Background Science

The final aim of the Nano2Hybrids project is to produce a pocket-sized device that can detect gases in the atmosphere, in particular, benzene. This will be attempt by developing electronic sensors based on nanotechnology.

Electronic devices that can detect the presence of particular gases in the atmosphere already exist but most of them are large, heavy and expensive. Benzene is toxic and inflammable gas. It is used in the petrochemical industry.Therefore, the use of nanotechnology to develop light, economic gas sensors is of considerable interest in the field of personal safety, particularly in industry.

Within the project, the use of carbon nanotubes in the electronic devices will be explored. Carbon nanotubes are cylinder-shaped, hollow structures, the walls of which are made up of carbon atoms. They are a few microns long (1000 microns = 1 millimetre), but they are between 1 and 15 nanometres in diameter (1000 nanometres = 1 micron).

Gas sensors try to take advantage of one of the characteristic properties of nanotubes: their electrical conductivity depends on the gas with which they are in contact. The problem is that the reactivity of nanotubes is quite low. For this reason, the research centres taking part in the project are attempting to increase their sensitivity. We will create defects in the wall of the nanotube using plasma treatments and adhering small clusters of atoms, in particular metals such as gold, silver, titanium or others, in predesigned and controlled positions.

The sensor is made by constructing a network of nanotubes, somewhat similar to a kitchen scourer, of approximately 1 mm2. The gases in the atmosphere circulate through this network. The cluster of nanotubes is connected to some electrodes and to an electric meter. The strategy of Nano2Hybrids, in the fabrication of both the nanotubes and the sensors, is to develop the production methods that have the least environmental impact and which do not generate chemical residues.