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

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

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

4. Smart 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 clothing (material or structure ?)
Goretex®
micro-porous expanded PTFE discovered in 1969 by Bob Gore
~ 14 x 1012 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:

7. Intelligent 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)
composites made at low temp
 can embed additional components
control can decide on novel response

9. Intelligent structures (IS)
embed three elements of the system:
sensors
signal processing and control
actuators

10. Sensors 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)
image from
Non-Destructive Testing of Fibre-Reinforced Plastics Composites

12. OFBG 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 processing
issues with data fusion for large sensor arrays

14. Control proportional integral derivative (PID) advanced systems ...
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 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. Actuators 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

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

19. Intelligent Structures: applications
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. Biomimetics
also known as
bionics
biognosis
synthetic biology

21. Biomimetics
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. Biomimetics “inspiration rather than imitation” Janine Benyus.
“design inspired by nature” BioNIS thematic network 

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

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

25. Gecko tape image from http://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. Biomimetics Lotus effect self-cleaning surfaces
surface of leaf water droplet on leaf
Image from

27. Biomimetics: 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

28. Biomimetics 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
Image from

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

30. Aeroelastic tailoring
Grumman X-29 FSW aircraft 1984 to 1992

31. Hydroelastic tailoring
marine sterngear
propellers
composite twisted rudders for USN DDG51 class destroyers
marine renewable energy (MRE) devices
image from

32. Platelet TechnologyTM
Brinker Technology Platelet TechnologyTM
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 (abalone/mother-of-pearl)
CaCO3 aragonite crystals hexagonal platelets: 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. Nacre
Micrograph from Tomsia et al
Schematic from

35. Chobham 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-fabric pine-cone model
adapts to changing temperatures by opening when warm or shutting tight if cold

37. 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:

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

39. Acknowledgements
Various websites from which images have been extracted