A review of shape memory alloy research, applications and opportunities

Graphene oxide: preparation, functionalization, and electrochemical applications.

We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.

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Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems

Surface plasmons (SPs) are coherent oscillations of conduction electrons on a metal surface excited by electromagnetic radiation at a metal -dielectric interface. The growing field of research on such light -metal interactions is known as ‘plasmonics’. 1-3 This branch of research has attracted much attention due to its potential applications in miniaturized optical devices, sensors, and photonic circuits as well as in medical diagnostics and therapeutics. 4-8

Nanostructured plasmonic sensors.

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Micro Total Analysis Systems. 1. Introduction, Theory, and Technology

Proton beam writing

We experimentally demonstrate at terahertz frequencies that a planar metamaterial exhibits a spectral response resembling electromagnetically induced transparency. The metamaterial unit cell consists of a split ring surrounded by another closed ring where their dimensions are such that their excitable lowest order modes have identical resonance frequencies but very different lifetimes. Terahertz time-domain spectroscopy verifies that the interference of these two resonances results in a narrow transparency window located within a broad opaque region. In contrast to previous studies this enhanced transmission is achieved by independently exciting two resonances in which their coupling to the radiation field, and thus their linewidth, differs strongly. Rigorous numerical simulations prove that the transparency window is associated with a large group index and low losses, making the design potentially useful for slow light applications. This experiment opens an avenue to explore quantum-mechanical phenomena using localized resonances in metallic structures.

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Analogue of electromagnetically induced transparency in a terahertz metamaterial

To overcome the diffraction constraints of traditional optical lithography, the next generation lithographies (NGLs) will utilize any one or more of EUV (extreme ultraviolet), X-ray, electron or ion beam technologies to produce sub-100 nm features. Perhaps the most under-developed and under-rated is the utilization of ions for lithographic purposes. All three ion beam techniques, FIB (Focused Ion Beam), Proton Beam Writing (p-beam writing) and Ion Projection Lithography (IPL) have now breached the technologically difficult 100 nm barrier, and are now capable of fabricating structures at the nanoscale. FIB, p-beam writing and IPL have the flexibility and potential to become leading contenders as NGLs. The three ion beam techniques have widely different attributes, and as such have their own strengths, niche areas and application areas. The physical principles underlying ion beam interactions with materials are described, together with a comparison with other lithographic techniques (electron beam writing a...

Ion beam lithography and nanofabrication: a review

The Research Centre for Nuclear Microscopy, National University of Singapore incorporates three state-of-the-art beam lines, connected to a high brightness High Voltage Engineering Europa 3.5 MV Singletron accelerator. One of these lines is a NEC (National Electrostatics Corporation, USA) ion channeling facility, utilising broad beam ion beam analysis techniques for advanced materials research. The other two lines are microbeam facilities; one is designed for nuclear microscopy of biomedical samples and advanced materials, where relatively high currents (>50 pA) are required, and the other for proton beam micromachining (PBM) and materials modification, where lower currents can be utilised. The resolution performances of the two microbeam lines have been measured, and the results are as follows: (1) The nuclear microscope line incorporates the Oxford Microbeams OM2000 endstation with the OM50 quadrupole lenses configured in the high excitation triplet mode. This line has achieved the world’s best performances for analytical applications of 290 × 400 nm for a 50 pA current of 2 MeV protons. (2) The PBM line, which is the first of its kind worldwide, utilizes the new generation of compact (OM52) quadrupole lenses (Oxford Microbeams Ltd.) also configured in a high excitation, triplet configuration. This facility, which has superior demagnification properties, has achieved the world’s best performances for low current applications. Spot sizes of 35 × 75 nm have been measured using direct scanning transmission ion microscopy for beam currents of 10,000 protons per second.

The National University of Singapore high energy ion nano-probe facility: Performance tests☆

We report the utilization of a focused mega-electron-volt (MeV) proton beam to write accurate high-aspect-ratio structures at sub-100 nm dimensions. Typically, a MeV proton beam is focused to a sub-100 nm spot size and scanned over a suitable resist material. When the proton beam interacts with matter it follows an almost straight path. The secondary electrons induced by the primary proton beam have low energy and therefore limited range, resulting in minimal proximity effects. These features enable smooth three-dimensional structures to be direct written into resist materials. Initial tests have shown this technique capable of writing high aspect ratio walls of 30 nm width with sub-3 nm edge smoothness.

Andrew A. Bettiol

Papers

Proton beam writing

Analogue of electromagnetically induced transparency in a terahertz metamaterial

Ion beam lithography and nanofabrication: a review

The National University of Singapore high energy ion nano-probe facility: Performance tests☆

Three-dimensional nanolithography using proton beam writing