Microsystems efficiency

It is important to note that the enhancements mentioned above are achievable using current planar microfabrication techniques and the resultant sensor chips are mass-producible, low-cost and disposable and also have the potential to be integrated into a variety of diagnostic microsystems. This work has significant implications for the production of low-cost, yet efficient measurement platforms for applications in modem society. 

A wide range of conttol systems is used in household appliances. A standard conttol loop consists of sensors, control units and actuators. The appliances become more powerful and efficient, as the technology is developed and integrated into microsystems. Matchbox-sized sensors can be equipped with wireless radio transceivers and their own miniature operating system to tiansmit continuous data to the facility manager. 

A unique micro integration methodology has been shown for a wide variety of chemical systems. The methodology comprises MUOs, CFCP, and TLM. Some of its applications, which were hardly realized with conventional microsystems based on electrophoresis and LIF detection, were explained with examples. All these examples proved that micro chemical systems drastically reduce chemical processing time and improves efficiency. The micro chemical systems are concluded to be promising as flexible, smart, and mobile advanced chemical systems in near-future chemical technology. 

Electric fields can be used, for instance, to reduce fouling phenomena in systems involving electrically charged macromolecules (e.g., proteins). In microsystems used for capillary zone electrophoresis an external electric field applied across the capillary tube induces electrostatic repulsion between the macromolecules and the inner surface. The reduced adsorption of macromolecules enhances separation resolution and efficiency. 

Fast mass transfer at the phase boundary Another characteristic feature of microsystems derived from their much greater surface-to-volume ratios is that they make phase boundary reactions such as gasdiquid, liquid/liquid or solid/liquid reactions more efficient. The rate of mass transfer increases with an increase in the phase boundary surface-to-volume ratio. 

Generally, one would consider the use of microsystems for gas/gas mixing excessive. Large-scale turbulent mixers handle this task with relatively high efficiency at a far lower cost. There does not appear to be a need for further intensification. 

The ideal system would integrate all of the processing steps into a single platform to provide efficient and fast analysis of the sample with minimum need for operator intervention and sample handling. A view of such a system is shown in Fig. 5. As depicted in Fig. 5, an integrated microsystem would be comprised of several different processing steps (i.e., devices) including ... 

The cross-injector enables analyses with microfabricated systems an order of magnitude faster than capillary-based systems. This advantage is due to the extremely small sample zones that can be injected (<1 nL) with the cross-injector, but the consequence of these minute zones is that the cross-injector is extremely inefficient. Samples are typically pipetted at 1-2 p,L volumes into the drilled reservoirs on a microdevice. Even when considering large injected sample plugs of 1 nL and a low-volume, pipetted sample (1 p.L), the cross-injector is only 0.1% efficient. That is, despite the excellent low-volume fluid-handling promises of microsystems, they still require input volumes... 

Since the development and application of atomistic computational methods in recent years, our understanding of gas microfluidics and nanofluidics has been greatly improved. If the flow and thermal behavior can be correctly analyzed and accurately predicted, optimal design of microsystems is possible. Related work can be found in analyses of the performance of microscale air slide bearings in hard disk drives [16], the propulsion efficiency of micronozzles in... 

In summary, microsystems technology provides efficient tools for the manipulation of cells as well as a high level of control over culture conditions. Thus, robust performance and enhanced reproducibility of assays based on these cultures are anticipated and indeed observed. 

To this end multiphysics simulations have been successfully employed to model and calculate hydrodynamic flow and the associated shear forces, transport phenomena due to diffusion and convection, the effects of Joule heating, as well as electrically induced forces acting on cells for the purpose of organ assembly and the resulting cell trajectories. Using this approach, microsystems may be evaluated with respect to the desired function even before building devices, enabling efficient optimization and acceleration of development [5]. 

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