The goal of this thesis is to develop a soft multiple-degree-of-freedom (multi-DOF) load cell that is robust and light weight for use in robotics applications to sense three axes of force and a single axis of torque. The displacement of the magnet within the elastomer changes the magnetic flux density which is sensed by two 3-axis Hall effect sensors. Experimental measurements of magnetic flux density within the area of interest were used to formulate analytic expressions that relate magnet field strength to the position of the magnet. The displacement and orientation measurement and the material properties of the elastomer are used to calibrate and calculate the applied load. The ability to measure 3-DOF force and axial torque was evaluated with combined loading applied by a robotic arm (KUKA, LBR r820 iiwa). The decoupled results show the 4-DOF load cell was able to distinguish 3-axis force and 1-axis torque with 6.9% averaged error for normal force, 4.3% and 2.6% for shear force in the X and Y axis and 8.6% for the torque. The results show good accuracy for a soft multi-axis sensor that would be applicable in many robotic applications where high accuracy is not required.

Cancer metastasis, the departure of cancer cells from the primary tumors and their spread to distant sites, is responsible for 90% of cancer related deaths. Thus, understanding the initial process which leads to cancer metastasis in the later stage and stopping the spread in the initial stage deems necessary. In spite of significant progress in diagnosis and treatment, there is still the need for robust and easy to use drug assessment methods. In this work we present two approaches for this purpose: a microengineered Boyden chamber, and a dielectrophoresis-based platform for cell characterization and drug assessment. Using these methods, we characterize the drug response of breast cancer, which is the second most common type of cancer among US women. The micorengineered Boyden chamber we designed in this work is made of a silicon-based transmigration well with a 30µm-thick membrane and 8µm pores. This platform includes a deep microfluidic channel on the back-side sealed with a glass wafer. Using this platform, the migratory behavior of highly metastatic breast cancer cells, MDA-MB231, is tested under different drug treatment conditions. The second platform, the off-chip passivated electrode insulator-based dielectrophoresis (OπDEP) device, has been used to first distinguish between different breast cancer cell lines namely LCC1/MCF7, LCC9/MCF7, MCF7, and MDA-MB231, and also to probe the effect of different drug treatments on the cells. These versatile platforms will enable the enhanced integration with other technologies and running multiple assays simultaneously. Moreover, the methods presented show potential for next generation drug discovery and patient follow up purposes. / Master of Science

This paper presents a multidegrees-of-freedom non-linear multibody dynamic model of a vehicle, comprising front and rear suspensions, steering system, road wheels, tyres and vehicle inertia. The model incorporates all sources of compliance, stiffness and damping, all with non-linear characteristics. The vehicle model is created in ADAMS (automatic dynamic analysis of mechanical systems) formulation. The model is used for the purpose of vehicle handling analysis. Simulation runs, in-line with vehicle manoeuvres specified under ISO and British Standards, have been undertaken and reported in the paper.

This dissertation presents novel vibrational control strategies for mechanical control-affine systems with high-frequency, high-amplitude inputs. Since these control systems use high-frequency, zero-mean, periodic inputs, averaging techniques are widely used in the analysis of their dynamics. By studying their time-averaged approximations, new properties of the averaged dynamics of this class of systems are revealed. Using these properties, the problem of input optimization of vibrational control systems was formulated and solved by transforming the problem to a constrained optimization one. Geometric control theory provides powerful tools for studying the control properties of control-affine systems. Using the concepts of vibrational and geometric controls and averaging tools, a closed-loop control strategy for trajectory tracking of a class of underactuated mechanical control-affine systems is developed. In the developed control law, the fact that for underactuated systems, the actuated coordinates together with the corresponding generalized velocities can be considered as generalized inputs for the unactuated dynamics plays the main role. Using the developed control method, both actuated and unactuated coordinates of the system are able to follow slowly time-varying prescribed trajectories on average. The developed control method is applied for altitude control of flapping wing micro-air vehicles by considering the sweeping (flapping) angle of the wings as the inputs. Using the feathering (pitch) angles of the wings as additional inputs, and using non-symmetric flapping, the control method is then extended for three-dimensional flight control of flapping wing micro-air vehicles. / Ph. D.

