A high-performance silicon micropump for disposable drug delivery systems

This paper describes the design, fabrication and experimental results of a new, low cost, high-performance silicon micropump developed for a disposable drug delivery system. The pump chip demonstrates linear and accurate (+/-5%) pumping characteristics for flow rates up to 2 ml/h with intrinsic insensitivity to external conditions. The stroke volume of 160 nl is maintained constant by the implementation of a double limiter acting on the pumping membrane. The actuator is dissociated from the pump chip. The chip is a stack of three layers, two Pyrex wafers anodically bonded to the central silicon wafer. The technology is based on the use of SOI technology, silicon DRIE and the sacrificial etch of the buried oxide in order to release the structures. The result is a small size chip, suitable for cost-effective manufacturing in high volume. The micropump chip is integrated into the industrial development of a miniature external insulin pump for diabetes care.