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This paper reports on the preparation and the swelling studies of glucose hydrogel for microvalve. This glucose hydrogel were synthesized with 80 mg Acrylamide (Aam) and crosslinked with a bifunctional crosslinking agent, 0.5 mg N,Npsila Methylene-Bisacrylamide (Bis). The hydrogel polymerization were initiated with 0.5 mg Ammonium Persulfate (APS) and the reaction rate is accelerated by the addition...
Pure and ZnO-Ti mixed nanowires were synthesized on a p-type silicon wafer. ZnO powder and Ti were mixed and mechanically milled in a ball milling machine. ZnO-Ti mixed nanowires were grown from the milled powder by using thermal evaporation method. Pure and ZnO-Ti mixed nanowires were grown by vapor solid method, using a furnace at 1000degC on a p-type silicon wafer. Characterizations have been done...
Carbon Nano Tubes (CNTs) are potential candidate to be used in nano transistors and interconnection inside the ICs. In most of these applications, speed of the carriers is very important. Due to small sizes of CNTs, the mobility of electrons is ballistic. On the other hand because of the superabundant free electrons, most of CNTs are in the degenerate regime, where Boltzmann statistics can not be...
This paper presents parametric simulations of a micromachined mesoscopic acoustic speaker for hearing aid applications. The microspeaker has a single turn copper coil on a polyimide membrane, and a NdFeB permanent magnet beneath the membrane. The fields due to the permanent magnet were computed using FEMM. Then, forces based on the fields and on the coil driving current were computed. Finally, IntelliSuite...
A very low pressure sensor has been proposed to be used in the eye for glaucoma treatment with pressure ranging from 10 mmHg to 75 mmHg. This paper presents process development of thin layer membrane for very low pressure sensor application. The structure of the membrane consists of parallel plate which both top and bottom electrodes were fixed at both sides. Utilizing CMOS compatible process, fabrication...
Zinc oxide (ZnO) nanowires have been synthesized using thermal evaporation approach on quartz (SiO2) substrates in nitrogen atmosphere with a mixture of milled ZnO and graphite powder as reactants. Ohmic behavior has been obtained for both Ag and Au/Ag contact to ZnO nanowires. The samples were re-examined after annealing at 300degC, 400degC and 500degC. The optimum annealing temperature for obtaining...
The flow behaviour in a valveless micropump is analyzed using the Fluid Structure Interaction (FSI) method. To accurately predict the working behavior of the micropump based on the fluid equations, structural equations and piezoelectric equations, the fluid-structure dynamic coupling effects should be taken into account. Accurate analysis of fluid-structure interaction of the micropump involves in...
A hydrogel actuated microsystem employed in controlling the opening-closing states of a microvalve is described. This microsystem consists of a flexible silicone rubber diaphragm with an attached silicon boss and a cantilever beam. Swelling of the hydrogel forces the bossed membrane and consequently the cantilever beam to be deflected. Simulations were done by FEM analysis and the results show enough...
In this work, an analytical method is introduced to optimize the structure of a MEMS LC pressure sensor based on the device pressure range, the maximum overload pressure, and other design constraints. The method can be applied to square and circular membrane sensors. The sensitivity of the LC structure is directly proportional to the sensitivity of its capacitor. To obtain the maximum sensitivity...
Research on microneedles has been increasing rapidly to overcome the drawbacks of hypodermic needle which can results in painful injection, tissue damage and uncontrollable delivery rate. This paper presents process characterization of wet isotropic etching for solid microneedles array development. Work has been carried out to investigate the isotropic etching behavior in 17 different compositions...
This paper will describe how a novel single-chip capacitive microphone was successfully fabricated on silicon wafer using MEMS process. The capacitive microphones generally consist of a diaphragm, back plate and air gap. The novelties of the method relies on the moveable aluminum (Al) diaphragm positioned over the backplate electrode, where the diaphragm includes a plurality of holes to allow the...
In this paper, we attempt to design, simulate and characterize an InGaAs-based vertical-cavity surface-emitting laser (VCSEL) employing InGaAsP multi-quantum wells sandwiched between GaAs/AlGaAs and GaAs/AlAs distributed Bragg reflectors using an industrial-based numerical simulator. We were able to obtain a working model at an optical wavelength of 1.55 mum. This paper provides key results of the...
A surface micromachining technique is proposed which significantly reduces the undesirable pattern following effect and prevents disturbance in subsequent layers of the structure. This modified lift off method starting from a flat surface embeds the base layer of microstructure in the substrate in order to maintain initial surface profile, and thus allows fabrication of subsequent layers to start...
This paper reports the synthesis of highly lumimescence CdSe quantum dots via wet-chemical process and the study of the surfactant concentration effect on the improvement of the photoluminescence characteristic. Here, we also discussed in detail the quantum dots synthesis procedure and the mechanism for the improvement of the luminescence characteristic of CdSe quantum dots under a different surfactant...
A realistic approach for modelling a fixed-fixed beam is presented. The use of probabilistic methods to assess the electromechanical behaviour of the beam under the presence of micro-machine manufacturing and process uncertainties is demonstrated. A finite-element model of the beam is constructed using the commercial code ANSYS (10.0). In the standard approach of modelling, existing literature assumes...
This paper presents a low cost and low insertion loss Ku-band bandpass filter (BPF) based on inexpensive commercial FR4 (epsivr.= 4.3) substrate. The filter is designed on 0.6 mm-thik substrate using microstrip technology by following the design procedure based on even- and odd-mode impedances of the coupled lines. Microstrip technology is used for simplicity and ease of fabrication. The design and...
There is an increasing demand for newer microwave and millimeter-wave systems to meet the emerging telecommunication challenges with respect to size, performance and cost. Micro electro mechanical systems (MEMS) have several desirable features, including small size, high performance, low power consumption and low loss. This paper presents an X- band probe fed small rectangular microstrip patch antenna...
The common defects that could occur during the fabrication and long term operation of a tunable bandpass filter using RF MEMS switches are simulated with SONNET. The faulty responses of the defective filter are then analyzed and linked to the defects that cause them. The work carried out aims at being able to narrow down and possibly identify the defects quickly in future by measuring the faulty filter...
The purpose of this paper is to discuss the effect of Nickel (Ni) thickness on lead free solder joint material for tape ball grid array (TBGA) application. In this study, four different level of Nickel thickness were chose that is 3 um, 4 um, 5 um and 6 um. Ball pull testing was used to assess the solder joint performance at time zero, after multiple reflow and high temperature storage (HTS). The...
Operating a library involves in keeping track large number of resources such as books and magazines. Radio Frequency Identification (RFID) technology has been promoted in recent years as an alternative technology in improving asset management in a library. The RFID tags were applied to replace bar code and magnetic stripe functions as identification and anti-theft detection. This paper is written...
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