The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters. A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance Cp and resistance Rp can be calculated at a frequency of 1 mHz to 1 Hz. This method demonstrates that for pyroelectric materials the impedance depends on two major factors: average working temperature, and the heating rate. Design and implementation of a hybrid approach using multiple piezoelectric cantilevers is presented. This is done to achieve mechanical and electrical tuning, along with bandwidth widening. In addition, a hybrid tuning technique with an improved adjusting capacitor method was applied. An toroid inductor of 700 mH is shunted in to the load resistance and shunt capacitance. Results show an extended frequency range up to 12 resonance frequencies (300% improvement) with improved power up to 197%. Finally, a hybrid piezoelectric and pyroelectric system is designed and tested. Using a voltage doubler, circuit for rectifying and collecting pyroelectric and piezoelectric voltages individually is proposed. The investigation showed that the hybrid energy is possible using the voltage doubler circuit from two independent sources for pyroelectrictity and piezoelectricity due to marked differences of optimal performance.

O objetivo desse trabalho foi desenvolver um equipamento destinado a proporcionar a realização de exercícios terapêuticos, baseado numa abordagem sistemática de desenvolvimento de projeto orientado pelo usuário e obter um protótipo funcional. Por meio das técnicas de metodologia de projeto e dos fundamentos gerais de elementos de máquinas desenvolveram-se a fase do projeto conceitual, com interface ao projeto informacional de Souza (2016), e do projeto preliminar direcionado ao desenvolvimento de um protótipo funcional destinado à sustentação e movimentação dos membros superiores de indivíduos com disfunções motoras nos nestes membros. Devido a um conjunto de fatores provenientes dos mais diversos segmentos da sociedade, há uma demanda crescente com relação à atuação das diversas áreas da engenharia, que possam fornecer soluções tecnicamente viáveis e ainda, com um grau de personalização em massa destinadas às aplicações na área da saúde. A área de conhecimento denominada \"Tecnologia Assistiva\" (TA) inserida na área da saúde, atua principalmente no desenvolvimento de órteses, próteses e auxílio à mobilidade, desenhando fronteiras com questões de acessibilidade, com uso e adequação de produtos, bem como na atuação de áreas de habilitação e reabilitação promovendo qualidade de vida e inclusão social de indivíduos com algum tipo de deficiência ou mobilidade reduzida. Nesse trabalho, o uso de ferramentas de metodologia de projeto durante as discussões sobre o projeto informacional e a implementação do projeto conceitual, ambos de caráter interdisciplinar, permitiu estabelecer a interface entre decisões técnicas de engenharia e os requisitos do usuário. O usuário intermediário, responsável pela prescrição e avaliação do protótipo foi representado por uma amostra de terapeutas ocupacionais, que acompanharam o processo de desenvolvimento do projeto até a validação do protótipo funcional. Os resultados obtidos nesse trabalho foram: obtenção de uma lista de requisitos do usuário, que convertida em um conjunto de características técnicas permitiu o desenvolvimento do projeto orientado pelo usuário (Terapeutas Ocupacionais) e construção de um protótipo funcional. O equipamento de apoio aos exercícios terapêuticos proposto apresenta graus de inovação, quando comparado à equipamentos comerciais e patentes, principalmente: adequação à diferentes mobiliários em ambiente hospitalar e doméstico (camas, cadeiras, mesas); melhor processo de compactação do equipamento para armazenagem e transporte, feito por uma única pessoa; exercícios com os membros superiores: uni e bilateral e abertura completa dos membros superior no plano coronal por meio de guias lineares. / This work presented the development of an apparatus whose objective is allow the therapeutic exercises, based on a systematic approach user-oriented design development, and fabricate a functional prototype. Based on design methodology and machine elements theory it was developed the conceptual and the preliminary design phase, based on the informational design phase of Souza (2016), to develop a functional prototype aimed to provide support and movement of the upper limbs of people with motor dysfunction in these members. Due to a range of factors from the various segments of society, there is increasing demand related to the performance of various areas of engineering, that can provide technically feasible solutions and with a degree of mass customization intended for applications in the health area. The knowledge area of \"Assistive Technology\" (AT) is inserted in the health area and acts mainly in the development of prostheses, orthoses and aid mobility, by drawing borders with accessibility issues, using and adjusting products, in addition to acting in habilitation and rehabilitation areas, which promote quality of life and social inclusion of individuals with a disability or reduced mobility. In this work, the use of design methodology tools during the discussion on the informational design and implementation of conceptual design, both interdisciplinary, revealed the interface between technical engineering decisions and user requirements. The intermediate user, responsible for evaluating the prototype was represented by sample occupational therapists, which prescribes and follows up the use of the mechanisms and/or equipment to end users. The main result of this work was a better definition of the user requirements that allowed obtaining design parameters focusing on occupational therapists as well as the development of a functional prototype. The main technical characteristics obtained through of the interactive and iterative processes along the informational, conceptual and preliminary design phases both prototype validation were: compaction of the device (related to storage and use for one or both arms of the user). Besides, the equipment allows possibility of adaptation to different furniture and environments: hospital, clinics, small treatment rooms, domestic bed, and chairs and use; rehabilitation exercises with positions of the upper limbs: uni- and bilateral and total movement of the upper limbs on coronal plane based on linear guides.

