MeV ion nanobeams: nanotechnology for the 21st century

The huge upsurge in interest in nanotechnology has started a wide-ranging hunt for new ways of cutting, shaping, manipulating and observing matter on a very small scale.The research we propose is part of this hunt and will result in new tool for nanotechnology, the MeV Nanobeam, which will produce an extremely finely focused beam of protons or other ions accelerated through a few million volts in a nuclear accelerator. This can be used in two ways. First as a sharp pencil to draw patterns on suitably sensitive materials. These can be processed to create complex structures which have very small lateral dimensions (tens of nanometres) but with straight sides for depths of tens of micrometres. Secondly the beam can be used as a sensitive probe to allow us to do chemical analysis of objects on the nanometre scale.These unique capabilities result from the physics of the interaction between high energy protons and the atoms of the samples, which is such that the particles penetrate for long distances (around 100 micrometres) without being deflected from a straight line path, yet at the same time they transfer enough energy to atoms in the locality of the ion tracks so that the solubility may change (to allow structures to be made) or radiation may be emitted which allows us to identify the chemical elements present.The early stages of the the project will be taken up with the task of designing and building the Nanobeam. This will be underpinned by our lin depth experience in developing microfocused ion beam systems together with newly available software tools for modelling ion paths in complex magnetic fields. In the later stages of the project we will demonstrate the capabilities of the system in a wide range of applacations.The potential applications of tiny nano structures made in glass, plastic and semiconductors using the new facilities are limitless, but we will explore the possibility of producing demonstration components for devices to be used in opto-electronics (communicating and computing with light), micro-fluidics (doing chemistry with minute quantities of reagents) and NEMS (nano-electro-mechanical systems which interface mechanical devices such as motors with electronic integrated circuit chips). A particularly exciting field will be the emerging technologies at the life-sciences interface such as drug delivery devices or specially textured surfaces used as 'tissue scaffolds' to encourage the healing of injuries.In addition to nano-engineering this versatile system will also be used for nanoanalysis, enabling maps and depth profiles to be obtained for all elements beyond He in the periodic table. This has applications in practically every field of science and technology with examples ranging from understanding grain boundary effects in diamond radiation detectors and mapping lattice strain fields in SiGe, to determining the composition of fine fraction ambient aerosols and investigating at the role of metals such as aluminium in digestion or neurodegenerative diseases.