Traction Force Microscopy (TFM)
Using polyacrylamide gels with fluorescent microspheres, students in Professor Saif’s laboratory Samantha and Sandeep show how to track cellular motion and calculate traction forces. In this video, the students first walk through the procedure of creating the polyacrylamide gels with the microspheres. Later in the video, the students show the calculation of displacement and traction forces.
Experimental Methods for Biological Machines
BIOE 498 || ME 498
4 credit hours Live videoconferenced lectures UIUC campus on Mondays and Wednesdays, 3:30-5:00 PM CST Taught by Illinois Professors Rashid Bashir, Minh N. Do, Martha Gillette, Hyun Joon Kong, K. Jimmy Hsia, Gabriel Popescu, Taher Saif, Paul Selvin, Fei Wang, Ning Wang, Yingxiao Wang This course introduces students to the students unique experimental methods that are important to successful research in developing biological machines. These methods are in general not covered in standard experimental courses at most universities, and often not included in text books. The EBICS Graduate Teaching Consortium provides an opportunity for students to be exposed to a broader selection of experimental methods, and develop potential inter-institution collaborations. The EBICS (Emergent Behavior of Integrated Cellular Systems) mission is to “Create a new scientific discipline for building living, multi-cellular machines that solve real world problems in health, security, and the environment.” This mission is achieved through integrated research and education efforts, human resource development, diversity and outreach programs, and knowledge transfer activities. EBICS is an STC, Science and Technology Center (STC). The Itegrative Partnerships program supports innovative, potentially transformative, complex research and education projects that require large-scale, long-term awards. STCs conduct world-class research through partnerships among academic institutions, national laboratories, industrial organizations, and/or other public/private entities, and via international collaborations, as appropriate. They provide a means to undertake important investigations at the interfaces of disciplines and/or fresh approaches within disciplines. STC investments support the NSF vision of advancing discovery, innovation and education beyond the frontiers of current knowledge, and empowering future generations in science and engineering.
Professor Saif's research focuses on the mechanics of microelectromechanical systems (MEMS), fracture mechanics, submicron materials behavior and bio-MEMS. He uses MEMS devices, often of his own design, to explore the mechanics of extremely small things-from nanocrystalline metal films to living cells.
Using micro force and strain sensors, he demonstrated for the first time that plastic deformation in nanocrystalline metal films can be reversible. After deformation, metals with grain sizes between 50 and 100 nanometers recovered 50 to 100 percent under macroscopically stress-free conditions. This recovery was time dependent and thermally activated, and involved a distribution of activation energies. When stretched again, the metals showed no effects from the previous strain. The research, which was reported in Science, raises the possibility of designing and manufacturing metal components that recover or heal themselves after being deformed or dented.
Professor Saif also developed an innovative MEMS device that places loads on single living cells by stretching them, and he records their responses through the use of MEMS force sensors that he also developed. His research has advanced the state of knowledge about cells because he found that contrary to conventional wisdom, the force response of a cell has a linear relationship to the amount of force applied rather than being much higher. He also found that the force response is reversible, that is, the cell's force response follows the loading path as the stretching is decreased. Again, this defied expectations that cells would not return to their original configurations once a load was removed. In measuring a cell's response to stretching, he was also able to determine how strongly a cell was attached to tissue. He believes knowledge of such mechanical properties as cell stickiness and stiffness may have important implications for the detection and treatment of such diseases as cancer, atherosclerosis and malaria. Also in the area of biomechanics, he and Professor Akira Chiba in the Department of Cell and Structural Biology discovered that mechanical tension in neuronal axons plays an essential role in neurotransmission, a key component of memory and learning.
His work with self-assembled nanowires has been similarly groundbreaking. He and a colleague combined two different methods for making nanowires-each having its own drawbacks-to create a new and effective method that creates wires 40 to 50 nanometers in diameter. Reducing the size of nanowires is critical to making electronic devices smaller and more powerful.
Narrator 1: Samantha Knoll, Graduate Student, Mechanical Science and Engineering
Narrator 2: Sandeep Anand, Graduate Student, Mechanical Science and Engineering
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