Figure 1. Measurement of cell traction forces with hydrogel traction force microscopy (TFM) and arrays of elastomeric microposts.

Cell contractile machinery produces traction forces (shown as red vectors), which are transmitted to the extracellular environment via focal adhesions, which transmit forces to the nucleus via cytoskeletal (figure inset) to enable mechanotransduction. Hydrogel platforms offer continuous substrates for cell adhesion whereas microposts provide discrete binding “islands.” In both systems, cell tractions are calculated from substrate displacements. 3D tractions can be computed on hydrogels if x-, y-, and z-axis deflections of fiducial markers are visualized by confocal microscopy. Figure adapted with permissions from [14, 19, 199]