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Fralin fellow helps jumpstart research in new Virginia Tech engineering lab

April 18, 2017

Ahmed Elnahhas in lab
Ahmed Elnahhas, of Kuwait City, Kuwait, a junior majoring in mechanical engineering, is one of 14 recipients of the Fralin Undergraduate Research Fellowship.

Soon after coming to Virginia Tech, Ahmed Elnahhas wanted to get his feet wet in research, but he couldn’t find an opportunity.

Then, at the end of his sophomore year, he got an email from Shima Shahab, an assistant professor of biomedical engineering and mechanics in the College of Engineering. That semester, Elnahhas was taking her class, Mechanics of Deformable Bodies, and she thought he would be a good fit for her up-and-coming lab.

“She offered me the chance to come and learn about her projects, so at the time the goal was for me to get a variety of experiences in vibrational analysis, which is her specialty,” said Elnahhas, of Kuwait City, Kuwait, a junior majoring in mechanical engineering in the College of Engineering at Virginia Tech.

Elnahhas is one of 14 recipients of the Fralin Undergraduate Research Fellowship, a new program created by Dennis Dean, director of the Fralin Life Science Institute and the university’s Stroobants Professor of Biotechnology, in partnership with the Office of Undergraduate Research.

The goal of the program is to increase diversity in undergraduate research. Each Fellow receives $1,000 to conduct research with a Virginia Tech faculty mentor over the course of one academic year.

At 6 p.m. on Thursday, the fellows will present their research at the 2017 Fralin Undergraduate Research Fellowship Showcase in Fralin Hall. The event will involve a reception, poster session, and brief remarks by Dean and Thanassis Rikakis, executive vice president and provost at Virginia Tech. The public is welcome. Fralin Hall is located at 360 West Campus Drive in Blacksburg.

When Shahab contacted Elnahhas, she was just beginning her position as a new faculty member and did not yet have a lab space, so she let Elnahhas choose his first project.

He chose to model surface acoustic (sound) waves, which are similar to ocean waves but much smaller in size. During the summer of 2016, he developed mathematical equations to model how these move and behave across a surface within a certain kind of material.

“The idea was to direct the waves into a specific location on the surface of the medium, allowing us to control the fluid on top,” Elnahhas said.

At the same time, Shahab wanted Elnahhas to get acquainted with experiments, so she set him up with Muhammad Hajj, the J. Byron Maupin Professor of Engineering and associate dean of the Graduate School. Hajj directs the Center for Energy Harvesting Materials and Systems and the Nonlinear Dynamical Systems Laboratory in Norris Hall. There Elnahhas gained experience running tests on oscillating airfoils.

Then, at the end of the summer, Shahab moved into the new Multiphysics Intelligent and Dynamical Systems Laboratory (MInDS) at Virginia Tech, which is supported by the Department of Biomedical Engineering and Mechanics in the College of Engineering and by a diversity and inclusion seed grant from the Institute for Critical Technology and Applied Science.

Elnahhas began putting his mathematical models into observable, experimental practice while helping Shahab.

“This was very valuable experience because I got to help set up the lab from scratch,” Elnahhas said. “And receiving a fellowship specifically tailored for this research gave me more motivation to put a lot of effort into my work.”

Elnahhas also started applying the theoretical models for acoustic energy that Shahab had developed during her Ph.D. She gave him mathematical equations that he used to derive values, which in turn gave him an idea of how energy was transferred from a transducer to a receiver. The ultimate goal was to develop a means to charge sensors wirelessly, such as charging a heart pacemaker from outside the body.

“Batteries in pacemakers have to be replaced every five to seven years,” explained Shahab, “but acoustic energy transfer may make it possible to charge these wirelessly and safely through the body.”

Elnahhas is now working on another project with biomedical applications by applying mathematical models made by Marjan Bakhtiari-Nejad, of Tehran, Iran, a doctoral student in biomedical engineering and mechanics in Shahab’s lab, who studies acoustic energy transfer and bubble dynamics.

“We’re trying to quantify the behavior of bubbles close to different surfaces based on the mechanical properties of those surfaces,” said Elnahhas. “The process can then be reversed, and the observable behavior of bubbles could be used as sensors. An example would be the behavior of bubbles close to biological tissue.”

In time, acoustic waves and bubbles could distinguish healthy cells from cancerous ones since they have different properties and behave differently physically.

“Elnahhas performed excellent research and made significant progress in developing experimental platforms for acoustic energy transfer systems,” Shahab said. “The outcome of his research are three conference presentations, and he will present these results at the 31st Annual National Conference on Undergraduate Research at the University of Memphis in April.”

Elnahhas has recently been awarded an ACC Creativity and Innovation Grant for $2,000 that will support his student-led project in the MInDS lab this summer.

“Everything is based on the same fundamentals. A system vibrates with a certain frequency, you give it an input, and you can observe a response,” Elnahhas said. “But this can be applied in many different ways, as I can give you an equation for two different systems but they will look identical and have the same behavior. As one of my professors said, one set of equations could represent electromagnetic waves, cells vibrating, or a bird landing on a tree. It’s all the same thing, which is amazing. The beauty of the universe is that it can be explained in mathematical laws. Once we know the fundamentals, we can apply them however we want.”

Written by Cassandra Hockman

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