<p dir="ltr">In this research, a novel acoustic sensor with a waveguide is made to induce the local volumetric resonance of concrete material. The sensor is embedded in fresh concrete and monitors the in-place elastic modulus and strength development of the concrete. The resonant peak of the EMI spectrum of the sensor is governed by the concrete material in the proximate area of the sensor. The sensor itself does not affect the position of the resonant peak.</p><p dir="ltr">This research covers theoretical demonstration, sensor design and prototyping, remote testing systems, experimental study, and machine learning. Current work demonstrated the sensor successfully produced the resonant peaks that are related to the concrete curing process (R-square=0.86 for lab testing and R-square=0.64 for field testing); however, the sensitivity (S=1.00 Hz/psi) of the resonant frequency is not sufficient for practical application.</p><p dir="ltr">Machine learning algorithms were employed to map the EMI spectra to concrete strength profile. Several existing architectures were explored and evaluated. A novel machine learning scheme was proposed and successfully improved the accuracy of prediction. The algorithm is also able to handle real-time data with decent generalization among diverse concrete mixtures.</p><p dir="ltr">The integration test for the sensing system, including the sensor, the data collection device, the data pipeline, and the trained machine learning models, was performed in field testing of eight States. The averaged MAPE of the field prediction results is 23.43% for field structures and 16.13% for companion beam samples.</p><p dir="ltr">The knowledge produced during this study further advanced the application of EMI sensors in the NDE of concrete material. The EMI resonator tailored for local structural resonance is reported in this study for the first time. The EMI data processing algorithm using machine learning that is generalizable among various concrete mixtures is employed in this study for the first time. This study would be helpful for the real-world application of the EMI technique in the NDE of concrete and other phase-changing materials.</p>

<p dir="ltr">Cell polarity as defined by biologists is the cell ability to sense, determine its direction and orient itself in specific direction (e.g., front and back, top and bottom, and inside and outside). Recent studies have shown that loss of cell polarity at the tissue-level is a signature of a tumor. Detecting tumor cells based on their polarization, i.e., their electrical permittivity at the single-cell level could open the door for potential new diagnosing tools. Developing sensitive tools that are affordable and can perform fast reading is an after-sought goal. Currently, biochemical techniques are the adapted methods for research and analysis. These techniques include fluorescence-based, affinity-based, electrochemistry-based, and optical-based methods. The main disadvantages of these methods are their bulky size, and high cost due to the use of the complex pre-labeling and cannot handle small numbers of cells. On the other hand, biophysical sensing techniques for single cell focus on the whole cell intrinsic properties such as molecular compositions, volume, mass, electrical properties (i.e., conductivity and permittivity), mechanical properties. Biophysical sensing based on electrical methods would be non-invasive, fast, safe for the cells, and affordable. </p><p dir="ltr">In this thesis, novel sensors for single-cell detection are presented. Design, simulation, fabrication, and in some cases, experimental characterization of these proposed microfluidic sensors are discussed in details. The use of low and high frequency readouts for cell detection as well as the long-term goal of integration as a CMOS sensing platform are demonstrated. Detection and counting of air-bubbles on mm-sized RF ring resonator are demonstrated as a first proof of concept. Miniaturized RF ring resonator and co-planar-waveguide (CPW) devices that are integrated with microfluidic channels to characterize single-cells are then discussed. Furthermore, a novel CMOS capacitor sensor for cell detection is proposed for the first time. The idea of the proposed sensor is based on a perforated MIM capacitor that allows the detection of cells by a change in the dielectric constant of the capacitor perforated with a micro-channel.</p>

<p>With the advent of increasingly complex radio systems at higher frequencies and the slowing of traditional CMOS process scaling with power concerns, there has been an increased focus on integration, architectural, and material innovations as a continued path forward in MEMS and logic. This work presents the first comprehensive experimental study of resonant body transistors in a commercial 14nm FinFET process, demonstrating differential radio frequency transduction as a function of transistor biasing through electrostatic, piezoresistive, and threshold voltage modulation. The impact of device design changes on unreleased resonator performance are further explored, highlighting the importance of phononic confinement in achieving an f*Q product of 8.2*10¹¹ at 11.73 GHz. Also shown are initial efforts towards the understanding of coupled oscillator architectures and a perovskite nickelate material system. Finally, development of resonators based on two-dimensional materials, whose scale is particularly attractive for high-frequency nano-mechanical resonators and acoustic devices, is discussed. Experiments towards dry transfer of tellurene flakes using geometries printed via two photon polymerization are presented along with optimization of a fabrication process for gated RF devices, presenting new opportunities for high-frequency electro-mechanical interactions in this topological material. </p>

