TAPERED MICROVALVES FABRICATED BY OFF-AXIS X-RAY-EXPOSURES

A method for creating angled structures for use in microvalve devices applicable to control of liquid flow is presented. This technique util izes a modified LIGA process with successive angled and rotated exposu res into free standing acrylic sheets to form a tapered valve seat str ucture. These valve seats are integrated with bulk micromachined silic on diaphragms and tapered PMMA valve bosses to complete the microvalve . The long term goal of this research effort is to develop a normally- closed, low power, microfabricated valve for use in an implantable dru g delivery system. This paper reports on the design and fabrication of microvalves using off-axis LIGA exposures. Flow testing and fluid han dling characterization results are also presented.