Imagine Magazine - Johns Hopkins - March/April 2014 - (Page 21)

small is BIG Studying Silicon Nanotechnology at UCSD by Gha Young Lee Near the end of my freshman summer, I was looking for Sailor. All of these things contributed to my growing underresearch opportunities when I discovered the Sailor Research standing of porous silicon-from how it's created to the vast Group at the University of California, San Diego. Headed by range of applications it can have. Dr. Michael Sailor, the group focuses on porous silicon (pSi) nanotechnology, which has wide applications in chemical and Porous Silicon: A Primer biochemical sensors, medical diagnostics, and drug delivery. Porous silicon is a manmade form of the chemical element According to his website, Dr. Sailor had already accepted a silicon that has nanoporous holes in its microstructure. The couple of high school interns in his lab. pores are created using an electrochemiDrawn to the relatively new technology cal etch, in which current is applied to and its promise of the opportunity to oxidize the silicon. The pore size can be grow with the field, I emailed my brief controlled by the density of the applied résumé to him, describing my interest current, and the sinusoidal waves of the in his research and my desire to intern current can create something called a in his lab. A few days later, I received a rugate structure, which has pores that Cross-section showing the pores of a reply: Dr. Sailor wanted to meet with me. rugate structure etched into a slicon wafer increase and decrease in diameter as a At the beginning of my sophomore function of depth in the porous layer. year, I met with Dr. Sailor. During our While porous silicon etched with meeting, we agreed that I would spend six to nine hours a more uniform pores appears dull brown, the oscillating porosweek in the lab, where I would shadow graduate students and ity of rugate structures produces bright colors in the visible light postdocs until I came up with a project idea. range. The rugate structure is a type of optical device known as I started by learning about safety precautions and training a photonic crystal. More familiar examples of photonic crystals on various pieces of equipment. For the first few months, I are peacock feathers and abalone shells. When viewed with a watched the grad students conduct their research, asked lots spectrophotometer-an instrument that measures the intenof questions, and read a book on porous silicon written by Dr. sity and wavelength of reflected light-the vibrant colors of a www.cty.jhu.edu/imagine imagine 21 http://www.cty.jhu.edu/imagine

Table of Contents for the Digital Edition of Imagine Magazine - Johns Hopkins - March/April 2014

In My Own Words
Chemistry Is…
Master of Reactions
Fascinated by Photochemistry
What About Labs?
Buckyballs and Nanocrystals
Small Is Big
Chemistry Among the Stars
Making Chemicals Safer, 21st Century Style
Selected Opportunities & Resources
Empowered to Change the World
The Buzz About History
Off the Shelf
Word Wise
Exploring Career Options
One Step Ahead
Planning Ahead for College
Students Review
Mark Your Calendar
Knossos Games

Imagine Magazine - Johns Hopkins - March/April 2014