a presentation of self-healing materials.. a major chunk of information is from the presentation of Ian Bond, University Of Bristol

1. Self-Healing Materials SAHIL GUPTA P2008CS1030 RAGHAV PAUL P2008ME1122

3. Approaches to self-healing

4. Microsphere embedment

5. 3D Micro-vascular embedment

6. Electro-hydrodynamics

7. Possible Applications & Future scope

8. Concluding remarks Self Healing Materials

10. to design (never two the same)

11. to implement (removal from service or in-situ repair)

12. to certify & monitor (additional inspection often required) throughout remaining operational life.

13. Sense and respond to damage,restore performance without affecting inherent properties.

14. KEY! - No human intervention required.

15. Provide early means of detection of damage

17. Materials used There are several constituent materials which, when combined function as self healing material system: Healing Agent: Dicyclopentadiene (DCPD) Microcapsule shell:Urea–formaldehyde (UF) (mean 166µm diameter) Chemical Catalyst: Bis(tricyclohexylphosphine) bensylidine ruthenium (IV) Flexiblizer: Heloxy 71, Shell Chemical Company used to improve toughness and crack growth stability. Polymer Matrix:Epoxy Polymer Matrix EPON 828 Fiber Reinforcement: Carbon Fiber (Plain weave fabric constructed with 3K towns)

18. Re-healing capable materials Material could use a system of veins to distribute healing agent intelligently The bio-inspired design delivers healing agent to cracks in a polymer coating via a three-dimensional micro-vascular network embedded in the material. Crack damage is thus healed repeatedly. This can also ensure continuous delivery of healing agents for self-repair from a additional reservoir 3D Microvascular structure embedment

19. Electrohydrodynamics NiSO4 can be electrochemically dispersed into the small voids present in the system. Voltage applied across inner and outer surfaces. Damage causes an increase in current density at the location of the damage Increased current density causes particle coagulation at damage site

20. Shape Memory Alloys Shape memory alloys such as Nitinol (a Nickel-Titanium alloy) exhibit the self healing effect when heated Before heating the material tends to have low yield strength After heating to a certain temperature the material returns to the original state In returning to the original state, large forces can be generated

23. Catalyst, and microsphere ‘clustering’ causes less polymerization

24. Manufacturing of material is very difficult and expensive

25. More research is required before real world applications are exercised