Improved micro-flow regulator for drug delivery systems

The paper reports on the design, manufacturing, and experimental testing of a micromachined pressure compensating flow regulator. This device was designed to provide a constant liquid flow rate of 1 ml/hr within a pressure difference of 100 to 600 mbar. At pressures higher than 600 mbar the device is designed to block the flow, preventing an over-delivery of medicine. Structural and fluidic simulations were used to design the geometry of the device before manufacturing. After devices have been characterized experimental results demonstrate the credibility of the design, the accuracy of the flow rate and the long-term stability of the device. One application of this device is the replacement of the flow restrictor in an elastomeric infusion system, which will increase the accuracy and safety of the drug delivery system. This pressure compensating flow regulator is passive, hence it needs no external energy source. The device is relatively inexpensive to manufacture and is therefore, potentially a disposable unit in a microfluidic system. Finally, it is small and lightweight, ideal for portable applications.