Graduate Student Profile: Xiaolong Luo
Laying the Groundwork for Future Innovation with Microfluidics

• Hometown:  Fujian Province, China
• B.S.: Mechanical and Electrical Engineering, Zhejiang University
• M.S.: Mechanical Engineering, Temple University
• Advisor: Professor Gary Rubloff
  (Materials Science and Engineering/Institute for Systems Research/Institute for Research in Electronics and Applied Physics )
• Started Program: Fall 2003

Fluids found in the human body must sometimes pass through spaces so small and in such tiny volumes that a drop of water would seem like a lake by comparison. Bioengineering graduate student Xiaolong Luo studies the behavior of these fluids as they move through devices not much larger that he designs and creates.

Luo's major area of study is microfuidics, the design and building of micro-scale devices and systems that use channels and chambers for the containment and flow of fluids  whose volume is measured in nanoliters (a nanoliter is approximately the volume of a fine grain of sugar).  Many of us use microfluidic devices without realizing it—they are what allow our inkjet printers to distribute tiny drops of ink to create photorealistic images.  Microfluidics also have a wide range of applications in biochemistry and medicine.  At such tiny scales, fluids' behavior changes, in part because their particles and any particles suspended in them are almost the same size as those of the system containing them, making the design and implementation of new devices especially challenging.  Luo's research group is trying to create metabolic reactions (biochemical processes) at this tiny scale, using "lab on a chip" technology that simulates particular conditions within a cell or the body and controls cell-signaling molecules.

Cell signaling occurs naturally in our bodies.  A cell signal is a "messenger molecule" manufactured by a cell and used to send a command from one cell type to another.  Recipients of these messages then perform any number of actions, including producing enzymes and changing state.  We know cells "talk" to each other in this way, but we don't know much about how it happens.  Luo's research seeks to understand what will impede or improve the passage of cell signals through the body.

Cell signaling technology could be used in drug discovery and improvement. If we understand how it works, what encourages and what impedes it, we could produce drugs that promote good signaling (such as making insulin) or restrict bad signaling (such as halting the growth of a tumor or correcting a biochemical imbalance). Luo is developing the technology and knowledge base that will make this kind of research possible. 

Left: One of Luo's chip designs. Right: A biodevice mold he produced utilizing the design, and others.

The chips Luo creates contain tiny channels, into which he puts enzymes that serve as catalysts. The reactions that occur on the chips simulate the creation of cell signal molecules in  living organisms.  Currently, he is designing devices to support cell signaling research in Professor Gary Rubloff's Nano-Bio Systems Laboratory.

In another project, Luo is studying cell response to nanoparticles, which are expected to be used in many applications, including nanomedicine, new materials, devices, and electronics.  Because of their small size, nanoscale particles can access to all parts of the body.  This makes them excellent candidates for new types of medicine.  It is important to understand not only how they can benefit medical practice, but also whether they might endanger human health and the environment through their broad manufacturing and use. 

To accomplish this, Luo creates micro-culture devices in which cells are exposed to different types of nanoparticles, and their response is observed.  This approach has the potential to be faster and more accurate than traditional cell culture and staining.  Unlike older techniques, it allows researchers to monitor cell activity and health in real time, for example by connecting the device to a mass spectrometer, which monitors variations in cell emissions inside the minute environment. 

Like many of our bioengineering graduate students, Luo comes from a different engineering discipline; in his case, mechanical engineering.  He was exposed to bioengineering while working on his master's degree at Temple University.  There he was inspired by one of his committee members, who was both a medical doctor and an engineer. Luo noticed that biologists, doctors, and engineers all had their own ways of thinking and expressing scientific issues, and felt that the field of  bioengineering would build bridges between them.  "The most important thing, at least for me," he says, "is that bioengineering is an interdisciplinary education opportunity."

A microfluidics system.

The variety of faculty members with whom he works closely confirms his observations: his advisor, Professor Gary Rubloff, is a member of the Department of Materials Science and Engineering, holds joint appointments with the Institute for Systems Research (ISR)  and the Institute for Research in Electronics and Applied Physics (IREAP), and is the Director of the Maryland NanoCenter.  Luo also works on a project with Professors William Bentley (Chair, Fischell Department of Bioengineering), Reza Ghodssi (Electrical and Computer Engineering), and Greg Payne (Director, UMBI Center for Biosystems Research).

Luo was attracted to the University of Maryland by its location, and the variety and support the Greaduate Program in Bioengineering offers.  "The school is beautiful and the people are interesting," he says.  "I like the area and the presence of biotech companies [nearby].  My family likes it here too—it's close to [Washington,] D.C., there are free museums, and lots of places to go.  The faculty and staff [are] very responsive to students, particularly in their first year....Students are allowed to choose advisors after talking to many professors, so they can see what they find interesting...[what] they're really interested in working on, and are motivated by."

Luo is optimistic about what the future holds, and hopes that his research will serve as the foundation for future innovations in products and devices designed to help people.  "I can see bioengineering's a growing field," he says. "I feel it will change our lives in a way electrical and computer engineering has in the past few years.  Last decade was the 'IT decade.'  I think this one is going to be the 'bioengineering decade.'"