Ben Bluth's Internship Experience
During the summer of 2006 I traveled to Seville, Spain to conduct microfluidics research in the laboratory of Dr. Alfonso Gañán-Calvo. Over the course of the ten week program I studied minimum flow rates in a process called Flow Focusing.
Developed by Dr. Gañán-Calvo in 1996, Flow Focusing is a process which produces monodisperse liquid particles on the micron scale. This is accomplished by pushing liquid though a capillary which is positioned above a circular orifice. By introducing a flow of gas and therefore a pressure drop across the orifice, the liquid takes on a conical shape which rapidly breaks down into a fine, particulate spray. This process is highly variable as flow rate, gas pressure, distance from orifice, type of liquid, and capillary and orifice diameters can all be altered. However, only under certain conditions of the aforementioned variables will Flow Focusing occur. This can be 
determined by observing the stability of both the meniscus and the jet produced. An unstable meniscus has blurred edges and will often flicker, while a stable meniscus has sharp edges and a clear, glass-like appearance that does not waver. For menisci that are too small to view, it is necessary to observe the jet that exits from the orifice. In this instance, unstable jet flow appears very faint to the naked eye and contains thin streaks of liquid along with large scattered spray. This is contrasted by stable jet flow which has bright illumination as a result of a finer, concentrated stream with uniform characteristics. Both the jet test and meniscus test have clear transitions between the two states and as a result it is easy to characterize the flow while making small alterations in the input variables.
Using this knowledge, I explored the minimum flow rates necessary to achieve Flow Focusing over a range of conditions. I took data sets of varying pressures, distances from the orifice, and concentrations of water and ethanol. Collecting this wide array of data formed a clear picture of the minimum flow rates for Flow Focusing and provided an accurate, multidimensional map of the effect of pressure, distance, and liquid composition on stability.
Working in a foreign laboratory provided a wealth of knowledge and experience. It was an amazing opportunity to explore a new field of physics and interact in a research setting outside of Emory. Although the adjustment period was short, I found that some of the laboratory practices were different from those I was accustomed to in the United States. While it was by no means daunting, language and general lab procedures were both minor issues that arose while conducting research. In high school I had taken four years of Spanish, but being absent from the language for three years I was by no means fluent when I touched down in Spain. Although English often suited me just fine in the laboratory, there were researchers that either spoke no English or were not comfortable using it. I found it helpful to communicate with English speakers in Spanish and have them help me with words that I did not know. This was particularly helpful with specific vocabulary on technical or scientific terms. Having knowledge of the names of common tools and instruments made it much easier to communicate with those that could not understand English and ensured that I could always get what I needed to continue my experiments.
In addition to the occasional language barrier, lab practices were somewhat different than what I had experienced at Emory. This was specifically the case with safety, as the rules governing chemical and machine use were much more lax than in the United States. The easiest way to ensure your own safety is to always understand your task and make your lab head aware if you are not comfortable completing it. On my first day of research I was told I could use the heavy machinery whenever I needed it for my project. As I was not qualified to do such work, whenever I needed something cut or altered I would employ one of the others in the laboratory to help me.
Despite the fact that research is the main purpose of the IRES grant, the majority of your time is spent outside of the laboratory. There are plenty of opportunities to explore the culture of your city and travel around the globe as you broaden not only your scientific knowledge but also your depth as a person. While in Seville I lived with five roommates from all over Europe and would constantly meet people from around the globe. I visited a dozen cities around Spain and took in amazing sites from beaches to museums.
The opportunities were endless and after ten full weeks of research and travel I could have easily filled ten more. IRES is definitely a once in a lifetime opportunity to broaden your horizons in every realm of being. I will never forget my experience in Spain and will always cherish the memories from that summer abroad.