This paper describes the first example of the patterning of surfaces via nanocontact printing with chemically distinct features in the <50 nm scale over 3 × 3 mm2. These ultrasmall features are achieved via a combination of “sharp” and “hard” poly(dimethylsiloxane) stamps, keeping the contact area in the 50 nm domain, and high molecular weight inks to avoid diffusion. The patterns consist of dendrimers or proteins and can be used as a scaffold for further modification with gold nanoparticles.

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We demonstrated a high-repetition-rate Q-switched fiber laser with topological insulator Bi₂Se₃ absorber. The absorber was made into a film structure by spin-coating method using few-layer Bi₂Se₃ nano-platelets which had regular shape. The uniform film had a low saturable optical intensity of 11 MW/cm(2), which is the lowest saturable optical intensity in the saturable absorbers made by topological insulator till now. By inserting the absorber film into an Erbium-doped fiber laser, a high-repetition Q-switched laser with the repetition rates from 459 kHz to 940 kHz was achieved. The maximum output power was 22.35 mW with the shortest pulse duration of 1.9 μs. To the best of our knowledge, both of the repetition rate and the output power were the highest values among the Q-switched fiber lasers with topological insulator absorber.

Structural health monitoring (SHM) provides a useful tool for ensuring safety and detecting the evolution of damage and performance deterioration of civil infrastructures. A great number of civil infrastructures under construction can be used as test beds for SHM systems. The Binzhou Yellow River Highway Bridge is a cable-stayed bridge in Shandong Province, China. An SHM system has been implemented on this bridge during its construction for monitoring its health status and assessing its safety for long-term services. The system includes a sensor module, a data acquisition module, a wired and wireless data transmit module, a structural analysis module, a database module, and a warning module. It is integrated by using LabVIEW software and can be remotely operated via Internet. The database is available freely to all scientists and engineers in the SHM research area. This article introduces the deployment and functions of this system, and presents the measured responses of the bridge subjected to moving vehicle loads.

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Different graphene inks have been synthesized by chemical methods. These uniform dispersions were stabilized by various functional groups such as room temperature ionic liquid, polyaniline, polyelectrolyte (poly[2,5-bis(3-sulfonatopropoxy)-1,4-ethynylphenylene-alt-1,4-ethynylphenylene] sodium salt) and poly(styrenesulfonate) (PSS). The dispersions can be easily cast into high-quality, free-standing films but with very different physiochemical properties such as surface tension and adhesion. SEM and AFM methods have been applied to have a detailed study of the properties of the inks. It is found that graphenes modified by p-type polyaniline show the highest surface tension. Diverse surface adhesive properties to the substrate are also found with various functional groups. The different viscoelasticities of graphene inks were related to the microscopic structure of their coating layer and subsequently related to the configuration, chemistry and molecular dimensions of the modifying molecules to establish the property-structure relationship. Modifications of graphene inks made from chemical reduction cannot only enable cost-effective processing for printable electronics but also extend the applications into, for example, self-assembly of graphene via bottom-up nano-architecture and surface energy engineering of the graphenes. To fabricate useful devices, understanding the surface properties of graphene inks is very important. It is the first paper of this kind to study the surface tension and adhesion of graphene influenced by different functional groups.

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