Transcript 17. Smart and modern materials (not covered in lessons) File

Smart and Modern Materials – what
you need to know
1. Including polymorph, thermochromic inks pigments
and films, photochromic inks and pigments,
phosphorent pigments, fluorescent pigments and the
response of these materials to external factors and
their suitability for different situations.
2. Other smart and modern materials as they become
available.
3. Be aware of developments in nanotechnology as they
emerge, for example NanoComposites, NanoCrystals,
NanoClays, NanoStructured materials, NanoParticles
and NanoTubes and how they are used in products
such as glues, packaging, paints, coatings, displays
and fabrics.
Smart Materials
Definition – they sense conditions in their
environment and respond to these
conditions. They appear to think and have
a memory as they will revert back to their
original state time and time again.
Know that some smart materials respond to
changes in temperature, light or applied
voltage.
Modern Materials
Modern materials are developed through the
invention or creation of new or improved
processes. Many modern materials are
developed for specialised applications, such as
space exploration, but some eventually become
available for general use.
Thermochromic colours
• Change colour in response to a
temperature change. Colour
disappears above 27degress and
reappears below that.
Thermochromatic pigments are
supplied in paste form and can be
mixed with any type of acrylic paint.
At normal room temperature the
pigment shows its usual colour, but
when heated above 27°C the colour
changes to black. When the
temperature falls below 27° C again
the colour reappears.
Thermocolour sheet is a sheet
material printed with thermochromic
liquid - that is, one that changes
colour as the temperature changes.
Smart grease – a gel that can be used to
slow mechanical systems to provide
smooth movement.
Smart images – thin polyester films with
emobossed holographic-effect metal foils
often giving a three dimensional effect.
Seen on packaging, credit cards and
point of sale displays.
Smart wire – is an
engineered alloy that
changes length or
shape in response to a
temperature change.
Used to activate small
mechanisms.
Phosphorescent pigments – store light energy
from natural/artificial light and provide a
unique afterglow (glow in the dark) For
example if the numbers on a watch face are
printed in phosphorescent pigment they will be
visible at night. Also commonly used for safety
signs. Phosphorescent pigments are
pigments which glow in the dark, first
absorbing light and then emitting it after the
light source has been removed.
Photochromic inks – colours change in
response to a change in the level of light. For
example a message printed onto a T-shirt in
photochromic colours will appear in the strong
sunlight and disappear once the person has
moved into the shade. Photochromic colours
have many novelty applications.
 Polymorph is a plastic that becomes mouldable
at 62°C. It can be used for productmodelling, especially where curved shapes are
involved (for example handles), and for making
simple moulds for vacuum-forming.
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Treated papers are available for computer printers, especially for ink-jet
printers. They absorb the ink and generate crisp colour reproduction.
Thermochromatic pigments are supplied in paste form and can be mixed with
any type of acrylic paint. At normal room temperature the pigment shows its
usual colour, but when heated above 27°C the colour changes to black. When
the temperature falls below 27° C again the colour reappears.
Phosphorescent pigments are pigments which glow in the dark, first absorbing
light and then emitting it after the light source has been removed.
Thermocolour sheet is a sheet material printed with thermochromic liquid - that
is, one that changes colour as the temperature changes.
Polymorph is a plastic that becomes mouldable at 62°C. It can be used for
product-modelling, especially where curved shapes are involved (for example
handles), and for making simple moulds for vacuum-forming.
High-density modelling foam is a foam-based material that is available in
blocks. It can be shaped easily using hand and machine tools and takes fine
detail well. It is often used on CNC milling machines.
Nanotechnology
• The science of the extremely small – involves the study and use of materials
on a very small scale.
• Nano refers to nanometre (nm) one nanometre is a millionth of a millimetre
• At such a small scale materials can behave very differently . Nanomaterials
can be stronger, lighter or conduct heat or electricity in a different way. They
can even change colour.
• Nanotechnology is used for computer chips, healthcare products, mobile
phones.
• Nanoparticles include tiny crystals (nanocrystals) and tiny tubes (carbon
nanotubes)
• Example – nanostructured copper is much harder and more rigid than
ordinary copper. Anti vandal paint is produced with nanotechnology so other
paint can not stick on top. Packaging materials can be made where the
minute gaps in the products structure are filled in with incredibly tiny bits of
clay (nanoclays) to make it extra airtight to keep food and drink fresher for
longer.
• Some people are concerned about safety as nanotechnology is so new and
we don’t yet know what the risks are.
• Look up nanotechnology on the internet.