Improving Phonon Predictions in Organic Electronics

Organic electronics are built from semiconductors which contain Carbon atoms with alternating single and double bonds. These materials are either small molecules or polymer plastics. These materials can bend and stretch because the small molecules or polymer chains are only weakly bound to one another. This weak binding also affects how charges (electrons or holes) move in the material because the molecules or chains wiggle. As they wiggle, neighboring molecules will move closer and farther, changing the probability for the charge to move to the neighbor. As a result, it is necessary to have precise knowledge of just how the molecules wiggle to predict how well a material will conduct charge.

In general, these wiggles slow down charge transport, making devices based on organic semiconductors impractical. However, understanding how the molecules move can lead to design rules for improving these materials in the future. My job was to find new ways to predict the motions in these materials to try and find design rules.

Skills Utilized

Density Functional Theory
Molecular Dynamics
Density Functional Tight Binding
Machine Learning
Supercomputing
Python
Matlab
Linux

Microbubbles for Cancer Treatment though Ultrasonic Drug Delivery

Cancer treatment is one of the main challenges facing modern medicine. The most widely-used treatment currently is chemotherapy which relies on poisoning the patient as much as possible without killing them in hopes that the cancer will die first. This crude and barbaric treatment needs to be replaced with something highly precise and targeted. Microbubbles allow for targeted treatment of tumors.

Microbubbles are extremely small plastic bubbles which can contain a drug, air, or other material. Their shells can also be adapted to bind to tumors specifically. Then, the bubbles can be popped by using ultrasound to rapidly vibrate tiny pockets of air trapped inside. This means you can direct the bubbles and have the drug delivered only to the tumor. 

During a summer, I read over 100 scientific papers on microbubbles and summarized their results. The results along with our novel research were later compiled into a review paper.

Skills Utilized

R
Emulsification
Scanning Electron Microscopy
Coaxial Electrospray

High-Density Scintillating Glasses for Cancer Detection and Treatment

Proton therapy has been proposed as treatment for cancer for some time. It relies on the fact that protons deposit all of their energy at a very particular and tunable distance within a medium. This means that it should be possible to fire a shower of electrons directly into a tumor where they would deposit their energy and heat the tumor until it dies. 

For this setup to work, a compact, high-density detector is necessary. The kinds of materials that can detect protons and other high-energy particles are called scintillators. When a proton enters a scintillator and deposits its energy, the scintillator emits a small pulse of light relative to the energy deposited by the proton. Most commercial scintillators are made from plastic which means that it is nearly impossible to make them highly dense.

Glass, on the other hand, is transparent and can be made quite dense through addition of dense metals such as lead. During my undergraduate, I fabricated several high-density scintillating glasses. This was the first time scintillating glasses had been produced and I was able to produce scintillators which were nearly as dense as the single-crystal scintillators while costing ~1/1000 as much.

Skills Utilized

C++
Transmission/Absorption Spectroscopy
UV/Vis Spectroscopy
Gas Pycnometry