home projects publications contact us events jobs University
Bone
Bone in general is very tough, particularly antler
bone, and bird bone is very stiff, yet birds still manage to fly. The ceramic content of
bird bone is extremely high. We have researched this in greater detail with a view
to considering the nature of the stiffness of bone, and whether that can be mimicked using
other components. We have studied the toughening mechanisms of antler bone to suggest
ideas for tougher helmets and general impact protection.
Expanded starch
In a Government funded project, we examined the
potential of expanded starch in the search for the replacement of moulded polystyrene.
Extruded starch has already been used as a replacement for loose fill polystyrene
granules, but we aim to take the concept a stage further, and produce a starch product
which can be shaped, cut or moulded, such as in the packaging materials found around most
electrical goods. The benefits are obvious: the product can be recycled without
difficulty, is fully biodegradable, since it would be a natural water based substance, and
it could be much cheaper than the standard oil based polystyrene product.
Food texture
In a series of pieces of research which have
applications in the processed food industry, we have designed new methods for the analysis
of crispness in the texture of food. This is mainly applicable in the areas of fruit,
vegetables and cooked starch based products.
Gels
The principle of a fluid enclosed in a membrane
being made to do useful work can be seen in our own muscular system, plants, and in the
skin of worms. The skin of a worm is effectively a cylinder comprised of fibres that
are wound in a crossed helical form around and along the worm's body. By contracting
the muscles in the body wall and increasing its internal pressure the worm is able to
change shape, with the fibres in the skin allowing the worm to go from short and fat to
long and thin. This is the basis of a worm's locomotory mechanism. Using
cylinders of various fibre angles and by replacing the worm's muscles with a polymer gel
which can absorb water, we can design the swelling and contracting of the gel to do useful
work. Chemical energy is converted to mechanical energy just where it is required
and any pressure developed is confined to the helically-wound bag, which is intrinsically
safe. Therefore, by controlling the swelling and contracting of the polymer gel, the
system effectively works as an artificial muscle.
Insect sense organs
Funded by EU FP5, we have used finite element
modelling to understand the design of sensors in insect cuticle. We aim to
incorporate similar designs into aerospace composite materials. Preliminary results
suggest that they are very sensitive detectors and permit remote interrogation for strain.
Present work is concentrating on the hair-like airflow receptors found on the
cerci of crickets. For further details, visit the project website (http://www.bionics-cicada.org).
Plant fibres
We are examining plant fibres, principally flax and
hemp, with a view to replacing glass fibre in low priced products, especially building
materials. Glass fibre, when used in cement boards and phenolic boards, for example,
cannot be recycled, nor can it be incinerated. In using plant fibres as a stiffening
filler in such products, the products could then be re-used, perhaps as fuel, since they
could be incinerated. The fibres can be produced by crops grown in the European Union.
Smart fabrics
By carrying out research on the opening and closing
of pine cones and the insulation layers of penguins, we have worked on the principles of
design of a fabric which can be used to make responsive clothing, with transpirational
properties based on the state of activity of the wearer. This is of particular interest in
the defence industry, meaning that the minimum of layers of clothing need be worn at all
times, particularly in areas of the world with widely fluctuating temperatures: a soldier
in the deserts around the Gulf will otherwise need few layers by day in the baking heat,
but lots of layers by night in the chill of the sand.
Wood
The Centre for Biomimetics has created a material
which uses one of the toughening mechanisms found in wood and which has in particular high
resistance to impact. Now our researchers are working on a project which takes the
composite one stage further, making it particularly useful in the field of protection
against high velocity particles such as bullets, shrapnel from bombs or being attacked
with a knife.
In another project, we are looking at the mechanical properties of wood from transgenic trees with reduced lignin content. By exploiting genetic engineering techniques, it should be possible to reduce energy consumption and pollutants from the pulp and paper industries.