New nanodevices for force/mass measurements and data storage: design and characterisation

It has been only a decade since nanomanufacturing, a new area of nanotechnology, has emerged that combines chemistry and fabrication to produce precise devices at the nanometer scale. And what a successful time it has been! During this period, it has become possible to control the position of molecules with 0.1 nm precision, to operate nanomachines at extremely high frequencies exceeding 10^9 Hz, to produce logic gates that switch in 0.1 ns and dissipate less than 10^{-21} J of energy, to convert power greater than 10^9 W/m^3, to build macroscopic components with tensile strength greater than 5x10^{10} Pa. Each of these capabilities is an aspect of nanomanufacturing that is continually improving.This proposal exploits fully the new area of nanoscience and suggests advanced designs and working prototypes of new nanodevices in the areas of electromechanics and quantum computing, with the ultimate goal to prepare them for integrated fabrication. To achieve the power of measuring the absolute mass of a single molecule, an ultrahigh frequency nanoresonator based on the thermal vibrations of double-walled carbon nanotubes will be developed and characterized. Due to the small effective mass of its vibrating parts, the nanoresonator has an extremely high sensitivity to the additional mass of just a few molecules. A fast response to applied forces makes it capable of measuring extremely weak forces reaching attonewton accuracy. Carbon nanotubes are the focus of a worldwide research effort, due to their exceptional mechanical and electronic properties. They present a wide range of conductive behaviour, from semiconductor to superconductor. These properties make carbon nanotubes an ideal candidate for integration into nanoscale electronic circuits to build a new generation of computers. The electronics industry is searching for a replacement of silicon based technologies for data storage and computer memory. Existing technologies, such as magnetic hard disks, cannot be used in the sub-micrometer scale machines and will soon reach their fundamental physical limitations. In this proposal, a new device for storing information will be developed, which is made entirely of carbon nanotubes and combines the speed and price of dynamic memory with the nonvolatility of flash memory. A critical assessment of the potential and capacity of carbon nanotubes, empty and filled with material, as nanowires with tunable properties will also be undertaken.The research will be undertaken at the University of Nottingham, where a collaborative capability between the Schools of Chemistry, Physics and Pharmacy, and the Nottingham Nanotechnology and Nanoscience Centre will be established. This will provide a platform for correlating multiscale modelling and theory development with state of the art characterisation and measurements of physical properties of carbon nanotubes and advanced functional materials. This will bring together otherwise disparate strengths in atomic resolution materials characterisation, experimental nanometrology and both quantum mechanical and classical modelling in order to target the proposed device development. A theoretical group, based at the School of Chemistry and led by the Applicant, will be working on the development of a multiscale modelling of the physical and chemical properties of carbon nanotubes filled with nanocrystalline solids, and the development and theoretical characterisation of novel nanodevices based on carbon nanotubes. Experimental groups, funded by the Schools of Pharmacy and Physics and co-supervised by the Applicant, will devote their work to experimental electrical and structural characterisation of the new nanotube devices.