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A novel and simple approach for the realization of polymer sub-micrometre channels is introduced by exploiting replica molding of Pt wires deposited by focused ion beam. We fabricate arrays of parallel channels with typical dimensions down to 600 nm and with variable height. We characterize the pressure-driven transport of polymer colloids through the channels in terms of the translocation frequency, amplitude and duration by implementing a laser scattering detection technique. We propose a prototype application of the presented platform such as the in situ sizing and sensing of populations of particles with different dimensions down to 50 nm.

We report on single nanofiber field-effect transistors made by the light-emitting polymer, poly(2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene). We measure electrical performances comparable to or better than those of thin-film transistors by the same organic semiconductor, due to the molecular alignment induced by electrospinning, such as hole mobility of the order of 10(-3) cm(2) V(-1) s(-1) and on/off current ratios up to 780. In addition, we observe controllable photoluminescence intensity quenching by varying the gate voltage up to -40 V with device operation in the luministor mode. Single light-emitting polymer nanofiber transistors coupling electrical and optical functionalities open the way towards low cost and flexible one-dimensional switches and nanofiber-based light-emitting transistors.

We demonstrate the enhancement of the polarization ratio of light emitted from electrospun conjugated polymer nanofibers, by means of nanoimprint lithography carried out at room temperature. We provide evidence of tailoring the polarization properties by patterning light-emitting fibers at the nanoscale. The polarization ratios are increased up to a factor of 2.4 by gratings with periodicity (560 nm) matching the emission wavelength of the employed conjugated polymer. The use of room temperature nanoimprint lithography to pattern light-emitting polymer nanofibers represents a strategic route for realizing photonic crystals and distributed feedback polarized emitters on one-dimensional organic nanostructures.

We report on the experimental evidence of tilted polymer nanofiber rotation, using a highly focused linear polarized Gaussian beam. Torque is controlled by varying trapping power or fiber tilt angle. This suggests an alternative strategy to previously reported approaches for the rotation of nano-objects, to test fundamental theoretical aspects. We compare experimental rotation frequencies to calculations based on T-Matrix formalism, which accurately reproduces measured data, thus providing a comprehensive description of trapping and rotation dynamics of the linear nanostructures.

We introduce the integration of organic, polarised light-emitting electrospun nanofibers and lab-on-a-chip microchannel geometries. The alignment and spinning electric field leads to ordered mesoscopic active areas, up to many mm(2), which exhibit polarised light emission and are fully compatible with microlithographies and microfluidics. We utilise the nanofibers demonstrating the photo-excitation of flowing dye chromophores in microchannels. This leads to easy decoupling the excitation and sample emission by polarisation analysers, thus remarkably increasing the imaging signal to background noise ratio.

Organic materials have revolutionized optoelectronics by their processability, flexibility and low cost, with application to light-emitting devices for full-colour screens, solar cells and lasers. Some low-dimensional organic semiconductor structures exhibit properties resembling those of inorganics, such as polarized emission and enhanced electroluminescence. One-dimensional metallic, III-V and II-VI nanostructures have also been the subject of intense investigation as building blocks for nanoelectronics and photonics. Given that one-dimensional polymer nanostructures, such as polymer nanofibres, are compatible with sub-micrometre patterning capability and electromagnetic confinement within subwavelength volumes, they can offer the benefits of organic light sources to nanoscale optics. Here we report on the optical properties of fully conjugated, electrospun polymer nanofibres. We assess their waveguiding performance and emission tuneability in the whole visible range. We demonstrate the enhancement of the fibre forward emission through imprinting periodic nanostructures using room-temperature nanoimprint lithography, and investigate the angular dispersion of differently polarized emitted light.