Mechanical Engineering Commons^™

Photonic Sensors Based On Integrated Ring Resonators, Jaime Da Silva

Mechanical Engineering Research Theses and Dissertations

This thesis investigates the application of integrated ring resonators to different sensing applications. The sensors proposed here rely on the principle of optical whispering gallery mode (WGM) resonance shifts of the resonators. Three distinct sensing applications are investigated to demonstrate the concept: a photonic seismometer, an evanescent field sensor, and a zero-drift Doppler velocimeter. These concepts can be helpful in developing lightweight, compact, and highly sensitive sensors. Successful implementation of these sensors could potentially address sensing requirements for both space and Earth-bound applications. The feasibility of this class of sensors is assessed for seismic, proximity, and vibrational measurements.

Design And Nonlinear Control Of A Haptic Glove For Virtual Palpation, Matthew Galla

Mechanical Engineering Research Theses and Dissertations

This dissertation presents the design, kinematic analysis, and nonlinear control of a Haptic Glove for medical elastographic imaging virtual palpation. Of the 13 degrees of freedom present in the index finger, middle finger, and thumb of the hand, the design fixes 4, constrains 2 and controls 6 with pneumatic air cylinder actuators, allowing uncontrolled, but measured motion in the remaining 1 degree of freedom. Nearly linear bijective transfer functions between the actuator positions and joint angles are found in closed form for all 6 actuated joints. A nonlinear, sliding-mode controller that allows each actuator to be controlled by a single …

Magnetic Gradient-Based Magnetic Tweezer System For 3d And Swarm Control Of Microswimmer, Xiao Zhang

Mechanical Engineering Research Theses and Dissertations

Microscale manipulation has very promising potential in medical applications such as drug delivery, minimal and invasion surgery. Contactless control is preferable as remote manipulation is necessary for in vivo applications. Among different control methods, magnetic power source is more suitable and robust for the applications mentioned above. Presented here is a magnetic tweezer system, which manipulates microscale magnetic particles using magnetic forces created by magnetic field gradient. The proposed system has three advantages: First, force applied by the magnetic tweezer system does not contact with the target object and can be generated in different directions. Second, the magnetic tweezer system …

Actuation And Control Methods For Individual And Swarm Multiscale Mechanical Systems, Pouria Razzaghi

Mechanical Engineering Research Theses and Dissertations

Robotic mechanisms can be driven by different internally and externally applied inertial and magnetic actuations. These actuations are utilized to regulate the dynamics of robots and move them in different locomotion modes. The first part of this dissertation is about using an external magnetic actuation to move a simple-in-design, small-scale robot for biomedical applications. The robots can be steered in different locomotion modes such as pivot walking and tumbling. The control design of this system consists of a swarm algorithm under a global control input, and a vision-based closed-loop controller to navigate in 2D environments.

Secondly, I propose a new …

Microparticle Propulsion For In Vivo Navigation, Louis Rogowski

Mechanical Engineering Research Theses and Dissertations

Microscale propulsion impacts a diverse array of fields, with simplistic microrobots allowing for novel innovations in microscale surgery and drug delivery. Propulsion at the microscale is constrained by physics, with time-reversal and geometric symmetries limiting available propulsion mechanisms. However, certain fluid environments and surface coatings allow for the propulsion of microparticles through externally applied magnetic fields. Presented here is a detailed analysis of microparticles propelling using spontaneous symmetry breaking, flagella surface coatings, and multi-modal actuation mechanisms. Spontaneous symmetry breaking in nonlinearly viscoelastic fluids is presented for the first time in literature, with two equal and opposite propulsion states existing along …

Wireless Wearable System For The Assessment Of Gait, Abdallah Jabr

Mechanical Engineering Research Theses and Dissertations

This work investigates the development and use of a wireless wearable system for the assessment of gait. The system proposed consists of a sensor module that is attached to the foot. The sensor proposed is an inertial measurement unit, often abbreviated as IMU - a 9-axis System in Package (SiP) including a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis magnetometer, as well as a fusion engine for signal processing. While the focus of this work is on evaluating gait metrics, the performance of the proposed IMU in evaluating orientation is quantified. In doing this work, we try to address …

