Papers by Author: Juliana Johari

Abstract: This paper presents a simple process technique for the fabrication of valveless micro-pumps. The process design utilizes standard MEMS process using double-sided anisotropic silicon wet etching process with an additional adhesive bonding technique. The diffuser and nozzle element of the pump with depth of 50 µm, as well as a 150 µm thick silicon membrane are designed and fabricated using only 3 patterning process steps. A piezoelectric plate working at the frequency range from 0.1 kHz to 2 kHz is bonded on to the back side of the silicon membrane to create the membrane actuation. The patterning process of thick photoresist used as the adhesive layer for the substrate bonding is also discussed in detail. The fluid flow is observed and the process reproducibility is proven which show a good prospect for the future development of miniaturized valveless pump for biomedical application.

Abstract: . In this study, a Piezoelectric Actuated Valveless Micropump (PAVM) has been designed and successfully fabricated using MEMS fabrication processes. A PZT: Pb (ZrTi) Ox (lead titanate zirconate) disc is used to actuate a silicon membrane by applying an alternating electrical field across the actuator. The resultant reciprocating movement of the pump membrane is then converted into pumping effect. Preliminary analysis of the fluidic characteristics of this micropump was performed using CoventorWare Simulator with MEMs-FSI (Fluid Structure Interaction) module to understand the working behaviour of the pump system. The pump is fabricated in a simple micromachining process with two optical masks using a double side polished silicon wafer. The tests carried out on the micropump have produced promising results to be used in the drug delivery system.