Last summer, Lehigh University students, professors and postdoctoral researchers from across academic disciplines spent ten weeks examining inconsistencies of a technique that might one day assist medical professionals in evaluating patients’ levels of cancer risk.
Supervised by mechanical engineering and mechanics professors Hannah Dailey and Frank Zhang, the students collaborated on one of five supervised summer research projects through the Biosystems Dynamic Summer Institute (BDSI).
Created in 2006 with funding from the Howard Hughes Medical Institute, BDSI was the first program at Lehigh to provide cross-disciplinary team-based undergraduate research opportunities that emphasize relationships between biology and other disciplines like mathematics, physics, environmental science, chemistry and engineering.
Vassie Ware, co-director of the BDSI program along with Neal Simon, said students are strategically placed on research projects that fall outside of their subject areas to build cross-disciplinary approaches to the research problem at hand. Ware said the diversity of students’ backgrounds and expertise creates a conducive learning environment for both professors and students.
“People are often limited to thinking about diversity in terms of ethnic or gender diversity only, but when we’re talking about problem-solving in science and engineering, you need to integrate a lot of different ways of thinking,” she said. “It is often easy to follow your own training exclusively when attempting to solve complex problems; yet in the absence of integrating diverse points of view, the best solutions may never be uncovered.”
Ware added that the interdisciplinary nature of the BDSI program allows professors to approach projects from different perspectives and integrate students’ novel ideas into their research methods.
Dailey and Zhang experienced this integration first-hand in their labs. The professors led two teams of up to ten undergraduate and graduate students in a BDSI project during the 2016 and 2017 summer sessions.
The two summer teams consisted of students who had studied mechanical engineering, bioengineering, biochemistry, behavioral neuroscience, computer science, statistics and physics.
Dailey said the students’ expertise and individual curiosity helped determine the direction of the research and ultimately the outcome of their project, which investigated inconsistencies in atomic force microscopy, or AFM – an experimental technique commonly used to measure biological cells’ mechanical properties, such as stiffness.
The atomic force microscopy technique involves pressing a stiff indenter attached to the end of a micro-cantilever into the surface of a cell to make an indent. The indenter, which is either spherically or conically shaped, is pressed into the cell with a force of as low as ten piconewtons, or ten trillionth of a newton, where a newton is a force equal to the typical weight of an apple.
A laser system is then used to measure the depth of the indent and the applied force. Data-processing computer code translates these measurements into a value for the mechanical stiffness of the cell.
Under the direction of Dailey and Zhang, students grew biological cells on surfaces of different stiffnesses and used the atomic force microscopy technique to measure cells’ elasticity.
Dailey said the applications of this technique are particularly relevant today because cells’ mechanical properties are associated with different disease states. For instance, atomic force microscopy can be used to investigate the stiffness of cancerous cells and tissues, which tend to be very soft. The technique might one day be used to assess patients’ levels of metastatic risk, or the chance of cancer cells spreading to other areas of the body.
“That’s the downstream dream,” Dailey said. “And one of the reasons it hasn’t happened yet is that there are a lot of inconsistencies in the (atomic force microscopy) technique and in the way that different research groups do the data processing.”
Senior statistics major Katie Wu, who worked on the project in 2016, examined the inconsistencies in the atomic force microscopy technique using a statistical test with numbers she obtained from 60 publications.
She also ran statistical tests on the experimental results from the students’ atomic force microscopy lab tests. Wu’s tests supported the students’ hypothesis – that the shape of the indenter used to indent the cell changed the result of the experiment.
Dailey said that although Wu’s part of the project was not initially planned, her statistics background added an interesting new dimension to the work and helped refine the experiment.
“(BDSI got me interested) in research because it was exciting that we were finding new and different things no one had discovered,” Wu said.
Sophomore physics major Xay Rivera said the research she conducted in Dailey and Zhang’s lab helped her understand her passion for optical science, the branch of physics dealing with light. Rivera participates in the Rapidly Accelerated Research Experience science immersion program, or RARE program, which is also sponsored by the Howard Hughes Medical Institute.
During the 2017 summer session, Rivera photographed cells’ nuclei and cytoskeletal systems. She said the images she produced were later used to help the team understand their data and tell the visual story of the project.
“When I looked at those photos, (they) just looked like art to me,” she said. “Now I’m focused on optical science within the physics field.”
Ware said the BDSI program goes beyond the research itself. During the summer session, students participate in weekly workshops and seminars intended to help them develop their research, communication and professional skills.
Dailey said she sat down with her students each week to discuss and analyze their data. She also helped her team prepare a research presentation and a professional poster, which, she added, placed first in the annual BDSI poster competition, held in collaboration with the Baker Institute’s Launch Bay C program at the end of the summer session.
Zhang said the full-time nature of the program, which requires students to work 40 hours a week, allows professors and students to spot their improvements in the lab over the course of the summer.
“(Students) learn the (research) system and then you can see the students start to feel confident with it, and that’s a cool thing to go through,” Zhang said. “But if they really want to have a good research experience, they have to put the time in, and a full-time summer research experience is a great way to do that.”
Dailey and Zhang hope to write up the team’s results this fall for publication.
-Rebecca Wilkin '18 is a student writer with the P.C. Rossin College of Engineering and Applied Science and Managing Editor for The Brown and White.
October 30, 2017
- Department of Mechanical Engineering and Mechanics
- Biosystems Dynamic Summer Institute
- AFM Naniondentation Goes Deeper – Experimental and Computational Investigation of Substrate Stiffness Effects on Apparent Cell Elasticity (2017)
- Experimental and computational investigation of cell rheology including contributions of cell membrane and glycocalyx (2016)