Smart materials are functional materials that exhibit stimuli-responsive properties, such as shape-memory, self-cleaning, self-healing, and sensing capabilities.

Smart materials are functional materials that exhibit stimuli-responsive properties, such as shape-memory, self-cleaning, self-healing, and sensing capabilities.

1. Smart materialsSmart materials
Intelligent StructuresIntelligent Structures
BiomimeticsBiomimetics
John Summerscales
School of Marine Science and Engineering
University of Plymouth

2. Smart materialsSmart materials
“smart responds to a stimulus
with one predictable action”

3. Smart materialsSmart materials
normal materials have limited responses
smart materials have appropriate responses
... but response is the same every time
.pptx has
additional
video

4. Smart materialsSmart materials
smart materials have appropriate responses
photochromic glass
•darkens in bright light
low melting point wax in a fire sprinkler
•blocks the nozzle until it gets hot
acoustic emission
•sounds emitted under high stress
embedded optical fibres
•broken ends reflect light back
microporous breathable fabrics

5. Waterproof clothingWaterproof clothing
(material or structure ?) (material or structure ?)
Goretex
®
micro-porous expanded PTFE
discovered in 1969 by Bob Gore
~ 14 x 10
12
micropores per m².
each pore is about 700x larger than
a water vapour molecule
water drop is 20,000x larger than a pore

6. Goretex:Goretex:

7. Intelligent structuresIntelligent structures
“the definition of insanity is
doing something over and over again
and expecting
 a
different 
result”
… variously attributed to
Albert Einstein, Benjamin Franklin and Mark Twain
“intelligent responds to a stimulus
with a calculated response
and different possible actions”

8. Intelligent structures (IS)Intelligent structures (IS)
composites made at low temp
 can embed additional components
control can decide on novel response

9. Intelligent structures (IS)Intelligent structures (IS)
embed three elements of the system:
sensorssensors
signal processing and controlsignal processing and control
actuatorsactuators

10. SensorsSensors
strain gauges
microdieletric interdigitated sensors
optical fibres
piezoelectric crystals
shape memory alloys
sensitive semiconductor chip
giant magnetoimpedance (GMI) wires

11. Optical Fibre Bragg Grating (OFBG)Optical Fibre Bragg Grating (OFBG)
Non-Destructive Testing of Fibre-Reinforced Plastics Composites
image from http://en.wikipedia.org/wiki/Image:Fbg.GIF

12. OFBG applicationsOFBG applications
Maltese Falcon superyacht
CFRP 57 m masts with CFRP yards
OFBG report  and  to bridge
West Mill Bridge (Oxfordshire, 2002)
ASSET pultrusions
OFBG/PZT 250 scans/s

13. Signal processingSignal processing
issues with data fusion
for large sensor arrays

14. ControlControl
proportional integral derivative (PID)
proportional:
output = (gain x error) + bias
integral:
output = gain x (error + ∫error w.r.t. time)
derivative:
output = gain x derivative x de/dt
advanced systems ...

15. Advanced controlAdvanced control
proportional integral derivative (PID)
fuzzy logic control (FLC)
sliding mode control
artificial neural networks (ANN)
genetic algorithms (GA)
knowledge-based systems/
artificial intelligence/expert systems

16. ActuatorsActuators
hydraulic, pneumatic and electric
piezoelectric crystals
shape changes when voltage applied
shape memory materials
shape changes at a specific temperature
alloys = SMA .... polymers = SMP
magneto-rheological (MR) fluids
viscosity changes with magnetic field
electro-rheological (ER) fluids
viscosity changes with electric field

17. shape memory alloy
http://sirius.mtm.kuleuven.be/Research/ADAPT/Video/05-11_11-05_1.avi

18. Magneto-rheological (MR) fluidsMagneto-rheological (MR) fluids
Electro-rheological (ER) fluidsElectro-rheological (ER) fluids

19. Intelligent Structures: Intelligent Structures: applicationsapplications
artificial hand
SMA fingers controlled by
nerve (myoelectric) signals
vibration damping
apply electric field to ER fluid
skyscraper windows
acoustic emission warning system
lucky guy survives accident in Riyadh (video)

20. BiomimeticsBiomimetics
also known as
bionics
biognosis
synthetic biology

21. BiomimeticsBiomimetics
the concept of taking ideas from nature to
implement in another technology
Chinese silk cultivation begins c.4000BC
•Colin Thubron, Shadow of the Silk Road, Chatto & Windus, 2006.
Daedalus' wings - early design failures
gathering momentum due to the
ever increasing need for
sympathetic technology

