Materials and methods of making have been developed for mass production of thermoplastic microfluidic chips. An elastomer diaphragm with a stress relieving feature can be used in microfluidic valves, pump diaphragms, and diaphragm micropumps. An optimized pump chamber design for complete fluid displacement and chamber geometry are provided. Microfluidic pressure regulators use a pneumatically actuated elastic membrane in a back-pressure regulator configuration. Microfluidic accumulators store pressurized fluid in a microfluidic chip. Removable caps for cell culture and a quick release top are described. Methods to incorporate hydrogels and ECM scaffolds have been developed. Electro pneumatic manifolds connect and control of multiple microfluidic devices vertically or on a rotary mechanism.