Chemistry Reference
In-Depth Information
Chapter 2
Microfluidic Membrane Networks
A concept of self-assembled soft matter devices based on
micro-fluidics, which use surfactant bilayer membranes as their
main building blocks, arrested in geometric structures provided
by top-down lithography, is outlined.
2.1 Introduction
The miniaturization of technical components and machines has been one of the most
powerful motors of advancement in both science and technology for the past four
decades. Feature sizes in modern electronic circuits have come down to the scale
of 45nm, and single transistors are meanwhile routinely made smaller than 100nm
[
1
]. As a consequence, the density of components placed on micro-chips has seen
a roughly exponential increase over many years. This development, which for its
practical robustness has received the colloquial term 'Moore's law', is at the heart of,
the enormous recent increase of widely available computer power [
2
]. All this has
been reached by means of 'top-down' lithographic techniques, which are capable
of structuring solid state materials into arbitrary shapes with amazing accuracy by
sophisticated lithographic procedures.
However, it is clear that there will soon be an end to this development of ever
smaller structuring. Well before the structures come of molecular size (
1nm),
interfacial diffusion will lead to their rapid destruction. Other transport processes
directly linked to the function of the device, such as electro-migration in electronic
chips, are even much more effective. Since the lithographic approach necessarily
leads to a structure which is very far from thermal equilibrium, this must be seen as
