ABSTRACT

There can be both advantages and disadvantages in miniaturizing transducers that are commonly used for biosensors. For discrete sampling instruments, small sample volumes are often desirable. Detailed spatial resolution may be required for some applications. If the biosensor is intended for direct measurements in living tissues, it must be small enough to minimize damage to the cells or to the microcirculation in the tissue. If placed directly into the bloodstream, it must not impede blood flow. Smaller devices may be less durable and easier to break than larger ones. Finally, miniaturized transducers often have much more rapid response times than are possible with larger devices. However, the signals may also be smaller and more difficult to detect from miniaturized devices. A great amount of research effort has been spent in developing reliable fabrication techniques for miniaturizing electrochemical and optical transducers for conventional types of measurements as well as for biosensors.