In this PPT you know about the SELF HEALING technology in spacecrafts This technology is still under research in NASA. This technology can be also implement on Aircrafts.So it is very simple concept it includes some basic knowledge about Composites materials and its properties.

1. Presented by
YASHWANTH S and SANTOSH
NITTE MEENAKSHI INSTITUTE OF TECHNOLOGY
BANGALORE
Venue:
M V JAYARAMAN COLLEGE OF ENGINEERING, Bangalore
Wednesday, 14th October 2014

2. OVERVIEW
Introduction.
Self Healing Technology.
Why It Is Necessary?
Procedure.
Materials used.
Types of Self healing.
Ways of healing.
Advantages and limitations.
Conclusion.
Literature views.

3. INTRODUCTION.
 When you cut yourself, it's amazing to watch how
quickly your body acts to mend the wound.
 Immediately, your body works to pull the skin around
the cut back together.
 Immediately our body respond to self-healing power.
 Here also a similar system, but replacing blood with
resin and veins with tiny glass tubes, to fill in cracks
or small holes in satellite skin.
 Scientists are now developing a new type of composite
material that will give those same self-healing
qualities to SPACECRAFTS.

4. Self Healing Technology.
Self- healing is the ability to repair damage in an
automatic and specific fashion without manual
intervention. The ability of a material to be able
to heal damages automatically and
autonomously is called SELF HEALING property.
self healing material can close the damage within
their structure by restoring and maintaining its
original mechanical properties.

5. Why It Is Necessary?
 Damage resulting from impact can cause a loss of
50-60% of the undamaged static strength.
 Detection of low velocity impact damage is very
difficult and it is also difficult to access the resulting
deep cracks in the composite material to facilitate
repair.
 The damage can be divided into two types:
Macro damage.
Micro damage.

6. Macro Damage:
 It is mainly results from extensive delaminating,
ply-buckling and large-scale fracture and can be
visually detected and repaired with reasonable
ease.
Micro Damage:
 It is barely visible, consisting of small
delimitations, ply-cracks and fiber-fracture,
occurs mainly inside the composite material, and
is difficult to detect and repair.
 Others kinds of damage are namely shear-cracks,
delaminating, longitudinal matrix-splitting,
fiber/matrix debonding, fiber fracture.

7. Procedure:
 Polymeric coating materials are particularly
susceptible to natural or artificial degradation.
polymer degradation may come in the formation
of micro cracking that would reduce material’s
mechanical properties and shorten its lifetime.
 To overcome this the glass tubes filled with Resins
lie under the surface of the material and hence
breaks when a crack is form on that surface.
Hence the resins acts as a healing agent and heals
material cracked.

9. Materials used.
Composite Materials:
Polymer composites are advanced materials that are
made from carbon, glass and a resin, such as epoxy,
vinyl ester or urethane. Epoxy is a thermosetting
polymer.
Microencapsulated healing agent:
This is the glue that fixes the micro cracks formed in the
composite material.
Catalyst:
In order to polymerize, the healing agent must come
into contact with a catalyst. A patented catalyst,
called Grubbs‘ catalyst, is used for this self-healing
material.

11. Types of Self healing
Intrinsic Self-healing:
 Intrinsic self-healing means that the polymer matrix
themselves intrinsically have self-healing properties
that can heal after damage occur, although it still
need external stimulation.
 so some materials under go physical or chemical
interaction where rearrangements of bonds occurs.
Extrinsic Self-healing:
 In this condition the self healing agent is introduced
or pre-embedded into polymer matrix.

12.  Beside encapsulation, self-healing agent could also
loaded in pipeline within the matrix.
 When crack occurs, mechanical force would destroy
the capsule or pipeline and triggers the release of self-
healing agent.
 The self-healing agent would reach the site of cracking
and interact chemically with polymer matrix to close
and heal the crack.

13. Ways of healing.
Thermal Triggered Healing:
 a thermally triggered self-healing material was
prepared by blending a high-temperature epoxy
resin with a thermoplastic polymer.
 When a micro crack forms in the composite
material, it will spread through the material.
 By doing so, this crack will rupture the
microcapsules and release the healing agent.
 This healing agent will flow down through the
crack and combine with catalyst, which initiates
polymerization.
 the self-healed composite material regained as
much as 75 percent of its original strength.

14. Electrical Triggered Healing:
 In the case of Electrical triggering electricity sent
across the structure.
 when the current travels around a crack, its resistance
increases.
 This heats the composite and the crack, which melts
the healing agent, which then flows into the crack and
returns the structure to 70% of its original strength.
 This would lead to fuel savings, cutting costs for
airlines and passengers and reducing carbon
emissions too.

15. After healing
Healing process

16. Advantages:
 Provide continuous healing over lifetime.
 Integrate the material surface without any
ridges.
 80-90 % recovery of mechanical strength.
 Life period can be increased.
Limitations:
 Undesirable weight is going to add to the space
shuttle.
 Sufficient number of hollow tubes destroys the
integrity of original material.
 once the healing agent has been used up, the
material loses its self-healing ability.

17. Conclusion.
 when the surface gets destructed then the epoxy-
resin from the glass tube comes in contact with
the curing agent and get solidifies at that area.
 To get solidified , different healing process needs
different condition like thermal energy, electrical
energy and combination of these.
 Air and atmospheric conditions is required for
some of the healing process where as other
healing process are independent.
 This advanced technology is still under research
in the field of Aircrafts. Our idea is to use these
concepts on spacecrafts.

18. Literature views.
This type of technology was proposed in 2004 by
‘REAN GRIFFITH’ under his paper “Design and
implementation of Self-Healing systems”.