As miniaturization technologies have improved for the past few decades, electronic devices are becoming smaller and the technology needed to fabricate complex three-dimensional (3D) microstructures becomes important. Photolithography is a relatively simple and low-cost method. However, photolithography is, in general, a fabrication method for planar two-dimensional microstructures. In this study, a technique using photolithography is developed to fabricate three-dimensional blades for axial microfan applications. Fabrication of a five-layer SU-8 microstructure for a miniature axial fan of 5 mm diameter using ultraviolet (UV) lithography is presented. Each SU-8 layer was fabricated with a small shift relative to the previous layer. Hence, 3D SU-8 blades with oblique sections have been successfully fabricated using this relatively simple UV lithography. A multiple resist coating and exposure with a single development stage was employed. It was observed that the exposure time for the second to fifth layers was reduced by a factor of 0.7 as compared to that needed for the first layer. A relatively efficient method for the fabrication of multilayer oblique walls was developed. It is probably the first time that UV lithography is used for creating 3D sloping microstructures.
Three examples of different applications of laser techniques in experimental fluid mechanics are described including flow field around a proposed heart prostheses, flow field around a model motor vehicle, and flow visualization of the vortex shedding from a delta wing. Velocity measurements of flow around the heart valve prosthesis indicate that the new design is capable of delaying flow separation. Velocity measurements of flow around a model motor vehicle show that separation occurs above the bonnet and at the rear of the vehicle.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.