Micro-Electro-Mechanical Systems, or MEMS, is a technology that in its most general form can be defined as miniaturized mechanical and electro-mechanical elements (i.e., devices and structures) that are made using the techniques of microfabrication. The critical physical dimensions of MEMS devices can vary from well below one micron on the lower end of the dimensional spectrum, all the way to several millimeters. Likewise, the types of MEMS devices can vary from relatively simple structures having no moving elements, to extremely complex electromechanical systems with multiple moving elements under the control of integrated microelectronics. The one main criterion of MEMS is that there are at least some elements having some sort of mechanical functionality whether or not these elements can move. In other words Microsystems are miniaturized integrated systems in a small package or more specifically, micro-sized components working together as a system and assembled into a package that fits on a pinhead. In the United States, these devices are referred to as microelectromechanical systems or MEMS. European countries referred to such devices as microsystems or MST. These two terms – MEMS and MST – are often used interchangeably. Microsystems are microscopic, integrated, self-aware, stand-alone products that can sense, think, communicate and act. Some systems can do all of these things, plus scavenge for power.

1. MEMS FOR SPACE
By:- Hanuman Dhayal
Branch:-Mechanical [I]
Roll No.:-13EEBME018

2. Content
• Introduction
• Components of MEMS
• Scale of Things: Comparison of MEMS with things you
know
• Materials for MEMS manufacturing
• Fabrication Process
• Manufacturing Technologies
• Manufacturing Approaches

3. Cont.…
• Application
• MEMS space application
• Current Challenges
• Industry Structure
• Future Scope
• References

4. Introduction
• A technology defined as miniaturized mechanical and electro-
mechanical elements (i.e. devices and structures) that are made using
the techniques of microfabrication.
• one main criterion of MEMS is that there are at least some elements
having some sort of mechanical functionality whether or not these
elements can move.
• Microsystems are miniaturized integrated systems in a small package
or more specifically, micro-sized components working together as a
system and assembled into a package that can even fits on a pinhead.

5. Cont.…
• Microsystems are microscopic, integrated, self-aware, stand-alone
products that can sense, think, communicate and act. Some systems
can do all of these things, plus scavenge for power.
• Made up of components
between 1-100 micron
in size

6. Components of MEMS
Microsensors:
• constantly gather data from environment
• pass data to microelectronics for processing
• can monitor mechanical, thermal, biological, chemical
optical, and magnetic readings
Microelectronics:
• data comes from microsensors
• “brain” that receives, processes, and makes decisions
Microactuator:
• acts as trigger to activate external device
• microelectronics will tell microactuator to activate device
Microstructures:
• extremely small structures built onto surface of chip

7. Cont.…
a surface micromachined electro-
statically-actuated micromotor :
MEMS-based microactuator
a surface micromachined
resonator: MEMS microsensor

8. Scale of Things: Comparison of MEMS with
things you know
Three MEMS blood pressure
sensors on a pin head
Smallest microchain of world: The distance
between chain link centers is 50 µm. dia of
a human hair is approx. 70 µm.
500 µm
Gear with height 1780 µm,
PCD=28 µm, tooth thickness=8
µm

9. Materials for MEMS manufacturing
• Silicon
• Polymers
• Metals
• ceramics

10. Fabrication Process
• Deposition
 Physical
 Chemical
• Patterning
• Etching
 Wet
 Dry
Lithography
 Photolithography
 Electron beam lithography
 Ion beam lithography
 X-ray lithography

11. Manufacturing Technologies
• Bulk Micromachining
• Surface Micromachining
• High Aspect Ratio (HAR) silicon Micromachining

12. Manufacturing Approaches
• Top down
• Bottom up

13. Application
• Polymerase Chain Reaction (PCR) microsystems for DNA amplification
and identification, enzyme linked immunosorbent assay (ELISA), biochips
for detection of hazardous chemical and biological agents
• Medicine:-To monitor blood pressure in intravenous lines of patients in
intensive care, To measure intrauterine pressure during birth, To monitors
patient’s blood pressure and respiration, To measure and control the
vacuum level used to remove fluid from the eye, during eye surgery.
• Communications:- RF-MEMS technology, MEMS microphones
• Inertial Sensing:-accelerometers and gyroscopes, crash air-bag deployment
systems in automobiles
• Acceleration sensor in Game player,Digital micromirror device in Projector,
Ink-jet printer head in Printer

14. In the Car

15. MEMS in Space
• MEMS Pressure Sensors
• Microelectromechanical Gyros
• Carbon Nanotube Sensors For Gas Detection
• MEMS Rate Sensor On Cryosat-2
• Solid-State Radiation Monitor
• Mems-Based Xylophone Magnetometer

16. Current Challenges
• Access to Fabrication :-Lack of
i)resources for designing, prototyping, or manufacturing devices
ii)expertise among their staff
• Packaging :- these devices need to be simultaneously in contact with their
environment as well as protected from it.
• Fabrication Knowledge Required :- high level of fabrication knowledge
and practical experience coupled with a significant amount of innovative
engineering skill in order to create and implement successful device
designs

17. Advantages
Main advantages of using MEMS over ordinary large scale machinery.
• Ease of parts alteration, Small size and light weight.
• Higher reliability than their macro scale counterparts.
• Robust for the radiation, vibration and the shock of launch due to small mass.
• Low cost Similar to semiconductor process, MEMS can be mass-produced
with good and stable quality.
• Can be integrated with electronics (system on one chip)
• Speed: Lower thermal time constant , Rapid response times(high frequency)
• Power consumption: low actuation energy ,low heating power

18. Disadvantages
• Due to their size, it is physically impossible for MEMS to
transfer any significant power.
• MEMS are made up of Poly-Si (a brittle material), so they
cannot be loaded with large forces.
• High initial development cost.

19. Industry Structure

20. References
• http://ieeexplore.ieee.org/document/494033/?reload=true
• https://en.wikipedia.org/wiki/Microelectromechanical_systems
• https://www.nasa.gov/centers/ames/research/technology-
onepagers/gas_detection.html
• https://www.jpl.nasa.gov/nmp/st6/TECHNOLOGY/mems.html
• https://www.nasa.gov/centers/glenn/news/AF/2008/Mar08_Sensors_N
R.html
• http://www.memsnet.org/news/
• https://www.mems-exchange.org/MEMS/what-is.html