Engineering Commons^™

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 …

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 …

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 …

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 …

Blunt And Ballistic Impacts On Human Head Models: An Analytical And Numerical Study, Yongqiang Li

Mechanical Engineering Research Theses and Dissertations

Head injuries, as a leading cause of death, have become a major health care issue for civilians and soldiers. There has been an urgent need to understand mechanisms of such injuries. The objective of this dissertation research is to study some head injuries and related mechanisms using analytical and computational models.

In Chapter 2, a new analytical (non-linear) model for the impact of a solid sphere on a fluid-filled spherical shell is developed by including the stress wave propagation effect in addition to the Hertzian contact deformations and the shell membrane and bending actions. A simplified (linearized) model incorporating the …

Multiple Consecutive Recapture Of Rigid Nanoparticles Using A Solid-State Nanopore Sensor, Jungsoo Lee

Mechanical Engineering Research Theses and Dissertations

Solid‐state nanopore sensors have been used to measure the size of a nanoparticle by applying a resistive pulse sensing technique. Previously, the size distribution of the population pool could be investigated utilizing data from a single translocation, however, the accuracy of the distribution is limited due to the lack of repeated data. In this study, we characterized polystyrene nanobeads utilizing single particle recapture techniques, which provide a better statistical estimate of the size distribution than that of single sampling techniques. The pulses and translocation times of two different sized nanobeads (80 nm and 125 nm in diameter) were acquired repeatedly …

Cancer Diagnosis By Bioimpedance Spectroscopy And Computer-Assisted Pattern Recognition, Shahriar Shams

Mechanical Engineering Research Theses and Dissertations

The field of cancer diagnostics has always been one of the most complex and challenging areas in biomedical research, and there has been an increasing demand for more advanced clinical diagnostic equipment over the past four decades. In this thesis, a custom-made coaxial bioimpedance sensor was used, in combination with computer-aided pattern recognition tools, to identify cancer in tissue samples obtained from the formalin-fixed kidney of a 60 year-old male patient. Impedance data was collected using the coaxial sensor at 401 logarithmically-spaced frequency points ranging from 10 kHz to 100 MHz. Principle Component Analysis and Naive Bayes Classification techniques were …