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  • AME Special Seminar

    Thu, Feb 17, 2022 @ 03:30 PM - 04:30 PM

    Aerospace and Mechanical Engineering

    Conferences, Lectures, & Seminars

    Speaker: Neda Maghsoodi, California Institute of Technology

    Talk Title: Nonlinear Dynamics of Soft Filaments: From Biology to Engineering

    Abstract: Filaments of soft materials such as rubber and biopolymers can easily undergo large complex deformations under external stimuli. Soft filaments offer exciting applications in engineering, life science, and medicine since their nonlinear conformational changes can be harnessed for robust functional mechanisms. Understanding the dynamics of soft filaments is fundamental to advancing future engineering and medical applications. In this talk, I present analytical models for two fascinating soft filaments that function in the nonlinear regime; 1) protein filaments forming the contractile injection machinery of the virus bacteriophage T4, and 2) photoactivated liquid crystal elastomeric (LCEs) filaments proposed for future soft robotics. I present dynamic models for both filaments based on continuum rod theory to predict their dynamical nonlinear behaviors. For context, bacteriophage T4 is an intriguing nano-scale injection machine that infects the bacterium E. coli (its host) by rupturing the cell membrane and then injecting its genome into the host cell. The injection process is initiated when the injection machine, composed of protein filaments, undergoes a nonlinear conformational change to drive the T4 needle into the host. Photomechanical LCEs are engineered, light-sensitive polymers that undergo large reversible deformations under illumination. For these systems, I show how phage T4 exploits large deformations of the protein filaments for efficient DNA injection, and how one can harness nonlinear deformations of LCE filament to generate periodic motions under steady illumination. These findings have significant implications for designing future biomedical devices and bio-inspired soft robotics.

    Biography: Neda Maghsoodi is a postdoctoral scholar at the California Institute of Technology (CalTech). Neda received her Ph.D. in Mechanical Engineering in 2019 and her M.Sc. in Biomedical Engineering in 2017 from the University of Michigan-Ann Arbor. Prior to joining the University of Michigan, she earned her B.Sc. and M.Sc. both in Mechanical Engineering from Iran. Her research lies at the interface of applied mechanics, materials science, and biology and develops novel theoretical models to elucidate nonlinear dynamics of soft filaments at a broad range of time- and length-scales. In her academic career, Neda was named a Rising Star in Mechanical Engineering by UC-Berkeley (2020), received the Best Paper award in the ASME International Conference on Micro- and Nanosystems, and received the Best B.Sc. Thesis award of the year from the Iranian Society of Acoustics and Vibration. The novelty and significance of her Ph.D. research have been featured in Biophysical Journal as the New and Notable Article and in several news outlets.

    Host: AME Department

    More Info: https://usc.zoom.us/j/95277955610

    Webcast: https://usc.zoom.us/j/95277955610

    WebCast Link: https://usc.zoom.us/j/95277955610

    Audiences: Everyone Is Invited

    Contact: Tessa Yao

    Event Link: https://usc.zoom.us/j/95277955610


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