The 1/4£f dual-mode resonators made from c-axis-oriented aluminum nitride films grown on different conduction material have been studied in this thesis. The RF/DC sputter system is used to grow on layers of reflector. During the porcess, 3.5 pairs of Bragg reflector alternating with W and SiO2 are composed by Si substractor. To achieve 0.999 reflective rate, fabrication parameters are adjusted to make W films become £\-phase structurre. On the other hand, piezoelectric layers as well as reflective layers that using reactive RF magnetron sputtering system and means of off-axis are combined to deposite optimal resonators of shear mode quality factor (Q) resonatros. While changing the substract and target distance between various bottom electrode materials, including Si, W/Si, and Mo/Si could deposit AlN with various c-axis tilting angle which resulted in stimulating longitudinal and shear acoustic waves. Futhermore, the finding is used to discuss the growth mechanism of inclined AlN by TEM. The analysis of various distances of AlN films shows that column inclining angle and XRD-Rocking Curve £s will increase with distance. The quality of shear mode would be better when column and £s are highly shifed. About the influence on AlN deposites, AlN/Si was grown away from the center by 6 cm. AlN/Si column inclining angle is about 20 degree, and RMS could reach 2.63nm beneath. Uner AlN/W/Si, column incling angle is about 30 degree, and £s shift angle 4.14 degree, the shear mode quality factor of freaquency response is obtained to 262. Under AlN/Mo/W/Si, column incling angle would be 25.4 degree, and XRD are better-choosed c-aixsm, £s tilting angle shifs 6.72 degree, and the shear mode quality factor is obtained to 290. Film intersurface appears bigger misfit by TEM to obtain better shear mode.

Shear-mode thin film bulk acoustic resonator (TFBAR) devices with c-axis tilted AlN films are fabricated for the application of liquid sensors. To fabricate shear-mode TFBAR devices, the off-axis RF magnetron sputtering method for the growth of piezoelectric AlN thin films is adopted and influences of the relative distance and the sputtering parameters are investigated. The shrar-mode phenomenon of a TFBAR results from the tilted crystalline orientation of AlN thin films. In this thesis, the AlN thin films are deposited with tilting angles of 15¢X and 23¢X, set by controlling the deposition parameters. The properties of the AlN thin films are investigated by X-ray diffraction and scanning electron microscopy. The frequency response is measured using an HP8720 network analyzer and a CASCADE probe station. The frequency response of the TFBAR device with 23¢X tilted AlN thin film is measured to reveal its ability to provide shear-mode resonance. The resonance frequencies of the longitudinal and shear modes are 2.07 GHz and 1.17 GHz, respectively. To investigate the sensing characteristics of TFBAR, two basic experiments of mass and liquid loading are carried out. The sensitivities of the longitudinal and shear modes to mass loading are calculated to be 2295 Hz cm2/ng and 1363 Hz cm2/ng with the mechanical quality factors of 588 and 337, respectively. However, the mechanical quality factors of the longitudinal mode of TFBAR without and with a liquid loading decreased from 588 to 0, whereas those remain almost the same for the shear mode under liquid loading. The sensitivities of the longitudinal and shear modes are calculated to be 0 and 17.88 Hz cm2/£gg for liquid loading.

The purpose of this thesis is to study the c-axis inclined ZnO films to produce dual-mode thin-film piezoelectric transducer. The cantilever beam vibration theory as a power generation mode in adopted to verify that the transducer is in suitable for the application in the environment for low-frequency vibration. In order to develop dual-mode thin-film piezoelectric transducer, this study uses radio-frequency magnetron sputtering method with off-axis growth to deposit ZnO films on Pt/Ti/stainless steel substrate(SUS304), the effects of deposition parameters on the characteristict of ZnO films are studied. Because zinc oxide thin-film is grown with c-axis tilt, so the piezoelectric transducer exhibits longitudinal-mode and shear-mode characteristics. The physical characteristics of ZnO thin films were obtained by the analyses of the scanning electron microscopy (SEM) and X-ray diffraction (XRD) to discuss the surfaces, cross section and crystallization of ZnO thin films. Finally, the vibration test equipment in used for the measurement of electrical properties. The open and loaded voltages of the transducers were obtained by the measurement system. The optimal deposition parameters for ZnO thin films are sputtering pressure of 5 mTorr, RF power of 150W, substrate temperature of room temperature and oxygen concentration of 50%, which were determined by physical characteristics and voltage analysis. Under the optimal parameters, the ZnO thin-films are deposited with maximum shear-mode and tilting angles of 35¢X.The transducer was one-sid loaded with a piece of metal of 0.5 g load to enhance the cantilever vibration amplitude. As the input vibration of 65 Hz and vibration amplitude of 1mm were set, the maximum output power was obtained. The maximum open circuit voltage of 19.4 V was obtained. When the output of the transducers was recetified and filtered through a 1NN5711 Schottky diode bridge rectifier and a 33nF capacitor, the maximum power of 2.05£gW/cm2 was achieved with the load resistance of 5M£[.

