Papers by Keyword: Micro Pump

Abstract: Ferrofluids are colloidal mixtures which consist of nanosized magnetic particles suspended in a base fluid. The typical magnetic particles could be maghemite, magnetite or cobalt ferrite etc. To keep a ferrofluid suspension in a stable state is possible by an electrical double layer or by adding surfactant. They have many applications on electrical, mechanical and optical systems. Recently, the ability of being manipulated by an external magnetic field made them considerable for microfluidic systems such as micro operations, pumping and mixing. Among them, micro scaled pumping systems have appeared as a critical research area due to its notable potential to be applied on many biological and electronic systems. Moreover, the development of lab on a chip and the micro total analysis systems for biological issues has revealed the necessity of liquid transport for micro quantities. Micropumps with ferrofluid plug actuation mechanisms are considered to have the ability to fulfill this requirement. Therefore, driving the working fluids with ferrofluid plugs in a micro-sized tube or channel has attracted researchers’ interest. In this study, ferrofluid plug actuated micro pumping systems have been reviewed from the available literature based on their design and their maximum generated flow rate.

Abstract: Due to the rise of biological and MEMS technology in recent years, some micro flow system components have been paid attentions to developed by many investigators. The importance of micro-pumps manufactured is higher than the other part of micro flow system since it is the power source of the entire micro-flow system and responsible for driving working fluid in the microfluidic system. In actual operation, the instability and bad dynamic characteristics of the micro-pump will cause larger fluid flow mobility error, such as transport behavior and response procedures failure, etc., and even damage the microfluidic system. Therefore, to investigate the stability and dynamic characteristics of a micro pump is necessary. The miniature piezoelectric film micro-pump, made by Microjet Technology Co., Ltd., is employed to study in this work. The computer graphics software SolidWorks is used to build the model of the micro pump. Then, The Finite element analysis (FEA), ANSYS Workbench, is also employed to analyze the dynamic characteristics of this micro pump.

Abstract: low pumps have been developed for classical applications in Engineering and medicine. They are vital instruments in areas such as Biology where the applications demand many such devices in miniaturized form to handle life saving fluids and drugs. The aim of this paper is to develop a new bio-mimic fluid pump, designed to achieve miniaturization in its size and volume. A new actuation technique is proposed which pumps the fluid based on the principle of flow due to pressure difference created by varying the cross-section of a flexible tube. The novelty and advantage being, no external pressurizing device is needed and the flow can be made bidirectional. This is in general not possible in normal or traditional pumps. Use of SMA wires as actuators helps in keeping the size and weight of the device as low as possible. The working principle of the device and the conceptual design are discussed. Mathematical model, relating the flow parameters required for controlling the device, and analytical results obtained from such relations are presented.

Abstract: Structure and work principle of micro pump developed with shape memory alloy (SMA) materials are introduced. The math model is established to analyze the basic performance parameters. The pressure distributions of the diffuser and the nozzle of valve-less micro-pump were analyzed theoretically,the basic flow equations were obtained.The finite element method was applied to calculate the velocity and pressure fields of the diffuser and the nozzle numerically,and the factors which influences the flow characteristic of the valve-less micro-pump were investigated. Simulating the actuator deformations of the micro pump, The feasibility of the operation prineiple and design method of the valveless Pump driven by the SMA actuator has been Proved by the analysis and test results.The result shows that the micro pump based on SMA materials has some advantages of fast response, large flex displacement and high control precision ,etc.

Abstract: The authors have developed a miniaturized peristaltic pump which is characterized by multi-channel, low pulsation, high pressure resistance and portability. The pump mainly consists of a disposable pumping channel unit and reusable actuating parts. The pumping channel unit, made of silicone elastomers, has eight pumping channels. The operation principle is based on the peristaltic motion of pumping channels that are occluded by the screw shaft. The shaft rotating inside the pumping channel unit has a spirally arranged projection which deforms and closes down the channels. While the shaft rotates, the pinched locations in the channels move either way according to direction of rotation, squeezing out the air inside. The maximum discharge pressure generated was about 160 kPa at rotating speeds of 30 ~ 180 rpm. A micro pneumatic actuator was fabricated to demonstrate the performance of the pump. The validity of the pump for pneumatic actuation was reported.

Abstract: Micro pumps are essential components of micro-fluidic systems and bio-sensing systems. In particular, the micro pump used for -TAS transports fluids at a micro flow rate with high precision. This micro pump is also used to transport high-viscosity fluids because there are various types of drugs to be transported. We developed a micro pump driven by a conducting polymer soft actuator that opens and closes. Although the developed micro pump contains no valve, the micro pump can transport fluids in one direction without backflow. A newly developed micro pump driven by a conducting polymer soft actuator can transport fluids in one direction without backflow by the opening and closing of two soft actuators.

Abstract: Being as a functional material, piezoelectric ceramics is applied to drive a micropump when it is composed to be a thin membrane on a brass film to form a diaphragm. According to the properties of the piezoelectric material, the stiffness of the diaphragm influences the vibration displacement and therefore the supply flow rate of the micropump. This paper focuses on the dynamic characteristic study of the micropump and the stiffness influence of the diaphragm on the characteristics. The mathematical model of the valve-less micropump considering the diaphragm stiffness is developed in order to predict the dynamic characteristics of the piezoelectric valve-less micropump. Using the 3-D finite element analysis (FEA) method, the static and vibration mode of the diaphragm are analyzed to obtain the diaphragm stiffness and natural frequency. The method using Matlab is to predict the pressure and flow rate characteristics of the micropump when the diaphragm stiffness is considered or not. Comparison of the simulation results shows the stiffness of the diaphragm influences the dynamic characteristics of micropumps. It also shows that the method combining FEA software with Matlab provides a possible and effective tool to take the diaphragm stiffness into account when the pressure and flow rate characteristics of micropumps are studied.

Abstract: This paper presents a valve-less micropump which is actuated by a piezoelectric ceramic chip. We employ a microelectromechanical system process for the silicon substrate and anodic bonding for assembly of the Pyrex glass and silicon wafer. The reciprocating type micropump contains two nozzle/diffuser elements and a silicon membrane with an embedded piezoelectric ceramic actuator.

Abstract: In this paper, the pumping performance of a piezoelectric micropump is simulated with commercial finite element analysis (FEA) software COMSOL Multiphysics 3.2a. The micropump is composed of a 4-layer piezo-composite actuator (LIPCA), a polydimethylsiloxane (PDMS) pump chamber, and two diffusers. The piezoelectric domain, structural domain and fluid domain are coupled in the simulation. Water flow rates are numerically predicted for geometric parameters of the micropump. Based on this study, the micropump is optimally designed to obtain its better pumping performance.

Abstract: We propose a new PDMS microfluidic system including microvalves and a micropump that are easily integrated on the same substrate with the same process steps. The pumping rate of the fabricated microfluidic system was measured under various frequency and duty-ratio of applied power. The maximum pumping rate of about 26 nl/min is measured under the duty ratio of 1 % at 2 Hz of the applied pulse voltage. The dynamic response of the microvalve in the microfluidic system is measured under the on/off alternation with the applied power of 100 mW.