Cardiac muscle cells are known to respond to both biochemical and mechanical stimuli. Dr. Russell's lab team of Motlagh, Boateng, and myself is conducting research to develop a more effective way to culture cardiac cells in vitro so they more closely mimic in vivo activity. The objective is to grow cardiac myocytes on various pegged or grooved membranes. As a research assistant, I have assisted in comparisons of the morphology and alignment of cardiac cell cultures on flat membranes as compared to pegged or grooved membranes. The membranes are silicone molded from a microfabricated template containing pegs and grooves of micron scale. We stretched the membranes up to 50% strain and measured the deformation of the pegs. Phase microscopy analysis found unacceptable distortion at 50% strain but acceptable changes in the physiological ranges. After rat heart cells were plated on these membranes, their alignment and morphology on each of the 3 types of membranes was analyzed from phase micrographs. It was found that the cells grown on grooved membranes were better aligned than on flat membranes, but that the morphology of the myocyte attachment site was more life-like on pegged membranes. We conclude that the pegged and grooved membranes allow one to culture cells that more closely mimic the alignment, attachment, and morphology of cells in the heart. Also, this system will allow more insight into the effects of various synchronized mechanical stresses on the heart as a whole.