In this first speech, I would like to talk about what we call "nano", and why we think
it is interesting, or what global results are being achieved. Initially, the term "nano"
arose in the late 50s, within a speech given by Richard Feynman (later awarded
with a Nobel Prize) in which he explained how matter could be manipulated
at a nanometric scale. He essentially explained how to manipulate groups of atoms
in order to do something as simple as writing a book on a very small surface.
This was the first concept of "nano", for which it would be necessary to develop nano-machines
and nano-instruments, in order to be able to modify those nanostructures.
Well, it took such a simple idea 20 years to be developed, in the tunnel effect microscope
(1981), and 12 years on top of that were necessary in order to individually manipulate
atoms. What we have here is a group of 48 atoms forming a circumference, 
placed on a copper 1:1:1 surface. Igler's research group did it, at IBM, in 1993.
Nevertheless, as time goes by, we realise that "nano" does not just mean "smaller",
as Microtechnology implied, but also that, when we reduce matter to a nanometric scale,
to about 100 nanometres and less, it presents new phenomena, we have a different behaviour.
Therefore, "nano" will mean "little" (typically 100 nanometres) but it will also mean "different".
"Different", sometimes it will be better and sometimes it will be worse.
But, why is it "different"? At a macroscopic scale classical Physics dominate
the behaviour of matter, but at a nanometric scale we have to take into account
quantum phenomena. For example, if we confine an electron in an ever shrinking area,
its power levels will suffer modifications. Specifically in semiconductors,
for instance Cadmium Selenide, we have the conduction and valence bands defined.
If we reduce matter to a nanometric scale, 5 or 10 nanometres, we have these particles
and the power levels change dramatically, and that will allow us to design devices.
Second aspect: the surfaces. When we have a massive material -centimetres-
there are very few atoms on the surface. However, proportionally, when we reduce
the size of the particles, there is a higher percentage of atoms on the surface every time.
Therefore, all the phenomena linked to catalysis are going to be altered.
In particular, the coordination of atoms on surfaces is different: we have free bonds
and thus we expect a higher reactivity of the materials. And a troubling fact,
if you want to see it that way, is that when we try to reduce these micro devices,
called MEMS (Micro Electro Mechanical Systems), to Nano Electro Mechanical Systems
the friction is so strong that these devices stop working and we will have to find
other routes, it is not as simple as making them smaller and smaller every time.
If we consider a sphere of about 100 nanometres we hardly have any atoms on the surface,
but we can see that as we pass 50 nanometres, the amount of atoms on the surface
increases more each time. Even gold -as has been published- becomes reactive.
Which are the nano-structured materials? Well, although there are many classifications,
we will take a classification based on how many dimensions are "nano".
Firstly, perhaps the most characteristic or the most famous, are the zero-dimensional
nanostructured materials. This means that all the dimensions of the material
are below 100 nanometres. One example of this could be the semiconductor quantum dots
I mentioned before. We can see that when the size is 2 nm, they show a blue emission
and that emission becomes red when we increase the size of the particle, always
in the nanometre range. This allows us to design solid-state laser type devices 
and we can also, if we properly functionalize these particles and introduce them
into the human body, use them as biomarkers.
I said before that "nano" is "different". Well, materials such as lead titanate
and lead zirconate, which are ferroelectric materials, when reduced to a nanometric size
(50 nm and below), loose the tetragonality of their crystal structure and therefore
they lose their ferroelectric character. Another well known type of nanomaterials
are the nano-tubes. Perhaps the best known are the carbon nano-tubes, which have
very special properties in terms of conductivity, which depends on the chirality of the nano-tube, 
and also present very important mechanical properties. Therefore, we will turn to them
whenever we need conductivity and certain mechanical properties, such as toughness.
Thin films are another typical example of nano-structured devices. They allow us to manufacture
solar cells and coatings, which will be used as optical filters, for example. There is an example
of nano-structured material that we use every day, in digital cameras, in computers, in iPads...
which are also thin films. In this case we have drawn a so-called spin valve, which consists
of two ferromagnetic layers separated by a non-magnetic spacer. When the emission
of the two ferromagnetic layers is parallel, we get one resistance value, and when it is anti-parallel
we get a different resistance value. That means that we have 1s and 0s, which means
that computer memories are actually based on this type of devices. Of course, if you reduce
the size of these bits too much, problems like super-paramagnetic effects arise,
which imply that we have to study new materials with different features,
or new information storage techniques.
Finally we have the so-called "Bulk nano-structured materials", which are,
as their name indicates, large/macroscopic materials that, either because their grain size
is in the nanometre range or because we have a nano-sized second phase dispersed
within the matrix, suffer alterations to their mechanical properties (in this case I am referring
to the alumina nanocomposite). 
Finally, I wanted to comment that "nano" is not really a product for the future but rather
a product that we already have in our lives, as I said when I mentioned computer memories,
but there are also other types of systems (clothing, dental prosthesis, different types
of sensors...). What this graphic indicates is not only that "nano" is present,
but that it is going to be ever more present. This is all I wanted to say.
