Engineering Commons^™

Design, Fabrication, And Testing Of A 3d Printer Based Microfluidic System, Carlton A. Mcmullen

Graduate Theses and Dissertations

A pneumatically actuated PDMS based microfluidic devices were designed and fabricated by soft-lithography. Two types of molds were fabricated out of different material for this experiment. The first mold, (device 1), was fabricated from a sheet of Polymethyl methacrylate (PMMA) material, similar to Plexiglas. The device features were micro-engraved onto the face of the material. The second mold, (device 2), was fabricated from the use of fused deposition modeling (FDM) 3D printing. The pumping efficiency of the PDMS devices was analyzed through the characterization of the micro-pumps flowrate with respect to the pumps driving pressure and the actuation frequency. Tested …

Heat-Driven Self-Cooling System Based On Thermoelectric Generation Effect, Robel Kiflemariam

FIU Electronic Theses and Dissertations

This research entails the first comprehensive and systematic study on a heat-driven, self-cooling application based on the thermoelectric generation effect. The system was studied using the first and second laws of thermodynamics to provide a solid and basic understanding of the physical principles governing the system. Multiphysics equations that relate heat transfer, fluid dynamics and thermoelectric generation are derived. The equations are developed with increasing complexity, from the basic Carnot heat engine to externally and internally irreversible engines. A computational algorithm to systematically use the fundamental equations has been presented and computer code is implemented based on the algorithm.

Experiments …

Skyport: Payload: Medical Cooler For The Skyport Uav, Madison Gee, Hector Lopez, Victor Magaña

Mechanical Engineering Senior Theses

Access to basic healthcare is a major persisting problem around the globe, especially in rural parts of the world. One of the many facets of this problem is access to vaccine treatment. The transportation and storage of vaccines at the proper temperature is an issue that is still being solved and improved upon today. One of the common solutions to this problem is the use of passive coolers such as ice packs and other refrigerants. The potential issue with passive cooling is that the temperature cannot be actively controlled. This is evident, as many vaccines are wasted due to incorrect …

Skyport Airframe: Design And Manufacturing, Thomas Clark, Michael Dewane, Siosiua Faleta, Robert Llanos-Hinson

Mechanical Engineering Senior Theses

Many rural areas of developing countries lack the necessary transportation infrastructure to have reliable access to basic needs. This is particularly true for medical supplies. To combat the issue of insufficient access to vaccines in developing areas, the SkyPort project has developed the SkyPort UAV (Unmanned Aerial Vehicle). The SkyPort UAV has the vertical takeoff and landing (VTOL) capabilities of a quadcopter, as well as the efficient, sustained flight of a fixed-wing aircraft. It provides a cheaper, quicker, and safer delivery method than existing alternatives for vaccines in areas that lack a reliable transportation infrastructure. The role of the SkyPort …

Automated In-Row Weed Trimmer, Joshua Baculi, Tyler Castrucci, Joshua Ding, Marit Knapp, Gaston Young

Mechanical Engineering Senior Theses

The Automated In-Row Weed Trimmer, or AIRWT, is a weed removal system designed to be used in vineyards in order to enable safe and e cient removal of weeds while preventing damage to the vines. The goal of the system is to reduce the need for the use of manual labor and herbicides while improving production rates of grapes by automating the weed removal process at vineyards. By implementing an automated system for weed removal, the team aims to resolve ethical issues in food production, primarily those surrounding human labor, environmental friendliness, and social sustainability. The focus of this report …

Sunplanter, Matthew Diaz, Joseph Gaither, Stephen Hight, J. Brandon Suehiro

Mechanical Engineering Senior Theses

Although the cost of solar technology has been reduced by nearly seventy percent in the last ten years, the cost of implementing solar panels for residential and commercial use has remained stagnant. Due to the lack of affordable, easily installable solar panel systems on residential properties, the goal of our Senior Design Project is to design a stand-alone solar tracking structure. Since the system is stand-alone, it can be easily implemented on a wide range of properties in most areas of California. Our design for the support of the solar tracking system is a two-pole structure, with a wide base …

Legacy Borehole Project, Piper Connelly, Rhys Marks, Ronald Saavedra

Mechanical Engineering Senior Theses

To assist scientists in their pursuit of important research of the subseafloor, the Legacy Borehole Project designed a unique structure that will be lowered to the ocean floor for data collection beneath the ocean floor. This derrick structure will provide support for a sensor package to access pre-existing boreholes, deep and narrow holes drilled into the Earth's crust beneath the sea floor. Our team has completed the second year effort of the three-year plan. In this paper we detail our work on the structure, which will be assembled on a ship's deck and lowered onto the borehole reentry cone with …

Rsl Autonomous Rover, Cris Madrigal, Jiachi Zhang, Nicholas Peacock, Brogan O'Hara

