Micro device shape

This micro device consists of a square micro chamber which has as a bottom plate a conventional DNA micro-array chip sealed by a cover slip with double-sided adhesive tape (see Figure 1.26) [24], The adhesive tape serves as a spacing gasket to define the shape and dimensions of the chamber. The cover slip contains the air pockets with a uniform, pitched distribution. The air pockets trap the air bubbles... 

In a conventional design, each unit operation is modeled using terms and values which do not depend on the location inside the device. On the one hand, convection and diffusion in a micro structured device strongly influence the functioning of the device, and on the other hand the convection and diffusion conditions are affected by the shape of the device. To obtain an optimized fluidic micro device, some constraints on the shape of the device are necessary. These are constraints, e.g., on the average residence time, the residence time distribution and the temperature distribution [13]. 

Gaakeer, W., de Croon, M., van der Schaaf, J., Schouten, J. (2012). Liquid-liquid slug flow separation in a slit shaped micro device. Chemical Engineering Journal, 207, 440-444. 

By integration of the loeal slopes, we have reconstructed the micro-mirror surface. An example is shown in Fig.4, along the line indicated by an arrow on the slope map. The surface deformations do not exceed 1 nm along the studied profile. Although surface shapes vary from mirror to mirror, deformations in the nanometer range demonstrate the remarkable quality of this device. 

Another type of linear configuration known as bow-tie is shown in Figure 10.10. The actuator is constmcted using dielectric elastomer film having the shape of a bow-tie with two compliant electrodes configured on its two surfaces. Application of the electric field results in planar actuation which because of the bow-tie shape is translated into linear motion. Typical applications of these types of actuators comprise a hexapod robot, to mimic the motion of insects like walking, to manufacture various animated devices like face, eyes, skin, etc., or the design of micro-air vehicle/omithopter. 

Other snare devices that potentially can be used for embolectomy include (1) the Alligator Retrieval Device, which is a retriever with grasping jaws attached to the tip of a flexible wire designed to be used in conjunction with 0.21-inch micro-catheter " and (2) the EnSnare device, which has a tulip-shaped, three-loop design that opens distally. These devices, which are approved for foreign body removal/coil retrieval, have not been reported in embolectomy for stroke treatment. 

Figure 1.14 Schematic representation of a stirred vessel (left) and a T-shaped micro reactor (right). Both devices can be used for liquid/liquid and for gas/liquid reactions. The length scales indicate typical physical dimensions.

Micro-flow processing is not an exclusive domain of micro-channel devices made by micro fabrication. This approach can be applied to any packing of regular-shaped objects which results in interstices of the same internal dimensions and the same precision as given for micro channels. Obviously, interstices made from extended, but thin objects resemble best the nature of micro channels. Hence the use of filaments for constituting a micro-flow assembly was recently described [8]. 

The micro fluidic devices are integrated into cubic modules of identical shape and size, and can be easily replaced [108], The modules are equipped with individual temperature control, integrated pressure and/or temperature sensors and, upon demand, additional actors such as non-return valves. This modular concept ensures a flexible interconnection of the micro fluidic devices. 

Dunges [21] developed the device illustrated in Fig. 2.6 and used it for the performance of micro-reactions that require refluxing. The reactions are carried out (even several at a time) in small test-tubes with various volumes and conical-shaped bottoms. 

Solid phase micro extraction (SPME) is a widely used extraction technique that was developed by Pawlistyn and co-workers in 1990 (74). SPME uses a fused silica fiber that is coated on the outside with an appropriate stationary phase (a S to 100 pm thick coating of different polymers, e.g. polydimethylsiloxane, PDMS). The small size of the SPME flber and its cylindrical shape enables it to fit inside the needle of a syringe-like device. Target molecules from a gaseous or a liquid sample are extracted and concentrated to the polymeric fiber coating. SPME has been used coupled to GC and GC-MS (75), as well as to HPLC and LC-MS 7ll>). Figure 7 shows a conunercially available SPME device. 

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