Transcript Slide # 1 Project topics

Project topics
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List of projects
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Automotive accelerometer (ONER)
Explosive detection systems
Mass flow and pressure sensors/controllers (WILSON)
Cooled and Uncooled IR sensors (OMAR)
Nanoscale bio-sensors for pathogen detection (DANIELS)
MEMS gyroscopes for navigation (ASIF)
RFID based temperature and humidity sensors (SULTANA)
Strain sensors for prognostics in airplanes and bridges (PATEL)
Volatile organic compound sensors (DULAIMY)
Automotive O2 and NOx sensors (DIWAN)
MEMS/NEMS sensors for pathogen and toxic gases (SHETU)
Graphene based chemical sensors (UDDIN)
MEMS SENSORS based Photoacoustic spectroscopy
(TALUKDAR)
Slide # 1
Linear Optical sensors II
• The PSPDs can be one or two dimensional to
track either unidirectional or planar
movements.
• Unlike CCDs, which consist of discrete
photodiodes, PSD is uniform and non-discrete
• Typical applications of this type of sensors is in
detecting small displacements and on-line
measurement of height, such as, PC board
inspection, level control, etc.
• Also, to determine presence of objects i.e.
hand under tap, or the uniformity of rotating
objects such as medicine caps, bottles, etc.
• The equivalent circuit shown has distributed
capacitance and resistance, so the time
constant is dependent on the position of the
beam
• Typical response time is 1-2 s
• Spectral response is 320 – 11000 nm typically
Slide # 2
Optical sensors: PSPD
Slide # 3
Optical sensors: PSPD problem
Calculate the minimum displacement of a microcantilever that can be sensed if the
measurement uncertainly of the PSPD is 0.5 um. Given that the microcantilever is
positioned 10 cm away from the PSPD and the focal length of the lens for the PSPD is 2
mm. The angle between the incident and reflected beam is 30º.What can you do to improve
the deflection sensitivity of the microcantilever?
Slide # 4
Ultrasonic sensor
Slide # 5
Ultrasonic sensor
Slide # 6
Operating principles
Input ac voltage generates ultrasonic
sound by periodically displacing the
piezo-ceramic element.
On the detector side the ultrasonic wave
would periodically oscillate the piezotransducer generating a small ac voltage
that can be amplified.
Slide # 7
Velocity sensor
Specifications for electromagnetic velocity sensor
Velocity sensors can utilize the same principles of displacement sensor, and produce a
response as a function of time.
A typical velocity sensor, in a fixed direction can be based on a design similar to the LVDT.
In this case, a permanent magnet can be attached to the moving part which will induce a
differential voltage at the output proportional to the speed of the permanent magnet. Note
that unlike LVDT, a constant voltage is produced only when there is a constant movement.
Slide # 8