Fig. 2.

Algorithm to calculate cell-driven deflections of patterned surfaces. A) Protein spots are microcontact printed onto a PDMS surface in a hexagonal pattern; cells attached to the surface cause microcontact printed spots to deflect. Spot centroid is identified via an image processing algorithm in Matlab (+). B) For each identified protein spot, the HexForce analysis package iteratively moves the protein location to the center of its 6 neighbors, until a converged solution is reached. This indicates the undeflected position of each spot. C) Delaunay triangulation of the measured deflected positions (blue) and the calculated undeflected positions (red). D) Deflected and undeflected nodes in C are used to calculate displacement vectors (green arrows). Cell outline is shown in white, and the region of influence for which the cell generates deflections is shown in green. Scale bar equals 10 μm.