Cellular traction forces are crucial in cell functions like migration, communication, mechanotransduction, adhesion, and shape regulation. Traction force microscopy uses the displacements of fluorescent beads embedded on the surface of a soft substrate of known mechanical properties to quantify the forces induced by cell contraction. However, current methods based on image correlation are time-consuming and suffer from poor repeatability. Here, we propose to use the Demons algorithm as a faster and more accurate approach to measure the displacement of beads. We demonstrate using simulations of mechanically constrained gels confirm that this approach outperforms the gold standard, as it is ten times faster, more robust to noise and defocusing, and capable of producing physiologically relevant displacement fields. Live cell traction force experiments validate the reproducibility of the technique.
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