Computer chips have been shrinking every year,
and they require the complicated placement of trillions
of tiny wires. This is getting difficult, though,
as we are reaching limits to how small we can focus light,
the traditional method of making small patterns such as wires.
Our group is looking for new ways to pattern even smaller
wires, that have the additional feature of being able
to assemble spontaneously.
We use a strategy involving diblock copolymers,
which are large molecules made of two polymers
that are bound together and act as chemically distinct blocks.
These blocks would rather not be neighbors, so they
spontaneously separate, kind of like oil and water,
but on a smaller scale.
When they are put on a surface, they are able to form
wire-like cylinder structures, but these cylinders usually form
in a partially disordered pattern, making them unsuitable
for most applications. Recently, we have discovered
strategies for controlling their behavior in three dimensions.
Here's how we do it:
We use barriers, which are made of silica-like materials,
and which are used to order the cylinders as they form.
We chemically alter the barriers to be repulsive
to the self-assembled cylinders, and then introduce
the diblock copolymers to the surface, allowing them to
Here we are looking at a simulation, but let's look at
an actual experimental result, as seen
with an electron microscope.
This is what the final product looks like.
By precisely choosing the correct barrier positioning
and size, we can control the self-assembly to create
complicated 3D networks of cylindrical wires
that may one day find their way into your next computer.