Transcript Department of Optical Engineering Zhejiang University

Advanced Sensor Technology
Predecessor：Modern Sensors
Jun. QIAN
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Email:
[email protected]
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Tel:
0571-88206516-215/13505815872/ 636278
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Homepage：
http://mypage.zju.edu.cn/qianjun
Department of Optical Engineering
Zhejiang University
Address of my office:
正校门
Our center
紫金港东五楼 光及电磁波研究中心
浙江大学光电信息系
Department of Optical Engineering
Zhejiang University
What in this course……
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Extend your knowledge in optics and
electronics to a realm of application
Case Study: exemplary modern
sensors
A little bit of Entrepreneurship
education
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Zhejiang University
What are we going to cover?
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Human/Animal Sensors
Sensor Performance Characteristics
Strain Gauge Basics
Capacitive Sensors and Accelerometer (ADXL50)
Piezoelectric / Pressure Sensors
Thermometers/Flow Sensors
Radiation Sensors; IR Sensors
Inductive and Magnetic Sensors (Hard Disk read-write
head)
Chemical Sensors
Gyroscopes
Lectures on Special Topics, Class discussion
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A look at modern sensors
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A look at modern sensors
Top prosthetic limb….
Mind controlled artificial arm
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A look at modern sensors
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Zhejiang University
Electronic Nose
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What can modern sensors
do?
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Detect 2,4,6-trichloroanisole
(TCA) in wine aroma at partper-trillion levels (10-12) in
seconds (Znose by
Electronic Sensor
Technology)
Aromatic compounds in wine
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Electronic Nose
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A vapor analysis system for
homeland security after 9-11
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Detect suspicious gases
Olfactory image
Chemical fingerprints
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Electronic Nose
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How does the Nose look like?
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Sensor head - Big size
More work needs to be done for it to be deployed in a
robot
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Power consumption
Channel number/flexibility
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Accelerometers
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What can modern sensors
do?
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Miniature Accelerometer,
Coloumbia Research Lab
Detect linear acceleration with
high precision for industrial
and military applications
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Zhejiang University
Industry’s Smallest Accelerometer
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Previous Size: 4 x 4 x 1.45 mm3
Manufacture: Analog Device
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ADXL32x family of iMEMS (integrated
micro electro mechanical system)
accelerometers
Present package
2 x 2 x 0.9 mm3
Operating condition:
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power supplies 2.7 V
consume only 450 μA
can be power-cycled for even greater
battery life
The typical noise floor is 200 μg per
rtHz, allowing small tilt changes to be
sensed using the narrow bandwidths
(<10 Hz) typical of human motion
Today
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Zhejiang University
Pyroelectric Infrared Radial Sensor
Product Description
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Model: D203S
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Encapsulation Type: TO-5
Window Size: 4× 3 mm2
Spectral Response: 5-14μm
Output Signal [Vp-p]: ≥3300mV
Sensitivity: ≥3100 V/W
Detectivity (D*): 1. 4 × 108 cmHz1/2/W
Noise [Vp-p]: <70mV
Supply Voltage: 3-15V
Operating Temp: -30-70º C
Application:
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(m)
security systems, burglar alarms,
visitor acknowledgement,
light switch control and intellectualized toy, etc.
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Introduction
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What can modern sensors do?
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Detect brain wave to control computer mouse
(2006)…..
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Using an optical method：
Diffused Optical Tomography (DOT)
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Fiber Optical Sensors
Multi-points
Quasi-distributed
Distributed
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Introduction
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Modern Sensors are
penetrating into our life:
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Medical: Angioplasty,
Infusion Pumps, Blood
Pressure, Kidney Dialysis,
Respiratory
Automotive: Tire Pressure,
MAP, Fuel and Engine
Control Systems,
Barometric
Industrial: Portable Gauges,
Manometers, Altitude
Measurements, Barometry,
Water Depth
Consumer: iphone,
ipad,…ieverything
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Major Industry Players
Analog Devices
Columbia Research Labs
Capacitec
EG&G ICSensors
Endevco
Humphrey
Kistler Instruments
Lucas Novasensor
MTI Instruments Inc.
