Polyacrylonitrile (PAN) was printed into a nanostructured carbon nanopillar arrays using a quick, simple, and highly efficient method called spin-on nanoprinting (SNAP). The mold used to print PAN nanostructures could easily be reproduced via printing an inverse replica of carbon nanopillar arrays. The as-printed carbon nanopillar arrays were further prepared as supercapacitor electrodes. As a result, these nanostructured carbon electrodes display an order of magnitude enhancement in specific capacitance compared to non-nanostructured carbon electrodes.

Wrinkle-less graphene films are obtained through roll-to-roll microwave plasma chemical vapor deposition by using flexible copper/polyimide (Cu/PI) webs. Raman spectra suggests that the average domain size of the obtained graphene on the flexible Cu/PI is almost the same compared to the graphene on a Cu web that includes wrinkles. Also, by utilizing the flexible Cu/PI webs, the compressive strains decreased. The sheet resistances of graphene deposited on the Cu/PI are (1∼5)×104Ω, which is two orders of magnitude lower than those of graphene deposited on the Cu webs. Our results suggest that the controlling the expansion of web material an important technology to improve graphene transparent conductive properties.

Inkjet printing of various nanoparticle inks, made from silver or copper nanoparticles, and its transformation into solid functional patterns is of high interest in the field of printed electronics. Liquid materials can be deposited as defined patterns in selected areas with micrometer precision. To convert these printed liquid films, consisting of solvents, additives and nanoparticles, into solid functional patterns a post-treatment is required. To this date, many investigations report on various sintering techniques to achieve e.g. high conductivity from the printed conductive materials.

Direct thermal sintering (via furnace or hotplate) requires high temperatures, which makes it not suitable for sensitive polymeric substrates. The novel method of intense pulsed light (IPL) sintering opens the window of opportunity to convert liquid or dried metal layers into solid functional layers within milliseconds without damaging the thermally fragile polymeric substrate.

In this work we present and analyze the application of the IPL sintering on inkjet printed silver patterns on various flexible substrates, like Poly(ethylene naphthalate) (PEN), Poly(ethylene terephthalate) (PET), Polyimide (PI) foils and paper.

A high dependency of the electrical and structural performance of the printed silver layers on the base substrate was observed when flashing with the IPL technique. Flashing parameters were varied and the resulting sheet resistance is presented.

With the analytical comparison of optical and electrical results, the flashing settings could be adapted to achieve highly conductive inkjet printed silver patterns on flexible substrates, when compared to other thermal sintering techniques. Furthermore the first integration of this post treatment methodology into semi-industrial roll-2-roll processing was successfully performed and will be demonstrated.

P3HT: PCBM nanoparticle based inks were fabricated using the miniemulsion technique [1]. The nanoparticles were characterized for their size using a quasi-elastic light scattering technique. The average diameter of P3HT:PCBM nanoparticles was found to be 52nm. The blending of the P3HT and the PCBM was tested using UV-Vis absorbance and fluorescence spectroscopy – it was found that the blend ratio of the nanoparticle can be controlled by varying the individual concentrations of the P3HT and PCBM in chloroform ("the oil phase") of the miniemulsions. Finally the P3HT:PCBM nanoparticle inks were inkjet printed onto PEDOT:PSS coated ITO substrates to form the active layer of the organic photovoltaic cell. Aluminum cathodes were evaporated onto the printed nanoparticle active layer film to form functioning OPVs. The best power conversion efficiency for one of these devices was 0.07%.

We report the implementation of an automated reel-to-reel fluidic self-assembly system based on surface-tension driven self-assembly for macroelectronics application. The reported system incorporates precisely controlled and automated agitation, web moving, component recycling, and dispensing system. The system enables continuous parallel assembly of semiconductor chips at a high rate (15,000 chips per hour using 2.5 cm wide web) and assembly yield (>99%) under optimal condition. In principle, scaling to any throughput should be possible considering the parallel nature of self-assembly. The process overcomes the limitations on area and throughput of prior methods. It provides a new platform for macroelectronics to enable the integration of microscopic high performance inorganic semiconductors on flexible substrates with any desired location, pitch, and integration density. As an example we demonstrate the fabrication of a solid state area lighting module.