Interdisciplinary Design Senior Theses

Autonomous vehicles are useful for a variety of applications such as military, urban, and agricultural environments. This paper discusses adding an autonomous navigation system to an all-terrain vehicle by implementing controllers that interface with its current system, installing sensors on the vehicle for obstacle detection, and developing effective safety mechanisms to prevent injury to others. The result is a vehicle capable of waypoint navigation and obstacle avoidance. Testing the vehicle showed that the LIDAR and the autonomous navigation system were integrated seamlessly, and that the sensor output signals were successfully translated into vehicle commands the existing system uses. This system …

Might-E Wheel, Abigail Grills, Daniel Doke, Jared O'Rourke, Zach Jesberger

Interdisciplinary Design Senior Theses

Electric bikes are proving to be an increasingly reliable source of transportation, but with large price tags and existing conversion kits proving too complicated and unapproachable for the average user, commuters are failing to consider electric bicycles as an option. A prototype of a wireless, rear-wheel replacement to convert a bicycle from manual to full-power electric was built. This motorized wheel is called Might-E Wheel. Might-E Wheel was designed as the most approachable and user-friendly way to convert a bicycle from manual to full-power electric. Might-E Wheel was able to achieve a top speed of 27.5 km/h, a range of …

Akabot 2.0: Pet 3d Printing Filament From Waste Plastic, Jay Dubashi, Brian Grau, Alex Mckernan

Mechanical Engineering Senior Theses

Extrusion is how 3D printing filament is created. Melted plastic is pushed through an extrusion die and is shaped into a long thin strand of plastic. Extrusion machines are usually sized for industrial use, capable of creating hundreds of feet of filament a day. This filament is expensive to purchase, and many end-users would prefer to extrude their own filament, from a virgin plastic input or plastic waste input. There are no homescale filament extruders on the market for Polyethylene Terephthalate (PET) plastic waste. AkaBot was designed to allow end users to produce their own filament from a PET plastic …

Mobile Music: A Musical Therapy Assistance Device, Alex Hildebrand, Tanner Malkoff

Interdisciplinary Design Senior Theses

Children suffering from Cerebral Palsy often undergo gait therapy in order to strengthen and coordinate their trunks and legs. The patients often feel unmotivated to perform their gait training because the physical movements associated with it are difficult and there is no immediate reward. Physical therapists (PT) will often play music as an incentive to get the children focused on their physical therapy, but this is inefficient and impedes the PT from analyzing and tuning the patients' gait. Mobile Music is a small device designed for automating musical therapy during gait training. In this paper, we go through several design …

One-Ride Human Powered Vehicle, Alex Fisher, Alex Sahyoun, Geoffrey Schmelzer, Brendan Taylor, C.J. Toy

Mechanical Engineering Senior Theses

This document discusses the design, analysis, manufacturing and testing of the One-Ride human powered vehicle which was entered into the 2015 ASME West Coast HPVC Competition. The goal of the vehicle is to entice people to switch from gas powered vehicles to the One-Ride for trips of up to 20 miles round trip. The One-Ride design features fully adjustable seating and steering positions and was designed to fit anyone between the heights of 5'2" and 6'4" comfortably. The seat is adjusted using metal sliders, manufactured in the SCU machine shop, which fit into brackets attached to the frame. The bike …

Uavino, Matthew Belesiu, Aaron Chung, Kirby Linvill, Nathan Carlson, Phillip Coyle, Megan Peekema

Interdisciplinary Design Senior Theses

UAVino is a drone solution that uses aerial imagery to determine the overall plant health and water content of vineyards. In general, the system focuses on automating crop inspection by taking aerial imagery of a vineyard, conducting post-processing, and outputting an easily interpreted map of the vineyard's overall health. The project's key innovation is an auto-docking system that allows the drone to automatically return to its launch point and recharge in order to extend mission duration. Long term, UAVino is envisioned as a multi-year, interdisciplinary project involving both the Santa Clara University Robotics Systems Laboratory and local wineries in order …

Transcatheter Heart Valve Subassembly Device, Adam Aslam, Matthew Bezkrovny, Daniel Degree

Mechanical Engineering

No abstract provided.

