Abstract:
Microelectromechanical systems (MEMS) based piezoelectric (PZT) micropump has been extensively used in medical field for last few years. PZT micropump exhibits high flow rate that is suitable for various medicinal applications. In this paper, the structural analysis of polydimethylsiloxane (PDMS) membrane has been presented that was performed using ANSYS software. Membrane is major part of piezoelectric micropump as it directly interacts with fluid and provides the force for required fluidic flow. ANSYS parametric design language (APDL) tool has been used for simulation and analysis. The PDMS membrane with length of 30000 µm (9843 µft), width of 10000 µm (3281 µft) and thickness of 500 µm (1640 µft) to 3000 µm (9843 µft) has been used for analysis. The pressure range of 1-4 kPa (0.15-0.58 psi) has been applied on membrane and the effects of stress and deflection have been observed at various thickness parameters. At applied pressure of 1 kPa (0.15 psi), the deflection of 0.053 µm (0.17 µft) and the stress of 0.65 MPa (94 psi) have been observed. At applied pressure of 4 kPa (0.58 psi), total deflection of 0.211 µm (0.7 µft) and stress of 2.62 MPa (380 psi) have been obtained. The effect of different thickness ranges on the uniform surface of membrane has been studied by applying the pressure. The stress and deflection variations due to thickness changes have been observed. At 250 µm (820 µft) of membrane thickness, the net deflection is observed to be 1.2 µm (3.9 µft). On the other hand, at 2000 µm (6562 µft) thickness, the deflection decreases up to 0.0029 µm (0.0095 µft). It has been observed that the maximum stress of 2.54 µm (8.3 µft) and 0.128 µm (0.42 µft) have been obtained at 250 µm (820 µft) and 2000 µm (6562 µft) thickness of membrane respectively. Thickness is most important parameters in micropump actuator and has direct impact of fluid flow through the micropump outlet. The deflection of membrane can be changed by changing its thickness. Hence micropump can be designed according to the desired requirement such as actuator performance and flow rate. This optimization of membrane can provide useful information to the researcher for fabrication of optimal design of micropump for specific biomedical application like drug delivery, fluid transport and blood transport.