Fabrication of components for a valve-less micropump or microejector by multilevel electroforming technology

Abstract

Both the workable micropump and microejector actuated by the shear mode PZT actuators are successfully fabricated. They are based on a similar design and the same process that uses UV-LIGA multilevel electroforming technology. The micropump consists of a vibration plate and a chamber plate while the microejector consists of the same vibration plate and a nozzle plate. The AZ 9260 positive photoresist is used as the electroforming mould. The two alternating steps, the photoresist patterning and nickel electroforming, make components form a quasi 3D (or 2.5D) multilevel microstructure. An over-electroforming technique is employed to form the nozzles in nozzle plate for the microejector. Some useful experimental data about the over-electroforming are proposed to predict and control the orifice diameter. The volume change of the chamber is estimated by both the numerical solution and actual measurement. The liquid ejection of the microejector is observed by a visualization system.

Photoresist Deposition and Nickel Electrodeposition for Metallic Substrate Microfabrication with Nickel Lines

“…Protocol with AZ 9260 photoresist AZ 9260 is a positive photoresist designed for film thickness from 2 μm to 24 μm resolution [16]. Photolithography with AZ 9260 photoresist consisted: AZ 9260 Photoresist was deposited on a metallic substrate.…”

Design and fabrication of novel micro electromagnetic actuator

“…Broadly speaking, the micro actuators presented in the literature can be categorized as either static, electromagnetic, or piezoelectric (Liu et al 1994;Lagorce et al 1999;Yamahata et al 2005;Zhu et al 2005;Xu et al 2006;Chen et al 2007;Ma et al 2008). Liu et al (1994) fabricated a system of magnetic flaps intended for use in an active MEMS-based fluid control system.…”

“…Meanwhile, Xu et al (2006) presented a monolithic Pb(ZrTi)O 3 -actuated multiple degree-of-freedom micro-stage for high-precision positioning applications. Chen et al (2007) utilized UV-LIGA multilevel electroforming techniques to fabricate piezoelectrically-actuated micropumps and micro-ejectors, and demonstrated experimentally that displacements as high as 250 nm could be achieved by applying a 120-V pp sinusoidal waveform with a frequency of 1 kHz.…”