Microfabrication approaches such as printing with micro and nanoscale resolution have dramatically changed our society through their use in diverse fields. These engineering tools are also useful for many biological applications ranging from drug delivery to DNA sequencing since they can be used to fabricate small features at a low cost and in a reproducible manner. In addition, the ability to print materials at the micro and nanoscale is potentially important for many biological and biomedical applications. Our goal is to use these techniques to better understand and manipulate cell behavior (e.g. stem cells) and to fabricate devices for high-throughput screening. This talk will describe new materials and methods developed in our lab to regulate and analyze the interaction of cells with their surroundings. To control cell migration and to restrict cell or colony size, cells and proteins were patterned using numerous printing and molding methods based on deposition of polymers. To control cell-cell contact, we have developed methods based on layer-by-layer deposition of ionic biopolymers to generate patterned co-cultures. In addition, we have developed microfluidic-based approaches to synthesize novel materials and to interface cells inside microdevices.