PCB Piezotronic
Quantum Research Group
Raytek
Sensors Magazine
Silicon Designs
Strain Measurement Devices
Summit Instruments
Thermometrics
Vishay Intertechnology
Yellow Springs Instruments
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Sensor: A Definition
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A sensor is a device that receives a stimulus and
responds with an electrical signal. (maybe
optical in near future)
The term stimulus :
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The stimulus is the quantity, property, or condition
that is sensed and converted into electrical signal.
The purpose of a sensor is to respond to some
kind of an input physical property (stimulus) and
to convert it into an electrical signal which is
compatible with electronic circuits.
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We may say that a sensor is a translator of a
generally (non)-electrical value into an electrical value.
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Example: LevelElectrical signal
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The information is perceived by the sensor, which consists of two
main parts: the sight tube on the tank and the operator’s eye, which
generates an electric response in the optic nerve.
The sight tube by itself is not a sensor, and in this particular control
system, the eye is not a sensor either.
Only the combination of these two components makes a narrowpurpose sensor (detector), which is selectively sensitive to the fluid
level.
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Biological sensors – an introduction
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Physical limits to the measurement of certain
signal
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Temperature fluctuation in finite objects
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Audio background noise limits hearing capability
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Heat capacity or mass
Air speed/turbulence
Limited by environmental disturbance
Broadband audio noise in jungle
Light detection
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Number of photons
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Nocturnal animals’ vision is limited by scarcity of photons
Flicker of starlight
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Biological sensors – an introduction
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Natural evolutionary process in nature
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A remarkable efficient filter (adaptation)
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Some high-performance examples
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Chemical sensing of pheromones in moths
Ultrasound sensing in bats (predators) and moths (prey)
Vision in predators: cats, birds
Low-performance
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Tilt sensing in humans
Tactile sensing
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Human Sensory Capabilities
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System issues
Signal conditioning
 Wiring
 Time response and hysteresis
 Packaging
 Software/hardware tradeoffs
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Human Sensors: Mechanoreceptors
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Experiment
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Rate of adaptation
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Notice how your fingertip sense location, roughness,
thickness and temperature
The rate at which the mechanoreceptor pulse rate
returns to normal after a change in stimulus
Sensors with adaptation do not provide info
about static signals- only about changing signals
A time-vary contact force on the tactile sensors
allow the sensing static quantity-roughness
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Purpose to Study Mechanoreceptors
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Ultimate goal for you: replicate or even
improve the system in a robot
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Zhejiang University
Human Sensors: Mechanoreceptors
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No single type of mechanoreceptor can
accomplish all the functions!
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Extremely difficult to replicate due to
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Multi-layered
Multi-structured
Various response rate
Channel numbers/density
Complex topology
Leading to study of tactile sensor array
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Resistive touch-screen
Capacitive touch-screen
Optical tactile sensor/skin
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Mechanoreceptors - category
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The mechanoreceptors in your skin maybe
separated into distinct categories
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Fast adaptation: <0.1sec
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Pacinian Corpuscles
Moderate adaptation: 1 sec
Meissner’s corpuscles
 Hair follicle receptors
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Slow adaptation: 10-100 sec
Ruffini endings
 Merkel’s cells
 Tactile disks
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Adaptation Curves for Sensory Receptors
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Fast Adaptation
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Pacinian corpuscles
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Named for Filippo Pacini, a 19th Century Italian
anatomist who dedicated his career to microscopic
research,
Somatosensory receptors of hands and feet
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Responds to
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Detect character as expressed by a firm, confident
handshake, an indecisive loose grip, or an over-zealous
bone-crusher
pressure,
any mechanical stimulus that causes deformation of
corpuscle surrounding the single afferent nerve fiber
Pacinian corpuscles can detect vibrations and touch
in terms of frequency, duration, and intensity
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Pacinian corpuscles
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These corpuscles exist within muscles, joints,
and subcutaneous tissues throughout the
body.
The pacinian corpuscle consists of a single
nerve fiber, the terminal region of which is
enclosed in a multi-laminated connective
tissue capsule.
The nerve is myelinated (Having a myelin
sheath) except for the terminal region within
the capsule, which is nonmyelinated
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Moderate Adaptation
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Meissner’s corpuscle
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egg-shaped receptors
consisting of a mass of
intertwined fibers.
located on hairless
skin, between the
dermis and epidermis
that inform the brain
exactly where the skin
is touched.
