We discuss the design, fabrication and testing of a hybrid microsystem for stand-alone cell culture and incubation. The micro-incubator is engineered through the integration of a silicon CMOS die for the heater and temperature sensor, with multilayer silicone FDMS (polydimethylsiloxane) structures namely, fluidic channels and a 4mm diameter, 30μL, culture well. A 25 micron thick PDMS membrane covers the top of the culture well, acting as barrier to contaminants while allowing the cells to exchange gases with the ambient environment. The packaging for the microsystem includes a flexible polyimide electronic ribbon cable and four fluidic ports that provide external interfaces to electrical energy, closed loop sensing and electronic control as well as solid and liquid supplies. The complete structure has a size of (2.5×2.5×0.6cm3). We have employed the device to successfully culture BHK-21 cells autonomously over a sixty hour period in ambient environment.