Problems associated with large-scale pattern growth of graphene constitute one of the main obstacles to using this material in device applications. Recently, macroscopic-scale graphene films were prepared by two-dimensional assembly of graphene sheets chemically derived from graphite crystals and graphene oxides. However, the sheet resistance of these films was found to be much larger than theoretically expected values. Here we report the direct synthesis of large-scale graphene films using chemical vapour deposition on thin nickel layers, and present two different methods of patterning the films and transferring them to arbitrary substrates. The transferred graphene films show very low sheet resistance of approximately 280 Omega per square, with approximately 80 per cent optical transparency. At low temperatures, the monolayers transferred to silicon dioxide substrates show electron mobility greater than 3,700 cm(2) V(-1) s(-1) and exhibit the half-integer quantum Hall effect, implying that the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene. Employing the outstanding mechanical properties of graphene, we also demonstrate the macroscopic use of these highly conducting and transparent electrodes in flexible, stretchable, foldable electronics.

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.

We employ the CRISPR-Cas system of Streptococcus pyogenes as programmable RNA-guided endonucleases (RGENs) to cleave DNA in a targeted manner for genome editing in human cells. We show that complexes of the Cas9 protein and artificial chimeric RNAs efficiently cleave two genomic sites and induce indels with frequencies of up to 33%.

The conductivity of graphite oxide films is modulated using reducing agents. It is found that the sheet resistance of graphite oxide film reduced using sodium borohydride (NaBH4) is much lower than that of films reduced using hydrazine (N2H4). This is attributed to the formation of CN groups in the N2H4 case, which may act as donors compensating the hole carriers in reduced graphite oxide. In the case of NaBH4 reduction, the interlayer distance is first slightly expanded by the formation of intermediate boron oxide complexes and then contracted by the gradual removal of carbonyl and hydroxyl groups along with the boron oxide complexes. The fabricated conducting film comprising a NaBH4‐reduced graphite oxide reveals a sheet resistance comparable to that of dispersed graphene.

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To find use in electronics, single-walled carbon nanotubes need to be efficiently separated by electronic type and aligned to ensure optimal and reproducible electronic properties. We report the fabrication of single-walled carbon nanotube (SWNT) network field-effect transistors, deposited from solution, possessing controllable topology and an on/off ratio as high as 900,000. The spin-assisted alignment and density of the SWNTs are tuned by different surfaces that effectively vary the degree of interaction with surface functionalities in the device channel. This leads to a self-sorted SWNT network in which nanotube chirality separation and simultaneous control of density and alignment occur in one step during device fabrication. Micro-Raman experiments corroborate device results as a function of surface chemistry, indicating enrichment of the specific SWNT electronic type absorbed onto the modified dielectric.

Recently, there has been great interest in flexible and wearable energy devices for applications in flexible and stretchable electronics. Even though future developments are moving toward thinner, lighter, and cheaper solutions, [1,2] many existing energy-harvesting and storage devices are still too bulky and heavy for intended applications. For example, high-efficiency dye-sensitized solar cells (DSSCs) employ fluorine-doped tin oxide (FTO) glass as the substrate of working electrode. However, the use of rigid FTO glass has restricted adaptability of DSSCs during transportation, installation, and application, [2] requiring further development of flexible cells to improve DSSC adaptability. To develop flexible and wearable electronics, not only new materials for the substrates used in energy storage devices such as batteries and supercapacitors need to be explored, but future development of higher performance energy systems still depends on the employment of new and lighter electrode materials.In recent years, electrochemical supercapacitors have attracted much attention as novel energy-storage devices because of their high power density, long life cycles, and high efficiency. [3][4][5][6][7][8][9][10][11][12] Supercapacitors can deliver higher power than batteries and store more energy than conventional capacitors. [13,14] Current research on supercapacitors has focused on their applications in electric vehicles, hybrid electric vehicles, and backup energy sources. Thus, conventional supercapacitors are heavy and bulky, and it is still a challenge to achieve high efficiency miniaturized energy-storage devices that are compatible with the flexible/wearable electronics. [15] Herein, we present a prototype of a high-efficiency fiberbased electrochemical microsupercapacitor using ZnO nanowires (NWs) as electrodes. These fiber supercapacitors, which have great potential for scale-up, comprise two electrodes that employ a flexible plastic wire and a Kevlar fiber as a substrate. Both wire and fiber are covered with arrays of highquality ZnO NWs grown by the hydrothermal method, and ZnO NWs on a Kevlar fiber was coated with a thin gold film to improve the charge-collection capacity. Furthermore, employment of ZnO NWs could provide exciting solutions to the future development of wearable energy devices. Our fiber-based microsupercapacitor would be large enough to be used in self-powering nanosystems, such as a power shirt using piezoelectric ZnO NWs grown radially around textile fibers.Even though conventional research efforts on bulky supercapacitors have focused on the use of carbon-based materials, such as activated carbons, and some transition metal oxides, such as RuO 2 and ZnO, could have several advantages over the conventional electrode materials of supercapacitors for the wearable electronics. First, it can be grown at low temperatures (less than 100 8C) by a chemical approach on any substrate and any shape substrate. Second, it is biocompatible and environmentally friendly material. Furthermore, ZnO NWs [16][17...

A hybrid-fiber nanogenerator comprising a ZnO nanowire array, PVDF polymer and two electrodes is presented. Depending on the bending or spreading action of the human arm, at an angle of ∼90°, the hybrid fiber reaches electrical outputs of ∼0.1 V and ∼10 nA cm(-2) . The unique structure of the hybrid fiber may inspire future research in wearable energy-harvesting technology.