Fluid micropumps based on rotary magnetic actuators

Microsystem Technologies, 2009

This paper briefly reviews recent research and developments of micropump designs with a particular emphasis on mechanical micropumps and summarizes their applications in biomedical fields. A comprehensive description of the actuation schemes, flow directing concepts and liquid chamber configurations for micro pumping is provided with illustrative diagrams. Then, a comparative study of current mechanical micropump designs highlighting their advantages and limitations for various applications is presented, based on performance criteria such as actuation voltage and power consumption, ranges of operating frequency and maximum flow rate and backpressure. This study compiles and provides some basic guidelines for selection of the actuation schemes and flow rate requirements in biomedical applications. Different micropumps in biomedical applications, such as blood transport and drug delivery also have been reviewed.

International Journal of Applied Electromagnetics and Mechanics, 2007

A novel micropump using oscillation of an elastic film has been proposed for medical applications. The shape of the pump is a cylinder with outside diameter of 4 mm and length of 29 mm. The moving part of the pump is an angular oscillator composed of a magnet and an elastic film. When external alternating magnetic fields are applied, the magnet oscillates due to magnetic torque and then the elastic film can generate flow. The prototype micropump exhibited the maximum flow rate of approximately 100 ml/min.

Micromachines, 2017

A valveless electromagnetic (EM) micropump with a matrix-patterned magnetic polymer composite actuator membrane structure was successfully designed and fabricated. The composite membrane structure is made of polydemethylsiloxane (PDMS) that is mixed with magnetic particles and patterned in matrix blocks. The matrix magnetic composite membrane was fabricated using a soft lithography process and expected to have a compact structure having sufficient magnetic force for membrane deformation and maintained membrane flexibility. The magnetic membrane was integrated with the microfluidic system and functionally tested. The experimental results show that a magnetic composite actuator membrane containing of 6% NdFeB is capable of producing a maximum membrane deflection up to 12.87 µm. The functionality test of the EM actuator for fluid pumping resulted in an extremely low sample injection flow rate of approximately 6.523 nL/min. It was also concluded that there is a correlation between the matrix structure of the actuator membrane and the fluid pumping flow rate. The injection flow rate of the EM micropump can be controlled by adjusting the input power supplied to the EM coil, and this is believed to improve the injection accuracy of the drug dosage and have potential in improving the proficiency of the existing drug delivery system.

Journal of micromechanics and …, 2004

We survey progress over the past 25 years in the development of microscale devices for pumping fluids. We attempt to provide both a reference for micropump researchers and a resource for those outside the field who wish to identify the best micropump for a particular application. Reciprocating displacement micropumps have been the subject of extensive research in both academia and the private sector and have been produced with a wide range of actuators, valve configurations and materials. Aperiodic displacement micropumps based on mechanisms such as localized phase change have been shown to be suitable for specialized applications. Electroosmotic micropumps exhibit favorable scaling and are promising for a variety of applications requiring high flow rates and pressures. Dynamic micropumps based on electrohydrodynamic and magnetohydrodynamic effects have also been developed. Much progress has been made, but with micropumps suitable for important applications still not available, this remains a fertile area for future research.

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2021

In this paper we present the development of electromagnetic (EM) microfluidic pumps incorporating the magnetic polymer composite for the transport of microfluidic bio-sample. The pump system includes the electromagnetic field generator, a flexible actuator membrane made of polymer material with embedded magnetic particles and valve-less microfluidic channel and chamber. The micropump is fabricated using a MEMS process with additional bonding process. Various types of the magnetic membrane as well as electromagnetic coils were fabricated and characterized to find optimum pump performance. As the results, it is found that the fabricated pump systems were able to deliver fluidic sample within a large flow-rate range from 6 ml/min down to several nl/min which can be adjusted by setting the input electrical current parameters, such as intensity, frequency and type of the current signal.

Advances in Materials and Processing Technologies, 2017

Piezo-electrical diaphragm type mechanical micro pump (PZT micro pump) is one of the Micro Electro Mechanical System (MEMS) device dominant among all micro pumps because of its simple structure and low power consumption. PZT micro pump is widely used for drugdelivery systems basically-injection of glucose to diabetic patients and blood transportation, and also in other areas such as bioengineering, fuel drop generator for automobile heaters, micro metering valves for fuel injection system, etc. Fluid flow from these micro pumps is in the form of small discrete volumes with flow pulsating. But in application such as drug delivery system it may be required to have a continuous fluid flow without any flow pulsation. Therefore to have an adaptability of these micro pumps for drug-delivery applications, problem of pulsating flow can be overcome by proper sequencing of these pumps. In the present paper, an attempt has been made to study the multiple PZT micro pumps operated in parallel connection with sequential switching in order to reduce the flow pulsation. The flow pulsations have been measured in terms of pressure pulsation and average flow rate and obtained results are presented systematically in the paper.

