MEMS and NEMS

Microelectromechanical system (MEMS)

MEMS (Microelectromechanical system) is used to integrate with devices and systems that combine mechanical and electrical items. Integrated circuit (IC) batch processing techniques are used to fabricate the MEMS systems and they range from micrometres to millimetres. MEMS systems can control and actuate on the micro-scale and generate effects on the macro scale.

MEMS is called Microsystems Technology (MST) in Europe and Micromachines in Japan. MEMS are fabricated through a micromachining process while silicon and other substrates are manipulated sophisticatedly. Bulk and surface micromachining and high aspect ratio micromachining (HARM) processes are used to remove parts of the silicon or add additional structural layers to form the mechanical and electromechanical components. Therefore, MEMS shows either the mechanical properties of silicon or both electrical and mechanical properties.

Figure 1: Schematic illustration of MEMS

Generally, microsensors, microstructures, microelectronics, and microactuators are integrated into one silicon chip.

Microsensors: - Detect the changes in the system’s environment, such as thermal, mechanical, magnetic, chemical, and electromagnetic information.

Microelectronics: - The detected changes are processed by microelectronics and give the signal to microactuators to react and create a re-change to the environment.

MEMS components are usually very small and microscopic. But MEMS is not just about the mechanical components miniaturization process. Although, MEMS can be identified as a manufacturing process which is used to design and create complex mechanical devices and systems and their electronics. The batch fabrication technique is used for the MEMS manufacturing process. As an example, gears, levers, motors and steam engines are manufactured.

The size of MEMS components is between 1-100 µm and MEMS sensors are generally classified as the range in size 20 µm^-1 to mm.

Nanoelectromechanical systems (NEMS)

Nanoelectromechanical systems are denoted as NEMS. This is the technology that can be used to integrate electrical and mechanical functions in Nanoscale. NEMS are the next logical miniaturization step from the microelectromechanical system (MEMS). NEMS are fabricated using a micromachining process. NEMS are very small and hundreds of NEMS devices can be installed in one space of microdevice that performs the same functions.

NEMS is also integrated with sensors, electronics, actuators, photonics, energy, fluidic, chemistry and biological systems that are enabled by sub-micrometre and engineering precision.

NEMS technology is currently used in low and medium-volume applications.

Figure 2: Aluminum Nitride Piezoelectric NEMS devices using 2-dimensional Electrode Material