Microelectromechanical systems

About: Microelectromechanical systems is a research topic. Over the lifetime, 10255 publications have been published within this topic receiving 151342 citations. The topic is also known as: MEMS & microelectromechanical system.

Micromachined pressure sensors: review and recent developments

Abstract: Since the discovery of piezoresistivity in silicon in the mid 1950s, silicon-based pressure sensors have been widely produced Micromachining technology has greatly benefited from the success of the integrated circuit industry, borrowing materials, processes, and toolsets Because of this, microelectromechanical systems (MEMS) are now poised to capture large segments of existing sensor markets and to catalyse 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 surface-micromachined, optical, resonant, and smart pressure sensors Considerations for diaphragm design will be discussed in detail, as well as additional considerations for capacitive and piezoresistive devices Results from surface-micromachined pressure sensors developed by the authors will be presented Finally, advantages of micromachined sensors will be discussed

Piezoelectric MEMS sensors: state-of-the-art and perspectives

Abstract: Over the past two decades, several advances have been made in micromachined sensors and actuators. As the field of microelectromechanical systems (MEMS) has advanced, a clear need for the integration of materials other than silicon and its compounds into micromachined transducers has emerged. Piezoelectric materials are high energy density materials that scale very favorably upon miniaturization and that has led to an ever-growing interest in piezoelectric films for MEMS applications. At this time, piezoelectric aluminum-nitride-based film bulk acoustic resonators (FBAR) have already been successfully commercialized. Future innovations and improvements in inertial sensors for navigation, high-frequency crystal oscillators and filters for wireless applications, microactuators for RF applications, chip-scale chemical analysis systems and countless other applications hinge upon the successful miniaturization of components and integration of piezoelectrics and metals into these systems. In this article, a comprehensive review of micromachined piezoelectric transducer technology will be presented. Piezoelectric materials in bulk and thin film forms will be reviewed and fabrication techniques for the integration of these materials for microsensor applications will be presented. Recent advances in various piezoelectric microsensors will be presented through specific examples. This review will conclude with a critical assessment of the future trends and promise of this technology.

Mechanics of microelectromechanical systems

Abstract: Stiffness Basics.- Microcantilevers, Microhinges, Microbridges.- Microsuspensions.- Microtransduction: Actuation and Sensing.- Static Response of Mems.- Microfabrication, Materials, Precision and Scaling.

Thermoelectric microdevice fabricated by a MEMS-like electrochemical process.

Abstract: Microelectromechanical systems (MEMS) are the basis of many rapidly growing technologies, because they combine miniature sensors and actuators with communications and electronics at low cost. Commercial MEMS fabrication processes are limited to silicon-based materials or two-dimensional structures. Here we show an inexpensive, electrochemical technique to build MEMS-like structures that contain several different metals and semiconductors with three-dimensional bridging structures. We demonstrate this technique by building a working microthermoelectric device. Using repeated exposure and development of multiple photoresist layers, several different metals and thermoelectric materials are fabricated in a three-dimensional structure. A device containing 126 n-type and p-type (Bi, Sb)2Te3 thermoelectric elements, 20 microm tall and 60 microm in diameter with bridging metal interconnects, was fabricated and cooling demonstrated. Such a device should be of technological importance for precise thermal control when operating as a cooler, and for portable power when operating as a micro power generator.