Advanced Technologies & Materials

This paper presents an overview of an improved solution for an existing micropump model and, also, of the materials recommended to be used in the current stage of the prototype research. This micropump is provided with a closed system for driving and pumping the fluid, obtained by a special constructive solution, where the rotation of the motor shaft is provided by induction of a magnetic field. The micropump system is composed by an external driving and an internal driven magnet, connected to a pair of gears that moves the fluid between the inlet and outlet apertures. These magnets are separated by a metal cover that provides a closed volume for the transported fluid with no need for supplementary sealing, as in the case of classical hydraulic pumps. Due to this constructive solution and to the applicative fields where these magnetic drive micropumps operate, their components are produced from compatible materials to provide a low friction/wear and high efficiency in use

Journal of Microelectromechanical Systems, 2001

A microfluidic pump is described that uses magnetic actuation to push fluid through a microchannel. Operation relies on the use of magnetically-actuated plugs of ferrofluid, a suspension of nanosize ferromagnetic particles. The ferrofluid contacts but is immiscible with the pumped fluid. The prototype circular design demonstrates continuous pumping by regenerating a translating ferrofluidic plug at the conclusion of each pumping cycle. The flow rate can be controlled by adjusting device dimensions or the velocity of an external permanent magnet that directs the motion of the ferrofluid. The ferrofluidic plugs also serve as valves; if the magnetic actuator is stopped, pressure can be maintained with no power consumption. Flow can also be reversed by switching the direction of actuation. The maximum flow rate achieved with minimal backpressure was 45.8 l/min. The maximum pressure head achieved was 135 mm water (1.2 kPa).

Scientific reports, 2018

We propose a new class of magnetically actuated pumps and valves that could be incorporated into microfluidic chips with no further external connections. The idea is to repurpose ferromagnetic low Reynolds number swimmers as devices capable of generating fluid flow, by restricting the swimmers' translational degrees of freedom. We experimentally investigate the flow structure generated by a pinned swimmer in different scenarios, such as unrestricted flow around it as well as flow generated in straight, cross-shaped, Y-shaped and circular channels. This demonstrates the feasibility of incorporating the device into a channel and its capability of acting as a pump, valve and flow splitter. Different regimes could be selected by tuning the frequency and amplitude of the external magnetic field driving the swimmer, or by changing the channel orientation with respect to the field. This versatility endows the device with varied functionality which, together with the robust remote contr...

Sensors and Actuators B: Chemical, 2008

This paper briefly overviews progress on the development of MEMS-based micropumps and their applications in drug delivery and other biomedical applications such as micrototal analysis systems (TAS) or lab-on-a-chip and point of care testing systems (POCT). The focus of the review is to present key features of micropumps such as actuation methods, working principles, construction, fabrication methods, performance parameters and their medical applications. Micropumps have been categorized as mechanical or non-mechanical based on the method by which actuation energy is obtained to drive fluid flow. The survey attempts to provide a comprehensive reference for researchers working on design and development of MEMS-based micropumps and a source for those outside the field who wish to select the best available micropump for a specific drug delivery or biomedical application. Micropumps for transdermal insulin delivery, artificial sphincter prosthesis, antithrombogenic micropumps for blood transportation, micropump for injection of glucose for diabetes patients and administration of neurotransmitters to neurons and micropumps for chemical and biological sensing have been reported. Various performance parameters such as flow rate, pressure generated and size of the micropump have been compared to facilitate selection of appropriate micropump for a particular application. Electrowetting, electrochemical and ion conductive polymer film (ICPF) actuator micropumps appear to be the most promising ones which provide adequate flow rates at very low applied voltage. Electroosmotic micropumps consume high voltages but exhibit high pressures and are intended for applications where compactness in terms of small size is required along with high-pressure generation. Bimetallic and electrostatic micropumps are smaller in size but exhibit high self-pumping frequency and further research on their design could improve their performance. Micropumps based on piezoelectric actuation require relatively high-applied voltage but exhibit high flow rates and have grown to be the dominant type of micropumps in drug delivery systems and other biomedical applications. Although a lot of progress has been made in micropump research and performance of micropumps has been continuously increasing, there is still a need to incorporate various categories of micropumps in practical drug delivery and biomedical devices and this will continue to provide a substantial stimulus for micropump research and development in future.