The rapid development of microelectromechanical systems (MEMS) technologies in recent years has provided a high degree of spatial miniaturization and integration of electromechanical components, which enable integrated sensing and control in manufacturing. In this paper we presented an overview of the state of the art of micro machined microsensors for the measurement of mechanical signals in the manufacturing industry for automobiles, manufacturing, medical equipment, environment, robotics, food and other consumer products. We will describe major design parameters of such microsensors, such as dynamic range, sensitivity, resolutions and accuracy and provide real world applications. In this paper we also dealt with issues related to the spatial integration of signal processing, power supply, and wireless communication with the sensing elements, which are of direct relevance to the overall performance of the microsensors.
Mechanical signals measured by the microsensors monitor the operational status of the manufacturing equipment, determine the process characteristics, and provide input to the system controller for improving product quality while reducing machine downtime. Measurements of pressure, acceleration, and acoustic emission (AE) are the three physical quantities that are most encountered in industrial and manufacturing applications. We will describe major design parameters of such microsensors, such as dynamic range, sensitivity, resolutions and accuracy and provide a real world application. We will also discuss issues related to the spatial integration of signal processing, power supply, and wireless communication with the sensing elements, which are of direct relevance to the overall performance of the microsensors.
Pressure sensors are among the most popular and important sensing devices, accounting for 40% of the total sales in sensors. Pressure sensors find application in automotive systems manufacturing process control, and medical diagnostics. Over the last decade, the need for micromachined pressure sensors has increased rapidly because of their microscaled dimensions that allow for structural integration into the automobiles and manufacturing equipment. Such integration enables in-situ measurement at the site where actions take place, thus providing a clearer picture of the object to be sensed. This may not be possible using conventional sensors. From the point of view of sensing principles, pressure microsensors can be generally divided into four categories. They are
This paper reviewed microsensors for mechanical measurement applications, focusing on the measurement of pressure, acceleration, and AE. For the pressure microsensors, three major design principles, piezoresistive, capacitive, and optical, were introduced; tire pressure sensors served as an industrial example. For monitoring machine vibrations, the piezoresistive, capacitive, tunneling, and resonant accelerometers were introduced, exemplified by a bearing diagnosis and prognosis system. The application for AE microsensors in precision machining and other manufacturing and nondestructive testing areas were described, with special attention given to capacitive and piezoresistive microphones. In addition, the spatial integration of signal processing, power supply and wireless communication with the sensing elements was discussed, which has significance in improving the overall performance of the microsensors. This review provides a glimpse into how microsensors can help improve the performance of machine, as well as achieve better control of the manufacturing process.