22. BiomimeticsBiomimetics
“inspiration rather than imitation”
Janine Benyus.
 “design inspired by nature”
BioNIS thematic network
 

23. BiomimeticsBiomimetics
Notable innovations
from understanding nature
Velcro
Gecko tape
Lotus effect self-cleaning surfaces
Drag reduction by shark skin
Platelet Technology
TM
for pipe repair
Smart-fabric
ElekTex™
Chobham armour vs nacre

24. BiomimeticsBiomimetics
Velcro
small hooks enable seed-bearing burr
to cling to tiny loops in fabric

25. Gecko tapeGecko tape
image fromimage from
http://www.netcomposites.com/news.asp?3922http://www.netcomposites.com/news.asp?3922
geckos to hang single-toed from sheer walls
and walk along ceilings using fine hairs on feet
University of California - Berkeley created an
array of synthetic micro-fibres
using very high friction
to support loads on smooth surfaces.

26. BiomimeticsBiomimetics
Lotus effect self-cleaning surfaces
surface of leafwater droplet on leaf
Image from http://library.thinkquest.org/27468/e/lotus.htm

27. Biomimetics: Lotus effectBiomimetics: Lotus effect
most efficient self-cleaning plant
= great sacred lotus
(Nelumbo nucifera)
mimicked in paints and
other surface coatings
pipe cleaning in oil refineries (Norway)
Images from
http://library.thinkquest.org/27468/e/lotus.htm
http://www.villalachouette.de/william/lotusv2.gif
http://www.nees.uni-bonn.de/lotus/en/vergleich.html

28. BiomimeticsBiomimetics
drag reduction by shark skin
special alignment and grooved structure
of tooth-like scales embedded in shark skin
decrease drag and thus
greatly increase swimming proficiency
Airbus fuel consumption down 1½%
when “shark skin” coating applied to aircraft
oImage from http://www.pelagic.org/biology/scales.html

29. 30
Biomimetics
http://www.rarebirdphotography.co.ukhttp://www.rarebirdphotography.co.uk
Common Tern Ivory Gull
Squacco Stone Curlew

30. 31
Grumman X-29
FSW aircraft 1984 to 1992
http://www.globalsecurity.org/military/systems/aircraft/x-29.htm
Aeroelastic tailoringAeroelastic tailoring

31. HydroelasticHydroelastic
tailoring tailoring
marine sterngear
propellers
composite
twisted rudders
for USN DDG51
class destroyers
marine renewable
energy (MRE)
devices
image from http://d2n4wb9orp1vta.cloudfront.net/resources/images/cdn/cms/1408-a.jpg

32. Platelet TechnologyPlatelet Technology
TMTM
Brinker Technology Platelet Technology
TM
discrete particles released into pipe flow
when particles encounter modified flow
at a leak, fluid forces entrain them into
the leak and hold them against the pipe wall
seals and marks the position
of the leak for subsequent detection.
YouTube videos:
animation the technology Yorkshire Water Scottish Water

33. Nacre Nacre (abalone/mother-of-pearl)(abalone/mother-of-pearl)
• CaCO
3 aragonite crystals
hexagonal platelets: 10-20 µm x 0.5 µm thick
arranged in a continuous parallel lamina.
• layers separated by sheets of organic matrix
composed of elastic biopolymers
(such as chitin, lustrin and silk-like proteins).
• brittle platelets and thin elastic biopolymers
makes the material strong and resilient
due to adhesion by the "brickwork“
arrangement of the platelets
which inhibits transverse crack propagation.

34. NacreNacre
Micrograph from Tomsia et al http://www.physorg.com/news10408.html
Schematic from http://en.wikipedia.org/wiki/Mother_of_pearl

35. Chobham armourChobham armour
an arrangement of metal plates, ceramic
blocks, aramid fabrics
and open space ?
rounds get through the outer layer
ceramic material absorbs
heat and impact energy
aramid fabric catches debris
hot gases or metal pieces
spread around empty air pockets.

36. Smart-fabricSmart-fabric
pine-cone model
adapts to changing
temperatures
by opening when warm
or shutting tight if cold

37. ElekTex™ElekTex™
looks and feels like a fabric
capable of electronic x-y-z sensing
fold it, scrunch it or wrap it
lightweight, durable, flexible
cost competitive
cloth keyboards and keypads
 details: http://www.electrotextiles.com

38. SummarySummary
smart materials
same response for same stimulus
intelligent structures
sensor > control > actuator
adaptive response for same stimulus
biomimetics
nature as inspiration for innovative design

39. AcknowledgementsAcknowledgements
Various websites from which
images have been extracted