Planar £gPEM Fuel Cell Stacks are designed and fabricated in-house through a deep UV lithography technique, with SU 8 photoresist used as the microstructure mold for the fuel cell flow channel or bipolar plates when micro electroforming. The fuel cell stacks use a new design which means installing the fuel channel into PMMA, by which the fuel supply channel becomes convenient and simplified. The performance of the stack is measured in different inlets, and the effect of the hydrogen inlets is explained. The experimental results are presented in the form of polarization VI curves and PI curves for the different types of inlet. Furthermore, the influence of the inlets is presented and discussed.

As the microwave wireless communication systems growing rapidly, microstrip planar ceramic filters attract many attentions because of the advantages of small size, low cost, easy fabrication, higher performance and easy integration. In this thesis, several kinds of bandpass filters are designed for different operating purposes. First, two kinds of dual-mode bandpass filters are designed for 2.4 GHz wideband with the T-shaped I/O arranging in a straight way for easy integration. Second, the hook-coupling and insert-coupling structures are adopted for series connecting of the stepped-impedance resonator structures, and 2.4/5.2 GHz dual-band filtering properties could be achieved. Third, two open-loop rectangular ring resonators and U-shaped I/O are designed for 2.4/5.2 GHz dual-band bandpass filters with deep transmission zeros. The quarter wavelength stubs and groove structures are used for enhancing deep transmission zeros between two passband and ripples of the second passband, respectively. Fourth, the parallel positioned resonators with phase difference method are used to design the dual-band (1.23/2.4 GHz) and quad-band (1.23/2.4/3.5/5.2 GHz) bandpass filter with asymmetrical bandwidths and transmission zeros. In the thesis, high quality Al2O3 ceramic substrates are used to fabricate different kinds of bandpass filters for pattern minimization and low losses. The electromagnetic simulators, HFSS and IE3D, were used to adjust and optimize the associated parameters. The printing method was used to fabricate the proposed bandpass filters, which did not need using the FeCl3 to etch the Cu plate from the surface of Duroid or the FR4 substrates. The proposed filters are measured by Agilent-N5230A with the SMA connectors welding. Finally, the simulated and measured results of proposed bandpass filters are in good agreement.

Reducers are commonly used in many types of machines to reduce the speed and increase the torque of motors. For general industrial applications, the reduction ratio of a reducer is usually limited in consideration to its size. To provide high reduction ratios, harmonic drives (speed reducers) can be made very compact and lightweight and thus have been popular with robot manufactures and in other applications where weight is critical. In this study, an innovative design for reducers composed of planar cams and roller followers with high reduction ratios is proposed. It uses the relative motion between rollers and their cams to generate a high reduction ratio. In this thesis, the synthesis procedure of the reducer and the analysis results of the kinematic and dynamic characteristics based on the design parameters are also described. Furthermore, the experiments for testing and verifying the characteristics of the reducer are presented. Finally, a set of design parameters which meets the demand of an application is found by optimization methods.

As inspired by the coordination environment of nickel in NikR and NiSOD, imidazole ligands were incorporated into N2SNiII square planar complexes in order to investigate the electronic and structural features of NiII species containing both imidazole and thiolate ligation. Rare examples of nickel complexes containing such ligand sets in continuous tetradentate (N2N'S) and discontinuous (N2S---N') coordination were synthesized and characterized. A significant finding in these studies is that the plane of the imidazole ligand is oriented perpendicular to the N2SNi plane. Further investigations addressed the orientational preference and stereodynamic nature of flat monodentate ligands (L = imidazoles, pyridine and an N-heterocyclic carbene) bound to planar N2SNi moieties. The solid state molecular structures of planar [N2SNiL]n+ complexes accessed through bridge-splitting reactions of dimeric, thiolate-S bridged [N2SNi]2 complexes, reveal that the plane of the added monodentate ligand orients largely orthogonal to the N2SNiL square plane. Variable temperature 1H NMR characterization of dynamic processes and ground state isomeric ratios of imidazole complexes in their stopped exchange limiting spectra, readily correlate with DFT-guided interpretation of Ni-L rotational activation barriers. Full DFT characterization relates the orientation mainly to steric hindrance derived both from ligand and binding pocket. In the case of the imidazole ligands a minor electronic contribution derives from intramolecular electrostatic interactions (imidazole C-2 C-H[superscript delta]+- - S[superscript delta]- interaction). Our group has firmly established the versatility of the (bme-daco)2-, (bme-dach)2-, and (ema)[left arrow]- ligands to accommodate a number of metals (M = Ni, Zn, Cu, and Fe ), and have demonstrated reactivity of such N2S2M complexes occurs predominately at the S-thiolate sites. As vanadium is of interest for its biological, pharmacological and spectroscopic/analytical probe abilities, vanadyl analogues were explored as mimics of possible chelates formed from Cys-X-Cys binding sites in vivo. The structural and electronic changes from the incorporation of V=O2+ in such dianionic and tetraanionic N2S2 binding pockets is investigated and compared to Ni2+ and Zn2+ in similar N2S2 environments. The nucleophilicity of the S-thiolate in these systems is explored with alkylating agents and W(CO)x. Furthermore, the vanadyl interaction with the CGC peptide, the biological analogue of the tetraanionic N2S2 ligand, was produced and characterized by EPR; its W(CO)x adducts were indentified by ?(CO) infrared spectroscopy.