Improved Tennis Racquet Stringer, William Ligon Bruno

Mechanical Engineering and Technology Senior Projects

What design change to a conventional ATS Sports model drop-weight stringer can be made to decrease the stringing time for a tennis racquet? To answer this, a detailed analysis on design, manufacturability, and structural integrity was done to design a product that is manufacturable within the timeframe and produces a device which decreases the stringing time. First, an analysis on each vital component was done including the ratcheting components, pressure arm/drop mass, etc. Second, a virtual model was created with auxiliary components to test different designs. Through this analysis and the virtual model it was indicated that a duel stringing …

Seat Jack, Justin Worden

Mechanical Engineering and Technology Senior Projects

Many people around the world struggle with mobility. One of the biggest obstacles for who may struggle in this area is the simple task of moving from a sitting position to their feet. For some, this is the only thing that keeps them from walking around. Creating a portable device to help move a person from their chair to their feet would extremely aid the efforts of completing this simple task at any given moment. This report provides a proposed solution for this simple reoccurring task that countless people painfully struggle with every day. In order to make this device …

A New Microfluidic Device For Complete, Continuous Separation Of Microparticles, Liang-Liang Fan, Xu-Kun He, Yu Han, Li Du, Liang Zhao, Jiang Zhe

Dr. Jiang Zhe

A microchannel with symmetric sharp corners is reported for particle separation, based on the inter-play between the inertial lift force and the centrifugal force induced by sharp corners. At an appropriate flow rate, the centrifugal force is larger than the inertial lift force on large particles, while the inertial lift force is dominant on small particles. Hence large particles are centrifuged to the center, while small par-ticles are focused at side streams, achieving complete particle separation. The device requires no sheath flow, avoiding the dilution of analyte sample and complex operation, and can be potentially used for many lab-on-a-chip applications.

Design Charts For Circular Fins Of Arbitrary Profile Subject To Radiation And Convection With Wall Resistances, G. Zhang, Benjamin T.F. Chung

Dr. Benjamin T.F. Chung

In this work, the optimization for a radiative-convective annular fin of arbitrary profile with base wall thermal resistances is considered. A fourth order Runge-Kutta method is used to solve the associated non-linear governing equa-tions. Further differentiations yield the optimum heat transfer and the optimum fin dimensions. To facilitate the thermal design, design charts for optimum dimensions are proposed. Furthermore, the fin effectiveness for the optimal annular ra-diative-convective fins is presented to check the practicality of the design. http://dx.doi.org/10.2174/1874396X01206010015

Novel Quantitative Macro Biomolecule Analysis Based On A Micro Coulter Counter, Y Han, H. Wu, F. Liu, Gang Cheng, Jiang Zhe

Dr. Jiang Zhe

We demonstrate quantitative biomolecule analysis using a micro coulter counter. Specific binding between antibody functionalized microparticles and target biomolecule cause large aggregates of microparticles. The micro coulter counter was employed to measure aggregation ratio, ratio of the aggregate counts to the total particle counts. Goat anti-rabbit IgG, used as a model biomarker, were tested in this paper. The experiment results showed that the aggregation ratio increases with the increasing biomolecule concentration, and the detectable concentration range from 16 to 160 ng/ml was achieved.

Static And Dynamic Responsive Behavior Of Polyelectrolyte Brushes Under External Electrical Field, Hui Ouyang, Zhenhai Xia, Jiang Zhe

Dr. Jiang Zhe

The static and dynamic behaviors of partially charged and end-grafted polyelectrolyte brushes in response to electric fields were investigated by means of molecular dynamics simulation. The results show that the polymer brushes can be partially or fully stretched by applying an external electric field. Moreover, the brushes can switch reversibly from collapsed to stretched states, fully responding to the AC electric stimuli, and the gating response frequency can reach a few hundred MHz. The effects of the grafting density, the charge fraction of the brushes and the strength of the electric field on the average height of the polymer brushes …

High School Bridge Program: A Multidisciplinary Stem Research Program, Jiang Zhe, Dennis Doverspike, Julie Zhao, Paul C. Lam, Craig C. Menzemer

Dr. Jiang Zhe

A Science, Technology, Engineering and Math (STEM) summer Bridge Program was developed for high school students. The program was designed to encourage students to consider choosing an engineering major in college and to explore STEM as a future career. This was accomplished through a 10-week program involving multidisciplinary research activities. The participants in the program included 33 high school students. Among former participants in position to make a choice in terms of attending college, 100% had chosen to continue on in college, and 86% had chosen to major in a STEM area. The results indicated that that the program had …

An Evaluation Of A Stem Program For Middle School Students On Learning Disability Related Ieps, Paul C. Lam, Dennis Doverspike, Julie Zhao, Jiang Zhe, Craig C. Menzemer

Dr. Jiang Zhe

A year long Science, Technology, Engineering and Math (STEM) program was developed for middle schools students on Individualized Education Programs (IEPs) involving learning disabilities. The workshops were designed to encourage students both on IEPs and not on IEPs to explore STEM as a future career choice by building their knowledge and confidence. The participants in the workshops included 11 students on IEPs and 15 students not on IEPs. Parents also provided feedback regarding their attitudes toward the program. The results indicated that there were increases in student participant knowledge and career interest for both the students not on IEPs and …

Passive Continuous Particle Focusing In A Microchannel With Symmetric Sharp Corner Structures, Liang-Liang Fan, Liang Zhao, Xu-Kun He, Hand Yu, Qing-Yu Wei, Jiang Zhe

Dr. Jiang Zhe

We report a continuous passive particle focusing method using a novel microchannel with symmetric sharp corners which induce curved streamlines and large centrifugal force on particles. At appropriate flow rate, the centrifugal force generated on particles exceeds the inertial lift force; particles driven by the centrifugal force migrate toward the center of the microchannel, achieving continuous particle focus-ing. With simple structure and operation, this method can be potentially used in particle focusing and ex-traction processes in a variety of lab-on-a chip applications.

