Innovative approach in mems

INNOVATIVE APPROACH IN MICRO-ELECTROMECHANICAL

SYSTEM (MEMS)

Presented By – Dibyaranjan SahooGuided By – Abinash Samanta

Outline

History MEMS Introduction Sensor and its type Fabrication MEMS Manufacturing Technology Applications Conclusion References

2INNOVATIVE APPROACH IN MICRO-ELECTROMECHANICAL SYSTEM

(MEMS)

History

1947 – Transistor Developed 1954 - Silicon & Germanium have piezoelectric effect invented by C S

Smith 1958 - J K Killey produce first IC 1967 - First mems Device “ RGT ”( ) 1971 – INTEL 4004 , First Microprocessor Developed using Mems 1979 – Micro machine Ink Nozzle is used in Printer 1988 – First Micro Motor is developed 1993 – Accelerometer & Digital Mirror device is developed

INNOVATIVE APPROACH IN MICRO-ELECTROMECHANICAL SYSTEM (MEMS) 3

What is MEMS?

MEMS or Micro-Electro Mechanical System is a technique of combining Electrical and Mechanical components together on a chip, to produce a system of miniature dimensions.

MEMS is the integration of a number of micro-components on a single chip which allows the microsystem to both sense and control the environment.

The components are integrated on a single chip using micro fabrication technologies.

4INNOVATIVE APPROACH IN MICRO-ELECTROMECHANICAL SYSTEM (MEMS

What is a Sensor?

A device used to measure a physical quantity(such as temperature) and convert it into an electronic signal of some kind(e.g. a voltage), without modifying the environment.

What can be sensed?

Commonly sensed parameters are: Pressure Temperature Flow rate Radiation Chemicals

N

S

EW 2 Axis Magnetic Sensor

2 Axis Accelerometer

Light Intensity Sensor

Humidity Sensor

Pressure Sensor

Temperature Sensor


But why MEMS for sensors?

Smaller in size Have lower power consumption More sensitive to input variations Cheaper due to mass production Less invasive than larger devices


Type of Sensors

MechanicalSensors

•Strain Gauges•Accelerometers•Pressure Sensors•Microphones•Gyroscopes(Rotation Rate)

OpticalSensors

•Direct Sensors (Light Electronic Signal)•Indirect Sensors (Light Intermediate Energy Electronic Signal)•Biological Light Sensors

ThermalSensors

•Thermo mechanical (Dimension)•Thermo Resistive (Resistance)•Acoustic (Sound)•Biological

Chemical & Biological Sensors

•Electronic Nose•Electronic Tongue


Fabrication

Materials used are: Silicon Polymers Metals Ceramics

Basic Process

Deposition Patterning Etching


Basic Process of Fabrication

Deposition Deposition that happen because of a chemical reaction or physical reaction.

Patterning The pattern is transfer to a photosensitive material by selective exposure to a radiation

source such as light. If the resist is placed in a developer solution after selective exposure to a light source, it will etch away.

Etching Etching is the process of using strong acid to cut into the unprotected parts of a metal

surface to create a design in. There are two classes of etching processes:

Wet Etching Dry Etching.


MEMS Manufacturing Technology

Bulk Micromachining

Surface Micromachining

High Aspect Ratio (HAR) Silicon Micromachining



This technique involves the selective removal of the substrate material in order to realize miniaturized mechanical components.

A widely used bulk micromachining technique in MEMS is chemical wet etching, which involves the immersion of a substrate into a solution of reactive chemical that will etch exposed regions of the substrate at very high rates.

Bulk Micromachining

Etched grooves using (a) Anisotropic etchants, (b) Isotropic etchants, (c) Reactive Ion Etching (RIE)



In surface micromachining, the MEMS sensors are formed on top of the wafer using deposited thin film materials.

Surface Micromachining

(a) Spacer layer deposition.(b) Pattering of the spacer layer.(c) Deposition of the microstructure layer.(d) Patterning of desired structure.(e) Stripping of the spacer layer resolves final

structure.



HAR combines aspects of both surface and bulk micromachining to allow for silicon structures with extremely high aspect ratios through thick layers of silicon (hundreds of nanometers, up to hundreds of micrometers).

HAR MEMS technology enables a high degree of immunity to high-frequency, high-amplitude parasitic vibrations.

High Aspect Ratio (HAR) Silicon Micromachining


Applications in Automobile

14

Applications in Medical Science Biocavity leaser : This device distinguishes

cancerous from non cancerous cells thus aiding the surgeons in operations.

Smart Pill : Implanted in the body Automatic drug delivery (on demand)

Sight for the blind : MEMS based array that may be inserted in the retina of a blind person to provide partial sight


Applications in Marine Science

Sensing in marine environment maybe done for various reasons:

Oil exploration and related applications

Global weather predictions

Monitor water quality for any contamination

Measure parameters detrimental to the “health” of structures in the sea ( like oil rigs and ships )

Study of aquatic plants and animals

In military operations 16INNOVATIVE APPROACH IN MICRO-ELECTROMECHANICAL SYSTEM (MEMS

Applications in Electronics

17

Applications in Marine Military Operations

An array of MEMS sensors spread on the ocean floor could detect the presence of enemy submarines.

MEMS sensors (pressure sensors, accelerometers etc.) are being used in anti-torpedo weapons on submarines and ships.

MEMS sensors in torpedoes are responsible forDetonating the torpedo at the right timeHitting the target in a crowded environmentPrevent any premature explosion


CONCLUSION

MEMS promises to be an effective technique of producing sensors of high quality, at lower costs.

Thus we can conclude that the MEMS can create a proactive computing world, connected computing nodes automatically, acquire and act on real-time data about a physical environment, helping to improve lives, promoting a better understanding of the world and enabling people to become more productive.

References

X. Wang, J. Engel, C. Liu, J. Micromech. Microeng. 2003, 13, 628. Christian A. Zorman, Mehran Mehregany, MEMS Design and Fabrication, 2nd Ed. 2,16. Ms. Santoshi Gupta, MEMS and Nanotechnology IJSER, Vol 3, Issue 5,2012 Stephen Beeby, MEMS Mechanical Sensor, PP. 7 Lenz, J., Edelstein, A.S., "Magnetic sensors and their applications." IEEE Sensors J.

2006, 6, 631-649. Sinclair M J 2000 A high force low area MEMS thermal actuator Proc. 7th Intersociety

Conf. on Thermal and Thermomechanical Phenomena (Las Vegas, NV) pp 127–32 R. Ghodssi, P. Lin (2011). MEMS Materials and Processes Handbook. Berlin: Springer. Chang, Floy I. (1995).Gas-phase silicon micromachining with xenon difluoride. 2641.

pp. 117.


Thank You21

Innovative approach in mems

Technology

Transcript of Innovative approach in mems