Micromachined pressure sensors: review and recent developments

Abstract

Since the discovery of piezoresistivity in silicon in the mid 195Os, silicon-based pressure QsS;i%vI been widely produced. Micromachining technology has greatly benefited from the success of the integrated circuits industry, borrowing materials, processes, and toolsets. Because of this, microelectromechanical ystems (MEMS) are now poised to capture large segments of existing sensor markets and to catalyze the development of new markets.Given the emerging importance of MEMS, it is instructive to review the history of micromachined pressure sensors, and to examine new developments in the field. Pressure sensors will be the focus of this paper, starting from metal diaphragm sensors with bonded silicon strain gauges, and moving to present developments of surfacemicromachined, optical, resonant, and smart pressure sensors. Considerations for diaphragm design will be discussed in detail, as well as additional considerations for capacitive and piezor esistive devices.

Inflatable shape changing colonies assembling versatile smart space structures

“…Ideally, each sensor (like the microvalve) would require minimal electrical routing and a fabrication scheme that would fit well within the overall cell fabrication process. A number of existing micromachined pressure sensor designs are available [18]; for our design, we have chosen a capacitive pressure sensor due to the relative increased pressure sensitivity and decrease temperature sensitivity when compared to other sensor types [18]. A diagram for this pressure sensor is given in Figure 9.…”

Ultrasonic Transducers

“…During the past decades, many micromachining processes have been proposed for the fabrication of cMUTs [9][10][11][12][13][14][15][16][17][18][19]. These processes can be divided into two catalogs: surface process and bulk process.…”

“…Meanwhile, a different surface process was developed in Sandia National Laboratories [11][12][13][14][15]. The main features of this process are double sacrifice layer design for quick membrane releasing, and additional Chemical Mechanical Polishing (CMP) step for surface planarization.…”

Review on Micro- and Nanolithography Techniques and their Applications

“…Not only micro-and nanolithography has been the main driving technology in the semiconductor and IC industry, it also plays an increasingly important role in manufacturing of commercial microelectromechanical system (MEMS) devices [45][46][47][48][49][50] as well as prototype fabrication in emerging nanoscale science and engineering [51][52][53][54][55][56]. These applications are expected to significantly improve our quality of lives in many ways from electronic gadgets to healthcare and medical devices.…”

“…These applications are expected to significantly improve our quality of lives in many ways from electronic gadgets to healthcare and medical devices. Some examples of commercial MEMS products include MEMS accelerometers employed in automobiles and consumer electronic devices [45,46], digital micromirror devices (DMD) for display applications in projectors and televisions [45,47,48], and MEMS pressure sensors for detecting pressures in car tires and blood vessels [49,50]. Furthermore, nanoscience and engineering has increasingly contributed to conventional technologies by opening up alternative routes to overcome current technical barriers, to name a few of them, nanoelectronics for denser and faster computing, nanomedicine for diagnosis and treatment of many diseases including cancers [51][52][53][54], heart disease and Alzheimer's disease [55,56], nanoelectromechanical systems for high-sensitivity and high-resolution sensing and manipulating, and nanobiosensors for ultra-low concentration and single molecular detection.…”