Application Of Optimal Switching Using Adaptive Dynamic Programming In Power Electronics, Ataollah Gogani Khiabani

Mechanical Engineering Research Theses and Dissertations

In this dissertation, optimal switching in switched systems using adaptive dynamic programming (ADP) is presented. Two applications in power electronics, namely single-phase inverter control and permanent magnet synchronous motor (PMSM) control are studied using ADP. In both applications, the objective of the control problem is to design an optimal switching controller, which is also relatively robust to parameter uncertainties and disturbances in the system. An inverter is used to convert the direct current (DC) voltage to an alternating current (AC) voltage. The control scheme of the single-phase inverter uses a single function approximator, called critic, to evaluate the optimal cost …

Control And Locomotion Of Inertially And Magnetically Actuated Multi-Scale Robotic Systems, Ehab Al Khatib

Mechanical Engineering Research Theses and Dissertations

In this research, two actuation systems were introduced, inertial and magnetic actuation. In the inertial actuation, the robot used the transfer of momentum to navigate, and this momentum could be generated by spinning masses and wheels. Recent studies in our System Laboratory proved that a wide range of inertially actuated locomotion systems could be generated. This can be achieved by using a family tree approach, starting from a very simple system, and progressively evolving it to more complex ones. The motion diversity of these robots inspired us to extend their locomotion from a macro scale to millimeter and micro scales. …

Investigation Of Fundamental Principles Of Rigid Body Impact Mechanics, Khalid Alluhydan

Mechanical Engineering Research Theses and Dissertations

In impact mechanics, the collision between two or more bodies is a common, yet a very challenging problem. Producing analytical solutions that can predict the post-collision motion of the colliding bodies require consistent modeling of the dynamics of the colliding bodies. This dissertation presents a new method for solving the two and multibody impact problems that can be used to predict the post-collision motion of the colliding bodies. Also, we solve the rigid body collision problem of planar kinematic chains with multiple contacts with external surfaces.

In the first part of this dissertation, we study planar collisions of Balls and …

Optical Micro-Seismometer Based On Evanescent Field Perturbation Of Whispering Gallery Modes, Jaime Da Silva

Mechanical Engineering Research Theses and Dissertations

This thesis proposes a light-weight, compact, and accurate optical micro-seismometer that could be used in many applications, such as planetary exploration. The sensor proposed here is based on the principle of whispering gallery optical mode (WGM) resonance shifts of a dielectric micro-resonator due to disturbances of its evanescent field. The micro-seismometer could be used in place of the traditional bulky seismometers. The design of a waveguide-resonator and mechanical structure to disturb the evanescent field are presented. A proof-of-concept a seismometer model that uses a 5µm ring resonator is numerically tested with actual seismic data. The results show that a WGM-based …

Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, Samuel Sheckman

Mechanical Engineering Research Theses and Dissertations

In this work, the approach to the manipulation of alginate artificial cell soft-microrobots, both individually and in swarms is shown. Fabrication of these artificial cells were completed through centrifugation, producing large volumes of artificial cells, encapsulated with superparamagnetic iron oxide nanoparticles; these artificial cells can be then externally stimulated by an applied magnetic field. The construction of a Permeant Magnet Stage (PMS) was produced to manipulate the artificial cells individually and in swarms. The stage functionalizes the permanent magnet in the 2D xy-plane. Once the PMS was completed, Parallel self-assembly (Object Particle Computation) using swarms of artificial cells in complex …

A Microresonator-Based Laser Doppler Velocity Sensor For Interplanetary Atmospheric Re-Entry, Benjamin Wise

Mechanical Engineering Research Theses and Dissertations

In this thesis, a laser velocity sensor concept based on optical microresonators is presented and the application to spacecraft atmospheric entry is explored. The concept is based on the measurement of Doppler shift of back-scattered laser light. Specifically, the Doppler shift is detected by observing the whispering gallery optical modes (WGM) of a dielectric microresonator excited by the back scattered light from particulates and gas molecules. The microresonator replaces the typical Fabry-Perot interferometer and CCD camera system, thereby significantly reducing the size and weight of the overall detection system. This thesis presents proof-of-concept results for this measurement approach. The Doppler …