27-01-2011, 03:33 PM
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Anshul Sharma
D. Vishal
Kamalendu Ghosh
Suddho S. Mukherjee
Yogesh Narnaware
Outline
Introduction
Manufacturing Processes
Materials used
Features of MEMs
Applications: Transportation, automobiles etc.
Advantages and Disadvantages
MEMs in future
Conclusion
Introduction
MEMs can be defined as a combination of microsensors and/or microactuators and electronic devices on a single chip.
These devices involving mechanical and electrical parts capable of acting on and sensing their environment.
sensors are a crucial component in automotive electronics, medical equipment, hard disk drives, computer peripherals,wireless devices and smart portable electronics such as cell phones and PDAs.
MEMS
Micro Electrical Mechanical Systems
Practice of making and combining miniaturized mechanical and electrical components
“Micromachines” in Japan
“Microsystems Technology” in Europe
Microelectronic integrated circuits can be thought of as the "brains" of a system and MEMS augments this decision-making capability with "eyes" and "arms", to allow microsystems to sense and control the environment.
Sensors gather information from the environment through measuring mechanical, thermal, biological, chemical, optical, and magnetic phenomena.
The electronics then process the information derived from the sensors and through some decision making capability direct the actuators to respond by moving, positioning, regulating, pumping, and filtering, thereby controlling the environment for some desired outcome or purpose.
Materials for MEMs
Silicon, glass, ceramics, polymers, and compound
Group III and V elements,
Metals including titanium and tungsten.
Glass and fused quartz substrates,
Silicon carbide and diamond
Gallium Arsenide and other Group III-V semiconductors
Polymers
Shape memory alloys
Actuators
MEMS often involves movable parts, making them microactuators. They can be vibrating, translating, rotating, etc., they all need a mechanical energy to move.
the commonly used technics to get a movement from an object are: Thermal, Electrostatic, Magnetic, Piezoelectric and using Shape-Memory Alloys.
MEMS Applications: Transportation
Roads would be covered with millions of MEMS sensors. The sensors would act as a blanket of information, gathering and transmitting data about road conditions.
Development of windshields with automatic glare resistance.
Detection of ice on roadways.
Send information to vehicles equipped with Global Positioning Devices, informing the on-board computer of road hazards, accidents, and traffic.
Determination of SMS and TMS and other traffic parameters
SMART PAVEMENTS
Microsensors can be embedded in appropriate locations.
The system consists of a retrofitted instrumented asphalt core which is bonded into the pavement structure.
The core contains all information regarding temperature difference, deformations of the pavement.
These microsensors are called “smart aggregates”
MEMS Applications: Wireless
. With the advent of new technology combined with the demand for more bandwidth and increased mobility, wireless applications are spreading to new markets –
from radar-equipped passenger vehicles to biomedical devices that, when injected or inserted, send data to a receiver outside the body.
As the wireless device market grows, so will the semiconductor products that support it.
Other Applications
Inkjet Printers
Accelerometers
MEMS gyroscopes
Pressure sensors
Bio-MEMs
Optical Switching
MEMS Features
Low interference with environment
Accurate, Compact, Shock resistant
Inexpensive - based on IC batch fabrication
Use in previously unfeasible domains
Redundancy
Large sampling size, greater data certainty
Advantages
Low cost (can even be made “disposable”)
They are useful in the field of defense of a nation
Will work for many machine health applications
Onboard signal conditioning. No charge amplifiers required.
Disadvantages
Performance still below that of more expensive sensors
May not be available in industrial hardened packages
It is Application specific .
MEMS in Future
One application still being developed is “smart dust” where MEMS sensors will be deployed in the air to measure pollution.
“smart roads” where MEMS devices would be laid out as a blanket on the roadbed to measure physical conditions and traffic and report the information to geo-positioning systems mounted in cars.
A lot of research into new uses for MEMS is based on military and aerospace applications.
Other innovative applications include MEMS devices are also being used in optical networks and wireless communications.
