Drexel University: Materials Science and Engineering

I recently had the opportunity to attend a weeklong class on materials science at Drexel University. Initially, I thought materials science involved visible changes to materials and mixing substances together. However, I learned that much of materials science occurs at the atomic level.

The camp included various lectures that provided a solid foundation in materials science. Some of the key topics covered were:

·      Properties of Materials

o   Mechanical properties

-strength, ductility, hardness, resistance, and toughness

o   Electrical properties

-resistance and resistivity

·      Types of Materials

o   Metals

o   Polymers

o   Ceramics

o   Polymers

One of the highlights of the camp was the hands-on lab work, particularly an experiment called electrospinning, where we created nanofibers. Here's a brief overview of the process:

image: https://www.nanoscience.com/techniques/electrospinning/

·      Electrospinning Apparatus: We used a special apparatus that included a syringe to pump out a monomer solution slowly while an electrical current flowed through the solution. A device that sends tens of thousands of volts through the system has one end (positive or negative) attached to the metal opening of the syringe and the other end attached to the collector (a metallic object)

·      Process: As the solution traveled from the syringe to a piece of aluminum foil covering the collector, the solvent (water) evaporated, leaving behind polymers that formed long chains, creating a web of nanofibers.

·      Experiment Trials: We conducted three trials to observe how changing the voltage affected the diameter of the nanofibers. Our hypothesis was that higher voltage would result in thinner nanofibers due to the increased pulling force of the electrical current.

·      Measurement: Using a scanning electron microscope (SEM) at 10,000x zoom, we captured images of the nanofibers and measured their diameter using image processing software (ImageJ). We found that as the voltage increased, the diameter of the nanofibers decreased, supporting our hypothesis.

In addition to electrospinning, we engaged in other lab activities:

·      Mechanical Property Testing: We tested the tensile strength of four items, including an injection-molded dog bone shape and three 3D-printed dog bone shapes, each printed in different directions (vertically, horizontally, and diagonally). We used a machine to pull the objects apart until they broke, allowing us to determine the Young's modulus and tensile strength. The diagonally printed object proved to be the strongest.

image: https://www.matweb.com/reference/tensilestrength.aspx

·      Electrical Properties: We tested the resistance of wires, learned about fiber optic cables, as well as resistors and how to read them. We also explored solar cells, their energy production limits, and the quadratic relationship between light intensity and power output when using a UV flashlight to power a solar panel.

Overall, the materials science camp at Drexel University was a fascinating and educational experience. I gained a deeper understanding of the field, particularly the intricate processes occurring at the atomic level. Materials science is truly an intriguing field, and I am grateful for the opportunity to have participated in this class.