8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 1/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 2/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 3/14

MEMS material selection

• Materials selection is essential for ecientdesign of microelectromechanicalsystems(MEMS).

• For MEMS designers, one of the key jobs forachieving the high level of reliability, lownit cost and o!timal fnction !erformanceof microelectromechanical devices is tocareflly choose materials from a limitedset.

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 4/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 5/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 6/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 7/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 8/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 9/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 10/14

Capacitive micromachined ultrasonic transducers (CMUT) is a relatively

new concept in the field of ultrasonic transducers. Most of the commercial

ultrasonic transducers today are based on piezoelectricity.

CMUTs are the transducers where the energy transduction is due to change in

capacitance. CMUTs are constructed on silicon using micromachining techniue.

 ! cavity is formed in a silicon substrate" and a thin layer suspended on the top

of the cavity serves as a membrane  on which a metallized layer acts anelectrode" together with the silicon substrate which serves as a bottom

electrode.

#f an !C signal is applied across the biased electrodes" the vibrating membrane

 will produce ultrasonic waves in the medium of interest. #n this way it wor$s as

a transmitter .

 %n the other hand" if ultrasonic waves are applied on the membrance of biased

CMUT" it will generate alternating signal as the capacitance of the CMUT is

varied. #n this way" it wor$s as a receiver of ultrasonic waves

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 11/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 12/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 13/14

8/17/2019 Mems Material Selection

http://slidepdf.com/reader/full/mems-material-selection 14/14