Metamaterials are humanly engineered artificial electromagnetic materials which produce electromagnetic properties that are unusual, yet can be observed readily in nature. These unconventional properties are not a result of the material composition but rather of the structure formed. The objective of this thesis is to investigate and design smaller and wideband metamaterial-inspired antennas for personal communication applications, especially for WiMAX, lower band and higher band WLAN applications. These antennas have been simulated using HFSS Structure Simulator and CST Microwave Studio software. The first design to be analysed is a low-profile metamaterial-inspired CPW-Fed monopole antenna for WLAN applications. The antenna is based on a simple strip loaded with a rectangular patch incorporating a zigzag E-shape metamaterial-inspired unit cell to enable miniaturization effect. Secondly, a physically compact, CSRR loaded monopole antenna with DGS has been proposed for WiMAX/WLAN operations. The introduction of CSRR induces frequency at lower WLAN 2.45 GHz band while the DGS has provided bandwidth enhancement in WiMAX and upper WLAN frequency bands, keeping the radiation pattern stable. The next class of antenna is a compact cloud-shaped monopole antenna consisting of a staircase-shaped DGS has been proposed for UWB operation ranges from 3.1 GHz to 10.6 GHz. The novel shaped antenna along with carefully designed DGS has resulted in a positive gain throughout the operational bandwidth. Finally, a quad-band, CPW-Fed metamaterial-inspired antenna with CRLH-TL and EBG is designed for multi-band: Satellite, LTE, WiMAX and WLAN.

The objectives of this work are to review, investigate and model the microwave planar filters of the modern wireless communication system. The recent main stream of microwave filters are classified and discussed separately. Various microwave filters with detailed applications are investigated in terms of their geometrical structures and operational performances. A comprehensive theoretical study of microwave filters is presented. The main types of microwave filters including the basic low-pass filters such as Butterworth and Chebyshev filters are fully analysed and described in detail. The transformation from low-pass prototype filters to high-pass filters, band-pass filters and band-stop filters are illustrated and introduced. Research work on stepped impedance resonator (SIR) and asymmetric stepped impedance resonator (ASIR) structure is presented. The characteristics of λg/4, λg/2 and λg (λg is the guided wavelength of the fundamental frequency in the free space) type SIR resonators, and the characteristic of asymmetric SIR resonator are categorized and investigated. Based on the content mentioned above, novel multi-standard high performance asymmetric stepped impedance resonator single-wideband and dual-wideband filters with wide stopbands are proposed. The methodologies to realize wide passband and wide stop-band filters are detailed. In addition, multi-standard high performance triplewideband, quadruple-wideband and quint-wideband filters are suggested and studied. The measurement results for all prototype filters agree well with the theoretical predictions and simulated results from Ansoft HFSS software. The featured broad bandwidths over single/multiple applicable frequency bands and the high performances of the proposed filters make them very promising for applications in future multistandard wireless communication.

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<p>Developing a hybrid platform that combines nanophotonic circuits and atomic physic may provide new chip-scale devices for quantum application or versatile tools for exploring photon-mediated long-range quantum systems. However, this challenging project demands the excellent integration of cold atom trapping and manipulation technology with cutting-edge nanophotonics circuit design and fabrication. In this thesis project, we aim to develop a novel suspended membrane platform that serves as a quantum interface between laser-cooled, trapped atoms in an ultrahigh vacuum and the photons guided in the nanophotonic circuits based on high-quality silicon nitride microring resonators fabricated on a transparent membrane substrate. </p> <p><br></p> <p>The proposed platform meets the stringent performance requirements imposed by nanofabrication and optical physics in an ultra-high vacuum. These include a high yield rate for mm-scale suspended dielectric photonic devices, minimization of the surface roughness to achieve ultrahigh-optical quality, complete control of optical loss/in-coupling rate to achieve critical photon coupling to a microring resonator, and high-efficiency waveguide optical input/output coupler in an ultrahigh vacuum environment. This platform is compatible with laser-cooled and trapped cold atoms. The experimental demonstration of trapping and imaging single atoms on a photonic resonator circuit using optical tweezers has been demonstrated. Our circuit design can potentially reach a record-high cooperativity parameter C$>$500 for single atom-photon coupling, which is of high importance in realizing a coherent quantum nonlinear optical platform and holds great promise as an on-chip atom-cavity QED platform.</p>

In this paper, we present the design guidelines for a tunable optical isolator in an SOI-based ring resonator with two small time-modulated regions. By considering a physical model, the proper geometrical and modulation parameters are designed, based on a standard CMOS foundry process. The effect of the variation of the key parameters on the performance of the isolator is explained by two counter-acting mechanisms, namely the separation between the resonance frequencies of counter-rotating modes and energy transfer to the side harmonic. We show that there is a trade-off between these parameters to obtain maximum isolation. Consequently, by applying the quadrature phase difference one can obtain the maximum separation between the resonance frequencies and hence the minimum insertion loss, while the maximum isolation is obtained at the modulation phase difference of −0.78π , which leads to a higher insertion loss. Robustness of the design is investigated through a sensitivity analysis for the fabrication variations in the distance and width of the modulated regions. We demonstrate that there is a trade-off between isolation and insertion loss, and by varying the modulation parameters, we can achieve isolation of 18 (5) dB with 7 (1.8) dB insertion loss.