The microvalve for the hydraulic actuatora need large flow rate (>10 cc/second, displacement related), high-pressure support ability (>10 MPa) and a high operational frequency (>10 kHz) [1, 2]. Microvalves can match the piezoelectric material’s frequency, due to the scaling laws. Robust nanostructured metallic microvalves are greatly needed, since both the ultimate strength and the fracture toughness are important in this application. Authors have developed a novel self-assembled micro check valves using the electroformed nano-structured nickel as the functional material. The overall valve is self-assembled pure nickel, but it consists of three parts in detail: the supporting substrate (Figure 1 b and c) containing inlet channels, micro flaps and the valve stopper (containing outlet channels, Figure 1 c). A novel in situ UV-LIGA fabrication process was elaborated to fabricate the nanostructured nickel microvalve. Thick photoresist (SU-8) and thin photoresist were employed as the micro molds and sacrificial material defined by photolithography. Nickel electroforming was conducted to fabricate all components of the valve. Self-assembling was realized by guiding electroforming process during the fabrication. The final valves were received after removing all the sacrificial materials.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2005 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: May 8, 2005
Pages: 479 - 482
Industry sectors: Advanced Materials & Manufacturing | Sensors, MEMS, Electronics
Topics: MEMS & NEMS Devices, Modeling & Applications