MEMS devices are within the size range of
1 µm to 1 mm
What MEMS means. MEMS stands for Micro-Electro-Mechanical Systems — devices that combine mechanical elements (beams, membranes, gears, mirrors) with electronics on a single silicon chip, made using the same photolithographic batch processes as ICs. The clue is in the name: the characteristic feature sizes are in the micro range.
The accepted size range. MEMS structures span roughly 1 µm to 1 mm: individual features (a beam thickness, a comb-finger gap) are a few micrometres, while the complete device (a pressure-sensor diaphragm, an accelerometer proof mass, a DMD micromirror array element) reaches up to about a millimetre.
Checking the other ranges.
| Range | What it actually describes |
|---|---|
| 1 pm – 1 nm | atomic dimensions (an atom is ~0.1 nm) — far below any fabricated device |
| 1 nm – 1 µm | the nano regime — NEMS (nano-electro-mechanical systems), nanotubes, thin films |
| 1 mm – 1 cm | macroscopic, conventionally machined components |
| 1 µm – 1 mm | MEMS |
Everyday examples. The accelerometer and gyroscope that rotate your phone's screen, the pressure sensor in a car's airbag and tyre-pressure system, inkjet print heads, digital micromirror devices in projectors, and MEMS microphones — all built by surface or bulk micromachining of silicon.
Why the scale matters. At micrometre dimensions, surface forces (electrostatic attraction, friction, surface tension) dominate over volume forces such as gravity and inertia, which is why MEMS actuators are usually electrostatic comb drives rather than scaled-down motors.
Hence, MEMS devices lie in the size range of 1 µm to 1 mm.
Similar Questions
Given below are two statements :
Statement I : Concentration of acceptor atoms in the region between isolation islands in a monolythic integrated circuit will be much higher then in a p-type substrate.
Statement II : The higher density is provided to prevent the depletion region of the reverse biased isolation to substrate junction from extending into the p+ type material.
In the light of the above statements, choose the most appropriate answer from the options given below :
Arrange the following fabrication steps in order needed to fabricate the IC :
(a) Oxidation (b) Etching (c) Metallization (d) Epitaxial growth
Codes :
Assertion (A) : In a bipolar IC fabrication, the diode isolation is used to isolate one device from the other.
Reason (R) : P+n diode used as isolation diode in IC fabrication.
Select your answer using the codes given below.
Assertion (A) : The epitaxial layer growth possesses the same crystal structure to that of the substrate on which it is grown.
Reason (R) : It can only be of similar conductivity type but possesses different value of resistivity to that of the substrate.
Select your answer using the codes given below.
In an npn diffused junction transistor, the p-type base region is formed on the n-type collector region through the process of :
Assertion (A) : The value of thin film resistor can be changed even after fabrication.
Reason (R) : This is done by means of trimming.
Select your answer using the codes given below.
The evaporation rate from a clean surface is related to the equilibrium vapour pressure Pe of the evaporating species of molecular weight M by an expression :
Czochralski (Cz) method is used instead of using float zone technique to grow Si crystal because it produces :
Czochralski system of crystal growth is a
The thermal oxidation of silicon single crystal producer stacking faults lying on the plane.
Important Questions from Device Technology
Given below are two statements :
Statement I : Concentration of acceptor atoms in the region between isolation islands in a monolythic integrated circuit will be much higher then in a p-type substrate.
Statement II : The higher density is provided to prevent the depletion region of the reverse biased isolation to substrate junction from extending into the p+ type material.
In the light of the above statements, choose the most appropriate answer from the options given below :
Arrange the following fabrication steps in order needed to fabricate the IC :
(a) Oxidation (b) Etching (c) Metallization (d) Epitaxial growth
Codes :
Assertion (A) : In a bipolar IC fabrication, the diode isolation is used to isolate one device from the other.
Reason (R) : P+n diode used as isolation diode in IC fabrication.
Select your answer using the codes given below.
Assertion (A) : The epitaxial layer growth possesses the same crystal structure to that of the substrate on which it is grown.
Reason (R) : It can only be of similar conductivity type but possesses different value of resistivity to that of the substrate.
Select your answer using the codes given below.
In an npn diffused junction transistor, the p-type base region is formed on the n-type collector region through the process of :
