discussed.

The paper targets the simulation of coupled problems in macroscopic electromagnetic continua.

The application areas of the coupled field models are identified and illustrated by the solution of complex industrial problems.

We introduce new computational models and techniques for the solution of some coupled field problems in electromagnetic solids. While some elements of these computational models and techniques have been used for decades, the complete theoretical and computational framework is presented for the first time here.

The purpose of this paper is to describe an element addition strategy for topology optimization of thermally actuated compliant mechanisms under uniform temperature fields.

The proposed procedure is based on the evolutionary structural optimization (ESO) method. In previous works, this group of authors has successfully applied the ESO method for compliant mechanism optimization under directly applied input loads. The present paper progresses on this work line developing an extension of this procedure, based on an additive version of the method, to approach the more complicated case of thermal actuators.

The adopted method has been tested in several numerical applications and benchmark examples to illustrate and validate the approach, and designs obtained with this method are compared favorably with the analytical solutions and results derived by other authors using different optimization methods, showing the viability of this technique for uniformly heated actuators optimization.

As a simple initial approach, this research considers only uniform heating of the system, while many thermal actuators are heated nonuniformly. Future works will be based on electrothermal actuation, and nonuniform Joule heating will be considered as well, which might lead to more elegant and efficient solutions.

Compliant micromechanisms that are responsible for movement play a crucial role in microelectromechanical systems (MEMS) design, which cannot be manufactured using typical assembly processes and may not make use of traditional hinges or bearings. The topology optimization method described in this paper enables the systematic design of these devices, which can result in reduced conception time and manufacturing cost.

The ESO method has been successfully applied to several optimum material distribution problems, but not for thermal compliant mechanisms. Even if most applications of this method have been oriented for maximum stiffness structure design, this paper shows that this computation method may be also useful in the design of thermal compliant mechanisms and provides engineers with a very simple and practical alternative design tool.

This paper aims to focus on the numerical modelling of 3D structure of surface micromachined (MEMS) accelerometers.

The paper focuses on the methods of mechanical design and analysis of electrostatic accelerometers (comb drive structure) and uses computer simulation procedure leading to final structure design, then to be defined as a basic structure for stress analysis.

The strategy in computer modeling of accelerometer MEMS is satisfactory in order to simulate the electromechanical characteristics of different accelerometer structures (IMEMS).

A novel complex strategy in computer modeling of accelerometer MEMS, based on solid modeling is proposed.

This paper aims to describe a method for efficient frequency domain model order reduction. The method attempts to combine the desirable attributes of Krylov reduction and proper orthogonal decomposition (POD) and is entitled Krylov enhanced POD (KPOD).

The KPOD method couples Krylov’s moment-matching property with POD’s data generalization ability to construct reduced models capable of maintaining accuracy over wide frequency ranges. The method is based on generating a sequence of state- and frequency-dependent Krylov subspaces and then applying POD to extract a single basis that generalizes the sequence of Krylov bases.

The frequency response of a pre-stressed microelectromechanical system resonator is used as an example to demonstrate KPOD’s ability in frequency domain model reduction, with KPOD exhibiting a 44 per cent efficiency improvement over POD.

The results indicate that KPOD greatly outperforms POD in accuracy and efficiency, making the proposed method a potential asset in the design of frequency-selective applications.

This paper aims to propose a method to reduce the resistance of silicon-based V-shaped electrothermal microactuator (VEM) by applying a surface sputtering process.

Four VEM’s samples have been fabricated using traditional silicon on insulator (SOI)-Micro-electro-mechanical System (MEMS) technology, three of them are coated with a thin layer of platinum on the top surface by sputtering technique with different sputtered times and the other is original. The displacements of the VEM are calculated and simulated to evaluate the advantages of sputtering method.

The measured results show that the average resistance of the sputtered structures is approximately 1.16, 1.55 and 2.4 times lower than the non-sputtering sample corresponding to the sputtering time of 1.5, 3 and 6 min. Simulation results confirmed that the maximum displacement of the sputtered VEM is almost 1.45 times larger than non-sputtering one in the range of voltage from 8 to 20 V. The experimental displacements are also measured to validate the better performance of the sputtered samples.

The experimental results demonstrated the better displacement of the VEM structure after using the platinum sputtering process. The improvement can be considered and applied for enhancing displacement as well as decreasing the driving voltage of the other electrothermal microactuators like U- or Z-shaped structures while combining with the low-cost SOI-MEMS micromachining technology.

To present a general synthesis method in the design of variable comb drive MEMS capacitors which can provide specified capacitance versus position profiles while give large tuning range.

By carefully choosing design parameters and constraint conditions, the design process is implemented as the solution of a constraint optimization problem. An electric field analysis software based on the finite element method and an optimization software based on the evolutionary stochastic search are chosen to work together to implement the system.

The results verify that the shape of a variable MEMS capacitor has a great influence on the capacitance versus distance profile and demonstrates that a specific geometry of the MEMS capacitor can be found to match a desired capacitance‐distance profile.

The analytical expression for the capacitance formed between the fixed and the movable fingers is somewhat inaccurate. The results are not compared to measurement because no device has been fabricated.

A very successful numerical simulation example and guidance for MEMS designers to develop MEMS devices with variable electrode shapes.

This paper proposes a systematic way for the design of MEMS tunable capacitors with variable shape. The approach can be used to design MEMS devices with variable electrode shapes to satisfy specific requirements.

The purpose of this paper is to explore a new possibility of providing high-temperature stable lead-free interconnections for low-temperature co-fired ceramics (LTCC) hotplate. For gas-sensing application, a temperature range of 200°C-400°C is usually required by the sensing film to detect different gases which imply the requirement of thermally stable interconnects. To observe the effect of parameters influencing power of the device, electro-thermal simulation of LTCC hotplate is also presented. Simulated LTCC hotplate is fabricated using the LTCC technology.

The proposed task is to fabricate LTCC hotplate with interconnects through vertical access. Dedicated via-holes generated on the LTCC hotplate are used to provide the interconnections. These interconnections are based on adherence and bonding mechanism between LTCC and thick film. COMSOL software is used for finite element method (FEM) simulation of the LTCC hotplate structure.

Thermal reliability of these interconnections is tested by continuous operation of hotplate at 350°C for 175 h and cycling durability test performed at 500°C. Additionally, vibration test is also carried out for the hotplate with no damage observed in the interconnections. An optimized firing profile to reproduce these interconnections along with the experimental flowchart is presented.

Research activity includes design and fabrication of LTCC hotplate with metal to thick-film based interconnections through vertical access. Research work on interconnections based on adherence of LTCC and thick film is limited.

A new way of providing lead-free and reliable interconnections will be useful for gas sensor fabricated on LTCC substrate. The FEM results are useful for optimizing the design for developing low-power LTCC hotplate.

Adherence and bonding mechanism between LTCC and thick film can be used to provide interconnections for LTCC devices. Methodology for providing such interconnections is discussed.