Dandan Lin

Fabrication, assembly, and electrical characterization of CuO nanofibers

The authors report on the assembly and electrical properties of ultralong copper oxide (CuO) nanofibers prepared by electrospinning method. The prepared CuO nanofibers were polycrystalline, with diameter of ∼60nm and length over 100μm. By a specially designed fiber collector, single CuO nanofiber field-effect transistor (FET) was assembled directly. Electrical transport measurement was conducted on the nanowire FET device, showing that CuO nanofibers are intrinsic p-type semiconductor. Electrospinning is thus proposed as a simple and low-cost method of fabricating one-dimensional semiconductive ceramic FETs.

Enhanced UV photoresponse from heterostructured Ag–ZnO nanowires

Photoactive material consisting of heterogeneous Ag–ZnO nanowires (NWs) was prepared by electrospinning. Tunable UV photodetectors fabricated using Ag–ZnO NWs have shown high sensitivity up to over four orders of magnitude with relatively fast and stable response speed. The mechanism for this colossal photoconductivity is elucidated by means of the efficient exciton dissociation under UV illumination due to accelerated electron transfer from conduction band of ZnO to Ag nanoparticles. The facile process proposed here may pave the way for designing sensing and imaging systems.

Biomimetic nanofiber patterns with controlled wettability

Fast and easy construction of biomimetic surfaces with controlled wettability was accomplished through electrospinning. The topography and wetting properties of biosurfaces including lotus leaves, bamboo leaves, goose feathers and water striders legs were mimicked with different patterns of electrospun polymer nanofibers. Surfaces with anisotropic wetting in two or three directions, as well as artificial water striders legs with maximal supporting force of more than 200 dynes cm−1 were facilely fabricated based on an electrospinning technique combined with specially designed nanofiber collectors. We believe these polymer nanofiber patterns will help the design of smart, fluid-controllable interfaces that may be applied in novel microfluidic devices and directional, easy-cleaning coatings.

Electrical behavior of electrospun heterostructured Ag-ZnO nanofibers

In this work, the electrical behavior of heterostructured Ag–ZnO nanofibers was studied by varying the Ag content. The electric conductivity of the hybrids follows the percolation theory and can reach as high as 115 S cm−1 due to the electron transfer highway provided by Ag phase. Typical low-voltage varistor behavior, with nonlinear coefficient of ∼10, was observed for samples with proper Ag concentration. Possible mechanism was elucidated by means of the morphology and distribution of Ag additives throughout the ZnO host.