Metastatic cancer cells respond to chemical and mechanical stimuli in their microenvironment that guide invasion into the surrounding tissue and eventually the circulatory/lymph systems. The NANIVID is designed to be an in vivo device used to collect metastatic cancer cells by providing a gradient of epidermal growth factor through the controlled release from a customized hydrogel. The model cells, MTLn3 and MenaInv, both derived from a rat mammary adenocarcinoma, will migrate toward the device and be collected in the chamber. A set of electrodes inside the chamber will provide real-time data on the density of cells collected in the device. The characterization and optimization of the electrodes in vitro will be reported, as will the development of an equivalent circuit model used to describe electrode behavior. The ultimate goal of this work is for the NANIVID to be used for in vivo investigations of a rat model of mammary cancer. Furthermore, since the morphology, mechanical properties, and movement of cells are influenced by the microenvironment, a combined scanning confocal laser microscope and atomic force microscope will be used to study these relationships. This work will further the understanding of the dynamics and mechanics of metastatic cancer cells as they leave the primary tumor and metastasize.