This diploma thesis deals with influence of a notch on stress-strain states at the front of cracks by shear modes. Starting with fracture mechanics and its division, followed by stress intensity factor and calculate its by finite element method. Calculation is solved for two types of notches, U-notched and V-notched, both notches were modeled parametrically so their geometry was changeable and stress intensity factor were calculated for all configurations. Subsequently was solved next calculation of stress intensity factor but for shaft without notch. Finally, was evaluated influence of notch on stress intensity factor. Software for finite element method has been used ANSYS. Others calculation was provided in software MATLAB

This thesis presents the design, modeling, and experiment of a novel pressure sensor using a dual-mode AT-cut quartz crystal resonator with beat frequency analysis based temperature compensation technique. The proposed sensor can measure pressure and temperature simultaneously by a single AT-cut quartz resonator. Apart from AT-cut quartz crystal, a newly developed Langasite (LGS) crystal resonator is also considered in the proposed pressure sensor design, since LGS can operate in a higher temperature environment than AT-cut quartz crystal. The pressure sensor is designed using CAD (computer aided design) software and CAE software - COMSOL Multiphysics. Finite element analysis (FEA) of the pressure sensor is performed to analyze the stress- strain of the sensor's mechanical structure. A 3D printing prototype of the sensor is fabricated and the proposed sensing principle is verified using a force-frequency analysis apparatus. Next to the 3D printing model verification, the pressure sensor with stainless steel housing has been fabricated with inbuilt crystal oscillator circuit. The oscillator circuit is used to excite the piezo crystal resonator at its fundamental vibrational mode and give the frequency as an output signal. Based on the FEA and experimental results, it has been concluded that the maximum pressure that the sensor can measure is 45 (psi). The pressure test results performed on the stainless steel product shows a highly linear relationship between the input (pressure) and the output (frequency).

The explosive development of the telecom industry and in particular wireless and mobile communications in recent years has lead to a rapid development of new component and fabrication technologies to continually satisfy the mutually exclusive requirements for better performance and miniaturization on the one hand and low cost on the other. A fundamental element in radio communications is time and frequency control, which in turn is achieved by high performance electro-acoustic components made on piezoelectric single crystalline substrates. The latter, however, reach their practical limits in terms of performance and cost as the frequency of operation reaches the microwave range. Thus, the thin film electro-acoustic technology, which uses thin piezoelectric films instead, has been recently developed to alleviate these deficiencies. This thesis explores and addresses a number of issues related to thin film synthesis on the one hand as well as component design and fabrication on other. Specifically, the growth of highly c-axis textured AlN thin films has been studied and optimized for achieving high device performance. Perhaps, one of the biggest achievements of the work is the development of a unique process for the deposition of AlN films with a mean c-axis tilt, which is of vital importance for the fabrication of resonators operating in contact with liquids, i.e. biochemical sensors. This opens the way for the development of a whole range of sensors and bio-analytical tools. Further, high frequency Lamb wave resonators have been designed, fabricated and evaluated. Performance enhancement of FBAR devices is also addressed, e.g. spurious mode suppression, temperature compensation, etc. It has been demonstrated, that even without temperature compensation, shear mode resonators operating in a liquid still exhibit an excellent performance in terms of Q (200) and coupling (~1.8%) at 1.2 GHz, resulting in a mass resolution better than 2 ng cm-2 in water, which excels that of today’s quartz sensors.

