tailieunhanh - The MEMS Handbook MEMS Applications (2nd Ed) - M. Gad el Hak Episode 1 Part 3

Tham khảo tài liệu 'the mems handbook mems applications (2nd ed) - m. gad el hak episode 1 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 3-2 MEMS Applications devices in catheters that can aid procedures such as angioplasty. Many industrial applications exist that relate to monitoring manufacturing processes. In the semiconductor sector for example process steps such as plasma etching or deposition and chemical vapor deposition are very sensitive to operating pressures. In the long history of using micromachining technology for pressure sensors device designs have evolved as the technology has progressed allowing pressure sensors to serve as technology demonstration vehicles Wise 1994 . A number of sensing approaches that offer different relative merits have evolved and there has been a steady march toward improving performance parameters such as sensitivity resolution and dynamic range. Although multiple options exist silicon has been a popular choice for the structural material of micromachined pressure sensors partly because its material properties are adequate and there is significant manufacturing capacity and know-how that can be borrowed from the integrated circuit industry. The primary focus in this chapter is on schemes that use silicon as the structural material. The chapter is divided into six sections. The first section introduces structural and performance concepts that are common to a number of micromachined pressure sensors. The second and third sections focus in some detail on piezoresistive and capacitive pick-off schemes for detecting pressure. These two schemes form the basis of the vast majority of micromachined pressure sensors available commercially and studied by the MEMS research community. Fabrication packaging and calibration issues related to these devices are also addressed in these sections. The fourth section describes servo-controlled pressure sensors which represent an emerging theme in research publications. The fifth section surveys alternative approaches and transduction schemes that may be suitable for selected applications. It includes a few schemes that have .