Integrated PDMS/CMOS microsystem for autonomous incubation and imaging in cell culture studies

We discuss the design, fabrication and testing of a hybrid microsystem for stand-alone cell culture, incubation and imaging. The micro-incubator is engineered through the integration of two CMOS dies. The first for the heater and temperature sensor, and a second die for imaging. A multilayer PDMS (polydimethylsiloxane) structures is used to create not only the fluidic structures but to encapsulate the CMOS dies. The microfluidic features include fluidic channels, a 4mm diameter, 30μL, culture well and a 25 micron thick PDMS membrane that covers the top of the culture well, acting as barrier to contaminants while allowing the cells to exchange gases with the ambient environment. The micro-incubator interface includes with a flexible polyimide ribbon cable and four fluidic ports. 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.