A multi-axis compact positioner is designed and implemented in this thesis. The single-moving-part positioner is designed to move in the magnetic field generated by a superimposed concentrated-field permanent magnet matrix. The compact positioner is primarily for the stepping and scanning applications that require 3-DOF planar motions. In which, the travel ranges in two orthogonal directions are on the order of 100 mm. The moving platen, which has the size of 185.4 mm x 157.9 mm and weighs 0.64 kg, mainly comprises of a plastic frame and six copper coils. It is actuated in the horizontal plane by flowing six independent electric currents into the coils. The platen is supported against gravity by three air bearings. Force calculation is based on the Lorentz force law. With a current-carrying rectangular coil placed in the magnetic field of the supper-imposed Hallbach magnet matrix, the force acting on the coil is calculated by volume integration. The distances between the longer sides and between the shorter sides of the rectangular coil are designed to fit a half pitch and one pitch of the Hallbach magnet array, respectively. Therefore, the volume integration is simplified considerably. The force-current relation for the entire platen with six coils is derived. Three Hall-effect sensors are attached to the moving platen to measure the magnetic flux densities at the center points of the sensors. The position of the moving platen is determined by the field solution of the magnet matrix and the magnetic flux densities sensed by the Hall-effect sensors. A new discrete PID-like controller is proposed and tested. For the step responses with the step sizes within 1000 micrometers, the overshoots and the steady state errors are negligible. The achieved velocity in x is 10.50 cm/s and in y is 16.25 cm/s, respectively. The achieved acceleration in x is 43.75 cm/s^2 and in y is 95.59 cm/s^2, respectively. The achieved travel ranges are 15.24 cm in x, 20.32 cm in y, and 0.21 rad in the rotational motions about the vertical axis. The positioning resolution in x and y is 8 micrometers with the rms positioning error of 6 micrometers. The positioning resolution in rotation about the vertical axis is 130 microrad.

In the field of MEMS technology, all kinds of actuators are often regarded as the force source. However, some designs of actuators have good precision in position; the working distance to be driven is too short. Therefore, the actuator is often combined with a mechanism with displacement amplify function. The objective of this study is to synthesize the new pantograph mechanism using the concept of mechanism design according to the desirable motion and the requirement of the actuator. The cases of single degree-of-freedom and two degree-of-freedom are assumed simultaneously for the output of the basic design constraints so as to generate new pantograph mechanisms from the catalogue of kinematic chains. The suitable pantographs are then found out with the features such as: (1) single level plane using comb driver, (2) using compliant mechanisms as joints, and (3) suitable for MUMPs process. These constraints of design are considered as the procedures of process design, compliant mechanisms transformation, compliant joints design, actuator configurations design, FEM dynamic analysis and joint modifications. Finally, prototypes are evaluated and transform into planar micro compliant pantographs. Moreover, a test and a discussion of the displacement error are done under the consideration of the designed mechanism actuating using FEM analysis. The percentage of displacement error of planar micro compliant pantograph is defined, and the equation for estimating the percentage of displacement error is proposed so as to modify the motion error for controlling.

An internal small antenna usually suffers from degradation in performance of impedance bandwidth and radiation patterns. In this thesis, we design and fabricate a broadband interior type planar monopole with an omni-directional radiation pattern over a wide operation band using a slant feeding strip. It has a measured impedance bandwidth about 465MHz with center frequency at 1.66GHz (1427 ¡V 1892MHz) and the maximum cross polarization level about -13dB at 1800MHz, which is GSM1800 band in mobile communications. A modified design is an interior planar monopole with a slant slit. It has a measured impedance bandwidth about 455MHz with center frequency at 1.71GHz (1487 ¡V 1942MHz), including GSM1800 and PCS1900 band, and the maximum cross polarization level about -15dB at 1800MHz. The antennas have the dimensions of 40mm*15mm which occupies a small size on the system board and they are suitable to be mounted within the mobile handset device.

The notion of &rdquo / Planar functions&rdquo / goes back to Dembowski and Ostrom, who introduced it in 1968 first time to describe projective planes with special properties in finite geometry. Recently, they attracted an interest from cryptography because of having an optimal resistance to differential cryptanalysis.This thesis is based on the paper &rdquo / New semifields, PN and APN functions&rdquo / by J&uuml / rgen Bierbrauer. The whole purpose of this thesis is to understand and present a detailed description of the results of the paper of Bierbrauer about planar functions. Here and throughout this thesis &rdquo / new&rdquo / means &rdquo / new&rdquo / in the paper of Bierbrauer. In particular we have no new constructions here and we only explain the results of Bierbrauer.

In this thesis, two novel antennas and three advanced design concepts for further studies are presented. Firstly, the design of diversity dual-band inverted-F monopole antenna using two back-to-back stacked metallic strips for operating in the 2.4 and 5.2 GHz WLAN band is presented. Secondly, the diversity dual-band inverted-F monopole antenna mounted vertically at the edge of a system circuit board is studied. Finally, three advanced design concepts are discussed to demonstrate the methods of controlling radiation patterns to achieve better radiation characteristics of the antenna.

Most of the microgrippers developed in recent years still lack of the systematic mechanism design background in the overall design scope of microgripper. The main objective of this investigation is to find new possibilities of design concept in order to enhance the design scope of microgripper. This thesis presents the design and analysis of microgripper for microassembly that are based on the mechanism design perspective, which particularly involves the 3-D working space and planar compliant microgripper. Several feasible solutions of the microgripper with 3-D working space are presented include the use of molten solder self-assembly, hinge mechanism, shape memory alloy, electrostatic-force assembly, and magnetic-force assembly. An atlas of 28 types of planar compliant linkages for two-finger microgripper is presented based on the systematic design procedure. The FEM simulation shows the preliminary satisfactory results that reveal the good agreement with the expected kinematic motion. It can be concluded that the mechanism design concept presented in this study can be integrated into the design work of micro scale actuating device.