Fracture toughness is an important rock property for rock fracturing and fragmentation applications. Theory and practice of opening mode (mode I) and shearing mode (mode II) fracture toughness tests are still in a developing stage for the cylindrical rock cores. A new circular plate type test specimen is used for mode II fracture toughness testing on rock cores. This involves a straight edge notched circular plate type core disc geometry under three-point bending load / new method and its associated specimen geometry is referred as straight edge notched disc bend (SNDB) specimen under three-point bending. Mode II fracture toughness results of the tests with this new geometry were compared to the results of the tests commonly employed for mode II fracture toughness testing. Specimen geometries were modeled and mode II stress intensity factors were computed by finite element modeling using ABAQUS program. For comparison purposes, mode II or shearing mode fracture toughness KIIc of two different rock types were determined by different testing methods commonly employed in recent practice. Core specimens of Ankara andesite and Afyon marble rock types were tested with cracked chevron notched Brazilian disc and cracked straight through Brazilian disc specimens under Brazilian type loading, semi-circular bend specimen and straight edge notched disc bending specimen geometries under three-point bending.For all testing groups, cylindrical cores with diameters varying from 7.5 cm to 12.5 cm were prepared with notch lengths changing from 1.5 cm to 2.6 cm. Effect of specimen thickness on mode II fracture toughness was investigated for three different testing methods. Fracture toughness values remained constant when thickness of the specimens was increased for cracked straight through Brazilian disc, semi-circular bend and straight notched disc bend methods. For cracked straight through Brazilian disc method KIIc values of Ankara andesite and Afyon marble were 0.99 MPa&radic / m and 0.86 MPa&radic / m, respectively. Mode II fracture toughness with semi-circular bend specimen was 0.43 MPa&radic / m for andesite and 0.46 MPa&radic / m for marble. When the results of the two three-point bending type tests were compared straight notched disc under three-point bending resulted in higher KIIc values (0.61 MPa&radic / m for andesite and 0.62 MPa&radic / m for marble) than the results found by semi-circular bend tests.

The object of this thesis research was to develop and characterize a new type of acoustic biosensor - a ZnO-based laterally excited thickness shear mode (TSM) resonator in a solidly mounted configuration. The first specific aim of the research was to develop the theoretical underpinnings of the acoustic wave propagation in ZnO. Theoretical calculations were carried out by solving the piezoelectrically stiffened Christoffel equation to elucidate the acoustic modes that are excited through lateral excitation of a ZnO stack. A finite element model was developed to confirm the calculations and investigate the electric field orientation and density for various electrode configurations. A proof of concept study was also carried out using a Quartz Crystal Microbalance device to investigate the application of thickness shear mode resonators to cancer biomarker detection in complex media. The results helped to provide a firm foundation for the design of new gravimetric sensors with enhanced capabilities. The second specific aim was to design and fabricate arrays of multiple laterally excited TSM devices and fully characterize their electrical properties. The solidly mounted resonator configuration was developed for the ZnO-based devices through theoretical calculations and experimentation. A functional mirror comprised of W and SiO2 was implemented in development of the TSM resonators. The devices were fabricated and tested for values of interest such as Q, and electromechanical coupling (K2) as well as their ability to operate in liquids. The third specific aim was to investigate the optimal surface chemistry scheme for linking the antibody layer to the ZnO device surface. Crosslinking schemes involving organosilane molecules and a phosphonic acid were compared for immobilizing antibodies to the surface of the ZnO. Results indicate that the thiol-terminated organosilane provides high antibody surface coverage and uniformity and is an excellent candidate for planar ZnO functionalization. The fourth and final specific aim was to investigate the sensitivity of the acoustic immunosensors to potential diagnostic biomarkers. Initial tests were performed in buffer spiked with varying concentrations of the purified target antigen to develop a dose-response curve for the detection of mesothelin-rFc. Subsequent tests were carried out in prostate cancer cell line conditioned medium for the detection of PSA. The results of the experiments establish the operation of the devices in complex media, and indicate that the acoustic sensors are sensitive enough for the detection of biomolecular targets at clinically relevant concentrations.