A ventilação mecânica pulmonar é a substituição da respiração espontânea de um paciente quando este não realiza ou realiza parcialmente esta tarefa. Esta ventilação é de extrema importância para o tratamento de pacientes em estado crítico em unidades de terapia intensiva e para a manutenção da oxigenação sanguínea durante cirurgias. A ventilação mecânica pulmonar consiste em empurrar os gases para dentro do pulmão de forma controlada, mantendo uma pressão inspiratória ou um volume inspiratório determinado. Além disso, controla o nível de pressão durante a expiração do paciente para manter os alvéolos abertos e dificultar lesões internas. Este trabalho se propõe a caracterizar uma especificação de engenharia para os sistemas de controle de ventilação, se baseando em características fisiológicas do sistema respiratório do paciente saudável e também com patologias conhecidas. São apresentados modelos matemáticos para os sistemas mecânicos responsáveis pela atuação na inspiração e na expiração do paciente, bem como um modelo matemático para o sistema respiratório. Foram desenvolvidos sistemas de controle, baseados no controlador PID, para os principais tipos de modalidades ventilatórias. Os sistemas controlados foram simulados e os resultados são apresentados neste trabalho. Os controles propostos foram implementados em equipamentos de anestesia e UTI projetados na K. Takaoka Ind. Com. Prod. Hosp. LTDA. entre 2008 e 2010 no Brasil, e estão sendo usados hoje nas salas de cirurgia e centros de terapia intensiva pelo Brasil e em alguns países da América do Sul e do Oriente médio. / The mechanical ventilation is the replacement of spontaneous breathing of a patient when it does not perform or partially perform this task. This ventilation is extremely important for the treatment of critically ill patients in intensive care units and for the maintenance of blood oxygenation during surgery. The mechanical ventilation consists in pushing the gas into the lungs in a controlled manner, maintaining a determined inspiratory pressure or inspiratory volume. In addition, it has to control the pressure level during the patients exhalation to keep the alveoli opened and prevent internal injuries. This work aims to characterize an engineering specification for the control systems of ventilation, relying on physiological characteristics of the patient\'s respiratory system on healthy subjects and also subjects with known diseases. Here are presented mathematical models for the mechanical systems responsible for acting on the inspiration and expiration of the patient, as well as a mathematical model for the respiratory system. There were developed control systems, based on the PID controller for the main types of ventilation modes. Controlled systems were simulated and the results are presented in this dissertation. The proposed controls were implemented in anesthesia and intensive care equipments designed in K. Takaoka Ind. Com Prod. Hosp. LTD. between 2008 and 2010 in Brazil, and are being used today in the operating rooms and intensive care centers in Brazil and some countries in South America and the Middle East.

The goal of this work was to compensate for the effects of the Earth’s magnetic field in a vector field magnetic sensor. The magnetic sensor is a part of a low-cost crash avoidance system by Stephane Roussel where the magnetic sensor was used to detect cars passing when it was mounted to a test vehicle. However, the magnetic sensor’s output voltage varied when it changed orientation with respect to the Earth’s magnetic field. This limited the previous work to only analyze detection rates when the test vehicle travelled a single heading. Since one of the goals of this system is to be low-cost, the proposed solution for geomagnetic compensation will only use a single magnetic sensor and a consumer-grade GPS. Other solutions exist for geomagnetic compensation but use extra sensors and can become costly. In order to progress the development of this project into a commercial project, three separate geomagnetic compensation algorithms and a calibration procedure were developed. The calibration procedure compensated for the local magnetic field when the magnetic sensor was mounted to the test vehicle and allowed for consistent magnetic sensor voltage output regardless of the type of test vehicle. The first algorithm, Compensation Scheme 1 (CS1), characterized the local geomagnetic field with a mathematical function from field calibration data. The GPS heading was used as the input and the output is the voltage level of the Earth’s magnetic field. The second algorithm, Compensation Scheme 1.5, used a mathematical model of the Earth’s magnetic field using the International Geomagnetic Reference Field. An algorithm was developed to take GPS coordinates as an input and output the voltage contributed by the mathematical representation of the Earth’s magnetic field. The output voltages from CS1 and CS1.5 were subtracted from the calibrated magnetic sensor data. The third algorithm, Compensation Scheme 2 (CS2), used a high pass filter to compensate for changes of orientation of the magnetic sensor. All three algorithms were successful in compensating for the geomagnetic field and vehicle detection in multiple car headings was possible. Since the goal of the magnetic sensor is to detect vehicles, vehicle detection rates were used to evaluate the effectiveness of the algorithms. The individual algorithms had limitations when used to detect passing cars. Through testing, it was found that CS1 and CS1.5 algorithms were suitable to detect vehicles while stopped in traffic while the CS2 algorithm was suitable vehicle detection while the test vehicle is moving. In order to compensate for the limitations of the individual algorithms, a fused algorithm was developed that used a combination of CS1 and CS2 or CS1.5 and CS2. The vehicle speed was used in order to determine which algorithm to use in order to detect cars. Although the goal of this project is not vehicle detection, the rate of successful vehicle detection was used in order to evaluate the algorithms. The evaluation of the fused algorithm demonstrated the value of using CS1 and CS1.5 to detect vehicles when stopped in traffic, which CS2 algorithm cannot do. For a study conducted in traffic, using the fused algorithm increased vehicle detection rates by 51%-62% from using the CS2 algorithm alone. Since this work successfully compensated for geomagnetic effects of the magnetic sensor, the low-cost crash avoidance system can be further developed since it is no longer limited to driving in a single direction. Other projects that experience unwanted geomagnetic effects in their projects can also implement the knowledge and solutions used in this work.