Meissner's corpuscles
are concentrated in
the fingertips and
palms, lips, and
tongue
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Topology: Meissner’s corpuscles
Most of these cells are
contacted by one terminal
branch of three to five axons
that end in the dome
• Sensor distribution
• Signal grouping
• Resolution
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Adaptation to stimulus
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The nerve terminal within the
Meissner’s corpuscle is sensitive
to mechanical compression,
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which causes it to depolarize.
This depolarization (the generator
potential) increases to a maximum
and then returns to the resting
potential even though the mechanical
stimulus is still applied.
Such a response is referred to as
phasic.
The process by which the magnitude
of the generator potential decreases,
even when the stimulus is maintained,
is called adaptation.
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Slow Adaptation
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Ruffini corpuscles
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1mm fusiform (spindly)
structure with a thin capsule
oriented parallel to the surface
of the skin
have bundles of collagen
fibers coursing through them
which are penetrated by the
axons of the afferent nerves
sheathed by connective tissue
and contain interlaced
networks of nerve fibers.
detect temperature and
pressure
Ruffini's endings are also
found in the joints, where they
signal how far the joint has
rotated.
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Your Mechanoreceptors
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Probing your hand with a toothpick, try to
locate the most sensitive regions
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the most sensitive mechanoreceptors are located
in the fingertips, where skin indentations as small
as 6 microns are detected
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How are your sensors distributed?
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Output Signal of mechanoreceptors
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In the form of a
stream of voltage
pulses
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Amplitude of
signal  pulse
density
Digital rather
than analog
Analogous to
TTL pulses
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Tactile Sensors: Our effort
1996, MEMS capacitive
2008, Sensor Skin: 16 sensors/cm2 ( as
oppose to 1500 in human fingertip),
organic FET made of carbon chains to
create a large, flexible, potentially ultralow cost pressure-sensor
array Engineering
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Zhejiang University
Tactile sensor array on wafer
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Flexible tactile sensor array
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Human-Computer interface
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Virtual Reality glove
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controls remotely a
robot's movements
through her own and
by
seeing,
 hearing –
 even feeling –
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the environment it
works in
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Optical tactile sensor
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Mechanisms: total internal reflection,
surface plasmon resonance, …
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Human Sensory System : Auditory System
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How it works?
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Sound wave pressure deflects
eardrum, and the structures
attached to it
Middle ear: vibration transfer &
attenuation
Inner ear:
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an acoustic spectrum
analyzer (20-20kHz),
individual mechanoreceptors
configured for detection of
particular audio frequencies
One effect of the shape of the
spiral diaphragm is that the
resonant frequency is a
function of position along the
spiral.
any particular acoustic signal
frequency will produce a
mechanical oscillation in the
inner ear at a particular
physical location.
Implanted bionic ear
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Human Sensory System : Smell Sensing
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In the upper nasal cavity
the mucous membrane is
yellow and termed the
olfactory membrane.
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It contains 100 million bipolar
neurons called olfactory cells.
They contain hairs or
olfactory cilia.
The olfactory cells are smell
receptors. They work as
telereceptors,
The olfactory tract then
transmits the olfactory
signals to the olfactory cortex
at the surface of the temporal
lobe.
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Human Sensory System : Visual System
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An “auto-focusing” lens
A photosensitive region
filled with several
different types of
photoreceptor cells
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Different shapes of the
photoreceptor cells serve
to offer sensitivity to
different colors of light
Locations are highly
specialized to optimize
absorptivity
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Pathway from retina to brain, blind spot
Wiring of our sensors
The human eye has a nerve
bundle connecting eye to brain:
• It runs from all of the
photoreceptors to the nervous
system positioned on the back
surface of the eye.
• This location does not have any
photoreceptors, and so there is a
'blind spot' in human vision. Have
you ever noticed it?
Future Tasks:
Head-mount 3D visual game set
3D HDTV 1) wearing glasses , 2) viewing angle,…
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Implanted E-retina
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Summary
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All of these has served to indicate
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Sensing hardware has been the result of evolutionary
development
how a set of sensing hardware can be highly
optimized,
operate in spite of some design problems.
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The mechanoreceptors have adapted to achieve excellent
use of the hands,
The hearing system has developed excellent capabilities for
resolving events in the frequency and time domain,
The vision system uses some sophisticated image
processing to overcome the positioning of the connection of
the optic nerve.
Department of Optical Engineering
Zhejiang University