A New Look At Optimum Design For Convecting-Radiating Annular Fins Of Trapezoidal Profile, Benjamin T.F. Chung

Dr. Benjamin T.F. Chung

This paper deals with a controversial problem in answering the question “Does the optimum fin design always exist? If not, what are the optimization ranges and limitations?” These authors employ a general example of convecting-radiating trapezoidal annular fin with heat transfer at the tip and wall resistance at the interface. The present results indicate that the answer to the above first question is negative. The ranges of fin optimum design under different thermal and physical conditions are proposed. The effects of Biot number, radiation number, the heat loss at the tip, fin profile and overall wall resistance on fin optimization …

Collapsible Bicycle Frame, Keith Stone

Mechanical Engineering and Technology Senior Projects

There are many situations where people could choose to ride a bicycle, whether it is to go to school, to a job, to meet with friends, or just for recreational purposes. However, once people reach their destination and have a break between their trips, they are left with a bicycle with little means of storing it while they go about their day. Some people buy a bike lock so that they can secure it in a safe location, while others may just lean it against a wall or even roll it into the building with them. However, according to FBI …

A Cell Model For Ductile Fracture With Applications, C. Fong Shih, Li Cheng, J. Faleskog, Xiaosheng Gao

Dr. Xiaosheng Gao

No abstract provided.

Analysis Of Ductile To Cleavage Transition In Part-Through Cracks Using The Cell Model Incorporating Statistics, Xiaosheng Gao, J. Faleskog, C. Fong Shih

Dr. Xiaosheng Gao

This paper describes an approach to study ductile/cleavage transition in ferritic steels using the methodology of a cell model for ductile tearing incorporating weakest link statistics. The model takes into account the constraint effects and puts no restriction on the extent of plastic deformation or amount of ductile tearing preceding cleavage failure. The parameters associated with the statistical model are calibrated using experimental cleavage fracture toughness data, and the effect of threshold stress on predicted cleavage fracture probability is investigated. The issue of two approaches to compute Weibull stress, the ‘history approach’ and the ‘current approach’, is also addressed. The …

A Mechanism-Based Approach For Predicting Ductile Fracture Of Metallic Alloys, Xiaosheng Gao

Dr. Xiaosheng Gao

Ductile fracture in metallic alloys often follows a multi-step failure process involving void nucleation, growth and coalescence. Because of the difference in orders of magnitude between the size of the finite element needed to resolve the microscopic details and the size of the engineering structures, homogenized material models, which exhibits strain softening, are often used to simulate the crack propagation process. Various forms of porous plasticity models have been developed for this purpose. Calibration of these models requires the predicted macroscopic stress-strain response and void growth behavior of the representative material volume to match the results obtained from detailed finite …

Enabling And Understanding Failure Of Engineering Structures Using The Technique Of Cohesive Elements, H. Jiang, Xiaosheng Gao, T. S. Srivatsan

Dr. Xiaosheng Gao

In this paper, we describe a cohesive zone model for the prediction of failure of engineering solids and/or structures. A damage evolution law is incorporated into a three-dimensional, exponential cohesive law to account for material degradation under the influence of cyclic loading. This cohesive zone model is implemented in the finite element software ABAQUS through a user defined subroutine. The irreversibility of the cohesive zone model is first verified and subsequently applied for studying cyclic crack growth in specimens experiencing different modes of fracture and/or failure. The crack growth behavior to include both crack initiation and crack propagation becomes a …

Numerical Modeling Of The Constraint Effects On Cleavage Fracture Toughness, Sunil Prakash, Xiaosheng Gao, T. S. Srivatsan

Dr. Xiaosheng Gao

Cleavage fracture has been an important subject for engineers primarily because of its catastrophic nature and consequences. Experimental studies of cleavage fracture did reveal a considerable amount of scatter and provided evidence of noticeable constraint effects. This did provide the motivation for the development of statistical-based and micromechanics-based methods in order to both study and analyze the problem. The Weibull stress model, which is based on the weakest link statistics, uses two parameters (m and σ u) to effectively describe the inherent distribution of the micro-scale cracks once plastic deformation has occurred and to concurrently define the relationship between the …