1. Self-Healing Plastic
Anisah Kabli
ECE 507
Fall 2012

2. Agenda Defining “Self-Healing”? Structure of Plastic
Self-Healing Process
First uses of Self-Healing Plastics
Self-Healing Plastics Today
Benefits of Self-Healing Plastics
The Future of Plastic

3. What makes something self-healing?
Ability to repair damage caused by mechanical usage over time. 
Healing process occurs without human intervention

4. In Nature Rubber Tree Liana Plant Mussels Releases a type of latex
Rubber tapping
 Liana Plant
Base tissue cells expand
Mussels
Heals bonding material

5. Chemical Structure of Plastic
Typically polymers derived from petrochemicals
Polymers are chains of  repeating atoms.
Two parts:
The Backbone: main "path" linking repeat units together.
Side Chains: hang off backbone
Allow the customization of plastics.
The creation of polymers is called polymerization

6. The Self-healing Process
3 step process:
Triggering after damage
Transport of materials 
Chemical repair process
Requires an external stimulus to initiate healing
Energy is introduced into the system to allow repolymerization to take place.
very similar to that of a biological response.
1- or actuation, which happens almost immediately after damage is sustained

7. First Uses of Self-Healing Plastics
2005 – Nissan
Nissan “Scratch Guard” 
Polymer capsules & chitosan 
Only repairs once
2008 – Automatic Materials of Champaign, IL
Protective coatings against rust
Polymer capsules and catalyst
January 2012 – Nissan
Self-Healing iPhone Case- Scratch Shield paint
Clear paint that repairs scratches on painted car surfaces, 
siloxane, a polymer that Braun likens to bathroom caulk
Immersed scratched steel plate in salt water for five days. The metal covered by the new coating was protected against rust, while scratches in the conventional coating allowed significant rusting
restoring mechanical properties to walls so that they won’t crumble or to airplane wings so that they won’t fracture. 
The paint is the same that is featured on numerous Nissan and Infiniti automobiles throughout the world. When damage occurs to the coating, the chemical structure is able to react to change back to its original shape and fill the gap, thus “healing” the blemish. 

8. Self-healing Plastics Today
March University of Southern Mississippi
Bleeding Plastic
Release warning red dye
Heals with sunlight, artificial light, pH or temperature changes
Able to repeatedly heal itself
Environmentally Friendly - water-based polymers

9. Self-Healing Plastic Today
November Stanford University
Plastic “Skin”
Polymer mixed with nickel.
Polymer: Weak bonds. Nickel: Conductivity
Nickel creates an electric current
Resistance determines shape of skin and pressure
allows the molecules to easily break apart
The conductivity from the metal then helps the bonds rearrange themselves and, because of their flexibility, restore the original structure within 30 minutes
Bending, flexing, or otherwise warping the material changes the distance between the nickel particles, altering the material's resistance to the current. That electrical resistance can be measured to determine the shape of the skin and any pressure being exerted on it.

10. Benefits Save Money lower production costs Reusability
longer part lifetime,
reduction of inefficiency and material failure.
Reusability
minimize upkeep and repair
saving consumers money and reducing waste
Ex: Sheathe electronics , nail polish, cars
Once many plastics get scratched or cracked, repairs can be difficult or impossible. 

11. Benefits Improve Safety Medical Uses
Bleeding material act as warning system
flag damage on aircraft structures
Cracks in bridges,
Failings in battlefield weapon systems
Medical Uses
Restore sense of touch to prosthetics

12. Future Self-healing plastics withstand high temperatures
Make the self-healing skin elastic
Flexible but not stretchable
Terminator?

13. Thanks!
Questions?

14. References