Imagine a tiny speaker as big as a penny, and is entirely made out of silicon. That is the miracle of MEMS. Microsystems that deliver both electrical, as well as mechanical functions, are called Microelectromechanical Systems or MEMS. Built with the same advanced techniques that make today’s integrated circuits, MEMS can range in size from several millimetres to less than one micrometre or to 1000th of a millimetre, hence MEMS are now almost omnipresent. Despite, their impossibly tiny size, MEMS are composed of parts such as microsensors, microprocessors, microactuators, units for data processing and parts that can interact with exterior pieces.
The miniaturization, up to the submicrometer scale, of electronic and optoelectronic components grown on semiconductor substrates generated the computer and communication revolutions at the end of the twentieth century. The miniaturization of electronic components accompanied by the increase in their performances was successful due to a combination of advanced semiconductor technologies such as MBE (molecular beam epitaxy), VLSI (very large scale integration), and due to the employment of new types of semiconductors and heterostructures. However, the main material, which can be found in any computer or communication system, is still silicon.
A second revolution is born, thanks to the microelectromechanical systems (MEMSs), which are three-dimensional (3D) chips that are able to change information with the environment, and which are produced by the simultaneous miniaturization of electronic and mechanical devices. In contrast to electronic or mechanical components, which can be separately designed, fabricated, and eventually assembled in a remote place, the design of MEMSs and their fabrication is an integral process, which cannot be separated into elementary steps. MEMSs have thus the status of a system, the MEMS revolution is characterized by the miniaturization of systems and not of components.
From its first industrial application in 1979 by Hewlett- Packard (HP) as a micro-machining technique to develop a printer inkjet nozzle enabling thermal inkjet technology, MEMS have traversed log joinery of technological innovations and getting miniaturised along the way to be able to control the auto adjusting screen orientation in our smartphones today. As MEMSs become smaller, require less power and become less expensive they are expected to play an indispensable part in wireless internet of things in home automation.
When it comes to MEMS, micro sensors and micro actuators have taken centre stage. These two MEMS components are housed under the category of transducers, which convert one form of energy to another. The microsensors can be designed to capture various physical or environmental characteristics, including pressure, temperature, acceleration, vibration, chemical species, radiation, inertial forces, magnetic fields, and so forth.
Microactuators, despite their small size, have also demonstrated a variety of useful applications as well as reliable and powerful performance capabilities. Recent applications include “microvalves for control of gas and liquid flows; optical switches and mirrors to redirect or modulate light beans; independently controlled micromirror arrays for displays,” and so much more. In a number of instances, researchers and developers were surprised to find that microactuators performed well at the macroscale level, either meeting or exceeding the performance standards of much larger counterparts.
The development of MEMS was dictated by the need for high-speed data processing in global communication systems, which require rapid reconfiguration of various communication routes. Also, the MEMS advance was boosted by the need for the integration of sensing and monitoring devices in various applications that range from environment monitoring to medical surgery. Therefore, the MEMS chip is often called “smart” since it can sense the chemical, mechanical, physical, electrical, optical, etc. modifications of the environment and can exploit them in order to perform a specific task. The abilities of the MEMS chip to act and decide are expected to generate astonishing applications in electronics, communications, or biology.
MEMS vs. NEMS
While MEMS stands for the micro-electromechanical system, NEMS stands for the nano-electromechanical system. NEMS would be used in Nanotechnology, which is a technology that can manipulate matter at a nanoscale (around the atomic or molecular level). A top-down approach to nanotechnology uses devices that share many similar techniques to MEMS. MEMS and NEMS are sometimes referred to as separate technologies but can be considered as dependent on one another as NEMS technologies are required for NEMS. As an example, a scanning tunnelling-tip microscope (STM), which can detect atoms, is a MEMS device.
As an alternative to quartz components, microelectromechanical system (MEMS) technology has emerged as a primary timing source for automotive applications, such as ADAS and EV power and battery management systems, which require exceptional reliability while handling environmental stressors. Like their quartz counterparts for automotive, MEMS timing components are designed to meet rigorous AEC-Q100 automotive qualification requirements. This industry qualification assures automakers that their timing components, whether quartz or MEMS-based, provide the robustness, reliability and performance demanded by automotive electronic systems.
The Global MEMS market was valued at USD 10.92 billion in 2020 and is expected to reach USD 18.88 billion by 2026, registering a CAGR of 8.71%, during the forecast period of 2021-2026. The increasing popularity of IoT in semiconductors, increasing demand for smart consumer electronics and wearable devices, and growing adoption of automation in industries and homes are some of the significant factors influencing the growth of the MEMS market.
Mayank Vashisht | Sub Editor | ELE Times