Les ondes acoustiques et électromagnétiques offrent des méthodes de caractérisation des matériaux très peu invasives. Souvent utilisées à l'aide de capteurs indépendants, l'approche développée ici est de proposer un résonateur multimodal acoustique et électromagnétique. Afin de répondre à une grande variété d'applications, le choix de l'élément actif piézo-électrique s'est porté sur un disque de quartz de coupe AT. L'étude s'articule autour des étapes aboutissant in fine à un capteur magnéto acoustique on-chip à excitation sans contact.L'étude théorique d'un capteur magnéto-acoustique à excitation inductive est tout d'abord réalisée pour un capteur chargé par un fluide visqueux. Ce capteur est constitué de trois éléments : une sonde radiofréquence (RF), un résonateur RF à fort facteur de qualité et le quartz sur lequel ont été déposées deux électrodes en anneau. Cette étude montre comment déduire la viscosité complexe du matériau étudié à partir de l'impédance électrique du système complet. Les mesures effectuées sur des mélanges étalons montrent une très bonne correspondance avec les résultats théoriques.L'intégration du résonateur RF sur l'élément piézo-électrique s'effectuant via des électrodes circulaires, une étude préliminaire est menée sur les ondes acoustiques pouvant être générées sur le quartz et leur interaction avec les électrodes. Les mesures de vibration par vibrométrie laser montrent que des ondes de Lamb sont générées dans une large gamme de fréquence (de 100 kHz à 20 MHz). L'analyse de la réponse impulsionnelle spatiale par transformée de Gabor 3D localise la source de ces ondes sur le bord des électrodes. Par ailleurs, l'étude du disque au fondamental montre une grande non-linéarité mécanique du quartz.Le modèle de résonateur RF plan multi-tour puis son intégration sur le disque de quartz du capteur magnéto-acoustique on-chip sont ensuite étudiés. Les résultats expérimentaux par mesure d'impédance et vibrométrie laser valident le modèle. La gamme de fréquence sélectionnée (entre 5 et 20 MHz) permet d'envisager des mesures micro-rhéologiques. / Acoustic and electromagnetic waves are key probing candidates for characterizing their propagation media with minimum perturbation. Often used with independent sensors based on specialized transducing materials, the approach developed here provides an on-ship multimodal sensor using the same sensing material for probing the acoustic and electromagnetic properties of the material. To meet a wide range of applications, the choice of the active piezoelectric element is carried out on an AT cut quartz. The study focuses on the steps leading in fine to an on-chip magneto-acoustic sensor with a contactless excitation.The theoretical study of a magneto-acoustic sensor inductively excited and loaded by a viscous fluid is first carried out. This sensor consists of three elements: a radio frequency (RF) sensor, a high quality factor RF resonator and a quartz on which two ring electrodes have been deposited. The complex viscosity of the studied material is derived from the electrical impedance of the complete system. The measurements carried on etalon viscoelastic materials show a good agreement with the theoretical results.The integration of the RF resonator on the piezoelectric element being via circular electrodes, a preliminary study is performed for determining the acoustic waves that can be generated in the quartz and their interaction with the electrodes. The laser vibrometry measurements indicate that Lamb waves are generated in a wide frequency range, from 100 kHz to 20 MHz. The analysis of the spatial pulse response of the sensor surface by 3D Gabor transform locates the source of these waves on the edge of the electrodes. Furthermore, the study of the disk at it fundamental frequency points out the high nonlinear mechanical behavior of the quartz.The plane RF multi-turn resonator and its integration on the quartz disk of the magneto-acoustic on-chip sensor are then studied. The experimental results of impedance and laser vibrometry measurements validate the proposed theoretical model. The selected frequency range (between 5 and 20 MHz) allows one to consider micro rheological measurements.

This study embarks on exploiting the Thickness Shear Mode (TSM) acoustic wave sensor and the ElectroMagnetic Piezoelectric Acoustic Sensor (EMPAS) towards the study of aptamer-to-cocaine binding in a label-free direct approach. The high sensitivity and selectivity offered by the EMPAS in combination with alkyltrichlorosilane-based self-assembled monolayers proved superior towards the detection of cocaine. The most efficient method for the attachment of the aptamers onto the sensor surface to construct highly dense populations of the aptamer molecules with retained biomolecule activity is shown to be dependent on the composition of immobilizing solution and on the amount of spacing provided in the plane of the aptamer molecules. The distinct ligand-induced binding mechanisms and regeneration capabilities of the two anti-cocaine aptamers are monitored with the EMPAS. Utilizing this sensor to monitor cocaine-aptamer interactions will serve as the first piezoelectric aptasensor for the detection of a small molecule.