MEMS TECHNOLOGY
WHAT IS MEMS?
MEMS stands for Micro-ElectroMechanical Systems. They use the acronym MEMS in the US. In Europe, they also call it a micro-systems technology (MST), and in Japan as micro-machine. The former part of the name tells us about the size of it, and the latter part refers to the part used. Their size may vary from 1mm to 1um that are thinner than a strand of hair. The production is like integrated circuits using micro-fabrication methods. MEMS comprises of sensors and actuators in microscopic size combined on a single silicon chip.
THE PROCESS
1. CAD enables us to create designs, and they do the modelling and simulation for the design.
2. The starting silicon wafer substrate goes through a repetitive micro-fabrication process which involves:
· Material deposition using fast ions, chemical vapor, evaporation in a vacuum, oxidation.
· Transfer of pattern through lithography.
· Material etching using deep reactive iron, wet chemical, or dry ion.
3. To end the process, they do the wafer dicing by laser or diamond cutting or plasma etching and wire bonding to make it interactive. The last steps are encapsulation and packaging.
THE NEED
The concept of MEMS is to make a miniature version of macroscopic things with added advantages. For example, there was a time when devices like ball and tube were used in cars as airbags. They were placed in the vehicle’s front, attached with separate electronics near the bag. The conventional airbags that integrated the accelerometer (mechanical) and the electronics into a single chip that can fit inside the steering column replaces the old model. MEMS brought us the comfort that we need through miniaturization at low costs with high accuracy.
THE ADVANTAGES
The sensors are highly sensitive. They can be easily modified or integrated into other systems. They are very small in mass, size and volume. It needs very low power to function. Low cost when the production quantity is very large. Scalable, which means we can try to even bring the mechanisms that are not achievable at the macroscopic level.
THE ONLY DISADVANTAGE
There is only one disadvantage of MEMS. The research and development, testing, fabrication, and assembling cost is very high for lower quantities. So, it is not recommended for small scale production as it is expensive.
THE APPLICATIONS
We commonly use MEMS in numerous sensors such as accelerometers, pressure sensors, gyroscopes, and magnetic field sensors. Their sensors have a number of applications in the automotive, electronics, communication, defence, and medical industries. Airbags in cars, Inkjet printers, projection displays, fibre-optic network components, miniature analytics instruments, pacemakers, mass data storage systems, aircraft controls are the popularly used applications of MEMS.
THE HISTORY
The Germanium transistor invented in 1948 by William Shockley emerged as the first product of MEMS. After that, they invented the first IC and pressure sensors in the 1950s century. The invention of micro-processors and Thermal Inkjet Technology introduced by HP that uses fine-tip nozzles for printing ink are the finest example of MEMS.
THE PRESENT
Today, you are reading this blog as you are using one of the smart products of MEMS. We have various other subsets of MEMS such as BioMEMS, RF-MEMS, and MOEMS. BioMEMS brought sound through hearing aids, sight through retinal implants, and control heartbeats through pacemakers. MOEMS devices are trying to bring the trend to the fast all-optical telecommunication networks. RF-MEMS found in antennae, GPS, and is constantly trying to make smaller and energy-efficient devices for making the world smarter.
THE FUTURE
To create a smart world, to add the word smart to existing things, MEMS plays a major role. The AI paired up with sensor fusion would make the dreams of scientists to realize by astonishing the masses. There would be a time when the virtual and real world would go in close connection because of MEMS technology.