Mechanical durability of the structures should be continuously monitored during their operation. Structural health monitoring (SHM) techniques are typically used for gathering the information which can be used for evaluating the current condition of a structure regarding the existence, location, and severity of the damage. Damage can occur in a structure after long-term operating under service loads or due to incidents. By detection of these defects at the early stages of their growth and nucleation, it would be possible to not only improve the safety of the structure but also reduce the operating costs. The main goal of this dissertation is to develop a reliable and cost-effective SHM system for inspection of composite and metallic structures. The Surface Response to Excitation (SuRE) method is one of the SHM approaches that was developed at the FIU mechatronics lab as an alternative for the electromechanical impedance method to reduce the cost and size of the equipment. In this study, firstly, the performance of the SuRE method was evaluated when the conventional piezoelectric elements and scanning laser vibrometer were used as the contact and non-contact sensors, respectively, for monitoring the presence of loads on the surface. Then, the application of the SuRE method for the characterization vii of the milling operation for identical aluminum plates was investigated. Also, in order to eliminate the need for a priori knowledge of the characteristics of the structure, some advanced signal processing techniques were introduced. In the next step, the heterodyne method was proposed, as a nonlinear baseline free, SHM approach for identification of the debonded region and evaluation of the strength of composite bonds. Finally, the experimental results for both methods were validated via a finite element software. The experimental results for both SuRE and heterodyning method showed that these methods can be considered as promising linear and nonlinear SHM approaches for monitoring the health of composite and metallic structures. In addition, by validating the experimental results using FEM, the path for further improvement of these methods in future researches was paved.

Since the proliferation of CAD tools, visualizations have gained importance.. They provide invaluable visual feedback at the time of design, regardless whether it is fbi civil engineering or electronic circuit design-layout. Typically dynamic visualizations are produced in a two phase process: the calculation of positions and rendering of the image and its presentation as an animated video clip. This is a slow process that is unsuitable fbr interactive CAD visualizations, because the former two require finite element analysis Faster hardware eases the problem, but does not overcome it, because the algorithms are still too slow. Our MEMS CAD project works towards methods and techniques that are suitable for interactive design, with faster methods. The purpose of this PhD thesis is to contribute to the design of an interactive virtual prototyping of Micro Electro Mechanical Systems (MEMS) This research comprises the analysis of the visualization techniques that are appropriate for these tasks and identifying the difficulties that need to be overcome to be able to offer a MEMS design engineer a meaningful and interactive CAD design environment Such a VR-CAD system is being built in our research group with many participants in the team. Two particular problems are being addressed by presenting algorithms for truthful VR visualization methods: one is for displaying objects that are different in size on the computer screen. The other is modelling unsynchronized motion dynamics, that is different objects moving simultaneously at very high and vety low speed, by proposing stroboscopic simulation to present their dynamics on the screen They require specific size scaling and time scaling and filtering. It is these issues and challenges which make the design of a MEMS CAD tool different from other CAD tools. In the thesis I present algorithms for displaying animated virtual reality for MEMS virtual prototyping in a physically truthful way by using the simulated stroboscopic illumination to filter animated images to make it possible to show unsynchronized motion.. A scaling method was used to show or hide objects which cannot be shown simultaneously on the computer screen because of their large difference in size. The visualization of objects being designed and their animations is done with much consideration of visual perception and computer capability, which is rising attention, but not too often mentioned in the visualization domain.