We are creating implantable chips in order to implant engineered cells in human patients. These cells will act as factories to manufacture and deliver the right amount of drug when needed. Shown here is an advanced version of the chip carrying two kinds of cells in an intricate pattern. The cells shown in green produce the drugs while the red cells provide support for growth of the green cells. We design the cell patterning to ensure these two cell populations can communicate with each other for desired function within the device.