It is well known that some cell types have a naturally elongated shape and spontaneously align with their neighbors like nematic liquid crystals. The alignment of cells determines not only their migration patterns and the cell-cell communication, but also the mechanics of the tissues. There is increasing evidence that topological defects in cell alignment affect cell dynamics, cell organization and even morphogenesis. 
We induce topological defects and distortions in monolayers of 3T3 fibroblasts using micro-patterned ridges with varying height and spacing. This simple tool constitutes a useful platform to characterize various properties of the cell monolayers. For example, we characterize the cell organization and dynamics varying the cell-substrate adhesion and we show a distinct collective motion for strong or weak adhesion. If the adhesion between the cells and the substrate is sufficiently weak, the cells grown at high density spontaneously detach to form a thin free-floating layer. We verify that as cells detach, the nematic order parameter decreases and the cells contract more along the nematic director. We use this concept to program Gaussian curvature in the detached fibroblast layers, thus demonstrating the possibility to control the final shape of the cell layers through 2-D alignment.