Abstract
Although water is one of the most widespread material on the earth's surface and the most directly involved in a large number of phenomena, both natural and man-made; and although its molecule is made up of just 3 atoms, it still conceals many mysteries. Not all its physical and chemical properties are yet fully understood, especially when it is confined to nanometric spaces. It is therefore still the subject of in-depth fundamental studies. However, the many technical difficulties encountered when working at the nanometric scale mean that today, most published studies are theoretical rather than experimental. The need for experimental data is thus essential. This is the general framework to the experimental research reported in this thesis. The work carried out can be divided into two distinct parts, each of which aims to make a contribution to the current and futur experimental studies which will be carried out on water in a confined environment.The first part of the project involves the development of an experimental protocol for fabricating micro-platforms that are impervious to liquid water, partial water vapor pressure or vacuum. The fabrication of these microsystems is based on microlithography techniques and the use of SU-8 resin. We show that it is possible to produce waterproof and vacuum-tight microsystems with SU-8 walls no thicker than 100µm and 30µm high. The proposed protocol is therefore perfectly suited to the realization of Lab-on-Chip/nanofluidic micro-platforms dedicated to the study of water confined in a nanopore and to water nanofluidics.The second part reports on a study of the impact of water on the electrical behaviour of µ-field-effect transistors made of a single carbon nanotube channel (CNTFET). Microelectronics techniques to design and manufacture a µ-platform consisting of several microelectrodes in contact with a single nanotube are used. These electrodes made it possible either to carry out electrical measurements or, using the Joule effect, to open the nanotube at specific points and to heat it to temperatures high enough to eliminate all traces of water from its environment. The electrical response of the CNTFET as a function of the environment around the nanotube, i.e. liquid water, ambient air, vacuum, is analysed. A comparison is made between the responses obtained when the nanotube is closed or open. It is thus possible to propose a simplified qualitative model of interaction with water, and to distinguish the impact created by water adsorbed outside the tube from that associated with water confined within the tube. This pioneering work opens up many new prospects on water in the fields of nanofluidics and fundamental studies about its structure and the dynamics of its molecules in a confined environment. First and foremost, it will be used to develop a µ-measurement platform based on the electromechanical characteristics of a single carbon nanotube in the presence of water either solid, liquid ou vapour.