MEMS/NEMS Devices and Applications

Abstract

Microelectromechanical systems (MEMS) have played key roles in many important areas, for example transportation, communication, automated manufacturing, environmental monitoring, health care, defense systems, and a wide range of consumer products. MEMS are inherently small, thus offering attractive characteristics such as reduced size, weight, and power dissipation and improved speed and precision compared to their macroscopic counterparts. Integrated circuit (IC) fabrication technology has been the primary enabling technology for MEMS besides a few special etching, bonding and assembly techniques. Microfabrication provides a powerful tool for batch processing and miniaturizing electromechanical devices and systems to a dimensional scale that is not accessible by conventional machining techniques. As IC fabrication technology continues to scale toward deep submicron and nanometer feature sizes, a variety of nanoelectromechanical systems (NEMS) can be envisioned in the foreseeable future. Nanoscale mechanical devices and systems integrated with nanoelectronics will open a vast number of new exploratory research areas in science and engineering. NEMS will most likely serve as an enabling technology, merging engineering with the life sciences in ways that are not currently feasible with microscale tools and technologies. MEMS has been applied to a wide range of fields. Hundreds of microdevices have been developed for specific applications. It is thus difficult to provide an overview covering every aspect of the topic. In this chapter, key aspects of MEMS technology and applications are illustrated by selecting a few demonstrative device examples, such as pressure sensors, inertial sensors, optical and wireless communication devices. Microstructure examples with dimensions on the order of submicron are presented with fabrication technologies for future NEMS applications. Although MEMS has experienced significant growth over the past decade, many challenges still remain. In broad terms, these challenges can be grouped into three general categories: (1) fabrication challenges; (2) packaging challenges; and (3) application challenges. Challenges in these areas will, in large measure, determine the commercial success of a particular MEMS device in both technical and economic terms. This chapter presents a brief discussion of some of these challenges as well as possible approaches to addressing them.