Chemical sensing using nonoptical microelectromechanical systems

Micromachining isa technology that miniaturizes mechanical sensors and actu ators through the use of tools and materials commonly used in the integrate d circuit industry. The physics of the devices formed in this way are somet imes similar and sometimes different to achieve the same functionality of c urrent macroscopic devices, but in sizes that are hundreds or thousands of times smaller. This article will discuss a few chemical detectors being dev eloped as examples of the application of microelectromechanical systems (ME MS) for nonoptical laboratory instruments, Tn this article, we will report on the development and demonstration of two approaches (quadrupole and magn etic Lorentz) to fabricate a mass filter as part of a mass spectrometer. Th is article is, not meant as a review of the field of MEMS chemical sensors, but rather a tutorial on how miniaturization:ls achievable through the use of MEMS fabrication techniques for mass spectrometers. (C) 1999 American V acuum Society, [0734-2101(99)15604-5].