Senior Design Projects Spring 2014
Nanofiber Manufacturing Device for Stem Cell Studies
Advisors – Dr. Nitin Agrawal, Dr. Jennifer G. Barrett
Team – Alaa Alhussein, Alex Baker, Anuraag Ravikumar, Katrina Nguyen
Website – http://bioeng-proj.vse.gmu.edu/492-f13-team1/
Our device consists of an electrospinning apparatus including a rotating, surface-patterned mandrel and mobile spinneret. The mandrel is connected to the grounded lead of a high voltage DC power supply, and its rotation driven by a DC motor. A microcontroller controlled the rotation speed of the motor and the x-y movement of the syringe. The syringe expelled a polymeric solution (consisting of PLGA and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)) onto the mandrel. The positive lead of the DC power supply charged the polymeric solution through its connection to a conductive needle tip causing a jet of fibers to eject from the syringe and onto the mandrel to produce 8”x6” sheets of nanofibers.
The concentration of PLGA, the flow rate of the polymeric solution, and the rotation speed of the mandrel dictated the ideal parameters for making successful scaffolds. After examining our samples under scanning electron microscopy (SEM) and liquid intrusion tests the scaffolds showed adequate nanofibers’ alignment, scaffold porosity, nanofibers’ diameter (200-600nm). Our results confirmed that our device was able to create nanofiber scaffolds with necessary properties to successfully seed and differentiate stem cells.
Lab-in-a-Box: Portable Incubator and Image Processing Program for Conducting Bacterial Growth Experiments
Advisor – Dr. Caitlin Laurence
Team – Emily Eastlake, Katie McDonald
Website – http://bioeng-proj.vse.gmu.edu/492-f13-team2/
During one COMPLETE center workshop, teachers culture bacteria in a lab incubator, measure the growth of the colony’s area versus time, and perform statistics and regression on the resulting data points. Unfortunately, teachers cannot bring this lesson back to their classrooms because they have no realistic mechanism for culturing bacteria in a high school setting. Additionally, the current method of measuring bacterial colony area, which involves tracing the edge of the colony onto a transparency, is inefficient and can be inaccurate.
Our research project consisted of building a simple, low-cost, easy-to-use incubator out of readily available materials that can be used to culture bacteria in a high school setting. In addition, we wrote an image processing algorithm to calculate the area of bacterial colony growth (in mm2) from a smartphone image of the petri dish. Initial results suggest our box will provide teachers with an inexpensive means for culturing bacteria in a high-school setting. In addition, our image-processing program should improve upon the existing tracing method for measuring colony area, potentially eliminating the need to manually measure the area of bacterial colonies.
Contactless Pulse Transit Time Measurement and its Potential Application in Measuring Blood Pressure
Advisor – Dr. Vasiliki Ikonomidou
Team – Martin Cissel, Misha Vaidya, Nhien Tran
Website – http://bioeng-proj.vse.gmu.edu/492-f13-team3/
UNAR: User Navigated Autonomous Robot
Advisors – Samantha Watkins, Anthony Nunez
Team – Liban Hassan, Ahsanul Haque, and Shezeen Rehmani
Website – http://bioeng-proj.vse.gmu.edu/492-f13-team4/
Our task for this project was to design an assistive device that target customers with disabilities limiting them from carrying excessive weights. The proposed solution we implemented was an autonomous robot on wheels with indoor and outdoor capabilities, able to follow a user, avoid obstacles, and carry the user’s belongings. Our design was equipped with a Polulu IR beacon trans-receiver, with a matching homing transmitter carried by the user. The robot also has ultrasonic sensors attached to the front of the chassis for obstacle avoidance. The robot will also feature a compartment for the user to place their belongings.
We have tested obstacle avoidance along with the beacon transceiver using subsumption logic flow for information processing by the ATmega2560 microcontroller. The entire system is fully autonomous and self-contained. Our design was successful in carrying a specific load for the user, while avoiding obstacles and maintaining reasonable proximity.
Self-Guided Pedicle Screw System
Advisors – Dr. Mahesh B. Shenai, Dr. Siddhartha Sikdar
Team – Von Botteicher, German Borda, Susheela Meyyappan
Website – http://bioeng-proj.vse.gmu.edu/492-f13-team5/