Dresden 2020 – scientific programme
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BP: Fachverband Biologische Physik
BP 25: Cell Mechanics II
BP 25.5: Talk
Wednesday, March 18, 2020, 16:00–16:15, HÜL 386
Unbiased recovery of frequency-dependent mechanical properties from noisy time-dependent data — •Shada Abuhattum1, Paul Müller1, Vasily Zaburdaev2, Jochen Guck1, and Hui-Shun Kuan2 — 1Max Planck Institute for the Science of Light — 2Department of Biology, FAU-Universität Erlangen-Nürnberg
The mechanical response of materials to dynamic loading has great significance in various applications, ranging from performance and failure of engineered setups to exploring the structure of biological matter. This mechanical response is quantified using the frequency-dependent complex modulus. Probing materials directly in the frequency domain faces technical challenges such as a limited range of frequencies or lengthy measuring times. Therefore, it is common practice to extract frequency-dependent properties by fitting predefined mechanical models to measurements done in time-domain. Fitting these models circumvents problems with noise handling and signal shape imperfections. However, it precludes the probing of unique and unexplored material properties. Here, we demonstrate that the frequency-dependent complex modulus can be properly derived from stress-strain time-domain measurements even in the presence of random noise and systematic offset. We apply signal blurring methods to eliminate the systematic offset and to clean the complex modulus at lower frequencies. We then extend the range of reliable frequencies by employing a local averaging method to the complex modulus data. Finally, we propose an alternative probing procedure to increase the signal-to-noise ratio and further extend the frequency range for a reliable mechanical characterization.