Paper Number
PO17 

Session
Poster Session

Title
MUnCH: A calculator for propagating statistical and other sources of error in passive microrheology

Presentation Date and Time
October 12, 2022 (Wednesday) 6:30

Track / Room
Poster Session / Riverwalk A

Authors (Click on name to view author profile)

1. Córdoba, Andrés (University of Chicago, Molecular Engineering)
2. Schieber, Jay D. (IIT, uCoSM)

Author and Affiliation Lines (in printed abstract book)
Andrés Córdoba¹ and Jay D. Schieber^2
1Molecular Engineering, University of Chicago, Chicago, IL; ²uCoSM, IIT, Chicago, IL 60616

Speaker / Presenter 
Córdoba, Andrés

Keywords
experimental methods; theoretical methods; computational methods

Text of Abstract
A complete propagation of error procedure for passive microrheology is illustrated using synthetic data from generalized Brownian dynamics. Moreover, measurement errors typical of bead tracking done with laser interferometry are employed. We use the blocking transformation method of Flyvbjerg and Petersen applicable to estimating statistical uncertainty in autocorrelations for any time series data, to account properly for the correlation in the bead position data. These contributions to uncertainty in correlations have previously been neglected when calculating the error in the mean-squared displacement of the probe bead (MSD). The uncertainty in the MSD can be underestimated by a factor of about 20 if the correlation in the bead position data is neglected. Using the generalized Stokes-Einstein relation, the uncertainty in the MSD is then propagated to the dynamic modulus. Uncertainties in the bead radius and the trap stiffness are also taken into account. A simple code called to aid in the calculations is provided in two versions. MUnCH as a Mathematica notebook or MUnCH as a Python script that performs the same calculations, but without the need for commercial software. The paper and the codes are available at Rheologica Acta 61, 49–57 (2022) and at https://github.com/andcorduri/GBD_MunCH.