Fluid micropump

One of the earliest types of rotary micropumps developed for microfluidics applications, drug delivery in particular, is the jet-type magnetically driven fluid micropump. It is based on a rotary micromotor which is attached to a toothed rotor (Fig. 1). Basically, it is a micro version of conventional positive displacement pump. Flow rates up to 24 pL/min at a pressure of 10 kPa have been obtained using this design [4]. 

A fluid micropump widi the other structure (Naka et al. 2010), namely, peristaltic movement, was fabricated using PPy films. The micropump was composed widi two serially arranged open-close micropumps widiout valves. The serial micropumps were driven alternatively to push the fluid in one direction by taking the synchronous... 

Keywords Microsystem, (bio)chemical analysis, fluid handling, pTAS, micropump. ... 

Because of the enormous diversity in components it is difficult to describe a straightforward design-path for components for the MCB concept. Here we focus on the modeling and the design of the fluid control modules and specific on the thermo-pneumatic actuated micropump used (twice) in the demonstrator. An elaborated model of this micropump is given by van de Pol et al. [21]. The main functions of the fluid control in micro analysis systems are the switching function and the direct flow and/or pressure control. Building blocks are hydraulic inertances, resistors, capacitors and passive and control-valves. Very often an active element like a micropump is needed. 

Several techniques for miniaturization of simple chemical and medical analysis systems are described. Miniaturization of total analysis systems realizes a small sample volume, a fast response and reduction of reagents. These features are useful in chemical and medical analysis. During the last decade many micro flow control devices, as well as the micro chemical sensors fabricated by three dimensional microfabrication technologies based on photofabrication, termed micromachining, have been developed. Miniaturized total analysis systems (pTAS) have been studied and some prototypes developed. In microfabricated systems, microfluidics , which represent the behavior of fluids in small sized channels, are considered and are very important in the design of micro elements used in pTAS. In this chapter microfluidics applied flow devices, micro flow control devices of active and passive microvalves, mechanical and non-mechanical micropumps and micro flow sensors fabricated by micromachining are reviewed. 

A ferrofluidic magnetic micropump was constmcted on a Si chip. Operation relies on the use of magnetically actuated plugs of ferroliquid (a suspension of nano-sized ferromagnetic particles), which is immiscible with the pumped fluid [301],... 

Fig. 6.5. Principle of a valve-based micropump. Membrane deflection in a micropump displaces fluid through one of two integrated check valves.

Fluid flow is controlled using solenoid isolation valves V ( 075T2NC12), diaphragm micropump P ( 120SPI12), and a 3-way pinch valve PV ( 075P3MP12). These devices were purchased from Bio-Chem (http //www.Bio-Chem.com). The system can either be run in a manual mode with full control or in batch mode for user-free operation. The latter is based on a 24 vial holder carousel, with rotational and up-down stepper motors. 

The term pTAS is sometimes interchanged with lab-on-a-chip (LOG), more often when the manipulation of fluids is involved. pTAS and LOG range in size from a few microns to a few millimetres. The technique of pTAS is interdisciplinary it combines the advantages of chemical sensors and the resolving power of modem benchtop analytical systems and is constantly evolving. The main advantage of pTAS is integration of the entire separation process onto one analytical microdevice, so early efforts focused on micropumps and valves to manipulate fluids inside a microfabricated structure. In such a fluid-based pTAS,... 

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