Recent advances in micro- and bio- electromechanical system architectures for energy efficient chemiresistors

The recent evolution of microelectromechanical systems (MEMSs) presents a more mature technology that expands from pure research towards multidisciplinary nanoelectromechanical systems (NEMS) research. The smaller size of NEMS makes them multifunctional, fast, energy-saving, and sensitive to any external stimuli. The extreme sensitivity of these NEMS opens new avenues to the various industrial sector of applications in biosensing, gas sensing, and medical implants which won't be possible with traditional MEMS counterparts. Most of the resistive-gas sensors are more popular than others but their elevated working temperatures consume more energy and limit their real-world applications. Various self-heating, embedded MEMS microheaters, and materials have been explored to improve the sensing performance. Thus, there is an urgent need of the hour to review the associated manufacturing techniques and evolution of MEMS fabrication for energy-saving gas sensors and new developments in this area. We overview the various manufacturing process and developments in MEMS/NEMS for gas sensor applications, and their historical perspectives, and provide future guidelines to meet the existing challenges for real-world gas sensing applications.