Development of MEMS-based cerebrospinal fluid shunt system

We have developed a micro cerebrospinal fluid (CSF) shunt system with a MEMS-based micro CSF shunt valve. This valve consists of flow nozzles with membrane connected to anchor by bridges. The up-down movement of the membrane turns the CSF on and off, and the thickness and shape of bridges and membrane determine the valve characteristics, such as opening pressure. The membrane, anchor and bridges were made of micro patterned Parylene™ film. To make the membrane and bridge not be torn out in the CSF flow, we added a cover layer. The total dimension of the assembled CSF shunt valve is 2.5 × 2.5 mm² , and 0.8 mm in height. The burst pressure and flow rate of the valve were precisely controled by carefully selecting the design parameters, such as the thickness of membrane and bridge, and the width and number of the bridge. The developed CSF shunt system showed good performances in the evaluation test for commercialized CSF shunt systems.