A novel rapid and easy-to-use method for patterning surfaces on large scale is described. Micro-patterns were created by direct contact of trypsin-functionalized poly(dimethylsiloxane) (PDMS) stamps with poly-L-lysine (PLL) layer adsorbed on silicon surface. The catalytic process does not involve ink transfer and thus lateral diffusion is avoided. As a result duplication of the stamp pattern is highly enhanced comparatively to standard microcontact printing procedure where PLL is used as ink and transferred on silicon surface. Patterning was revealed by fluorescence microscopy and atomic force microscopy (AFM). Adsorption on the patterned surfaces of cellulose nanocrystals was investigated as an example of application.

Nanoimprint lithography is a low cost method which produces trillions of nanostructures on a substrate. One application of this technology is patterned magnetic media where a single imprint on a disk can create a masking layer with more than a trillion nanostructures. Several challenges exist to imprinting bit patterned media (BPM) at a density greater than 1Tbit/in2. This technology would allow an extension of hard drive magnetic recording at densities greater than 1Tbit/in2. One such challenge is imprint resist mechanical properties where the imprinted masking layer should be free of thickness variations and resist flop-over. Herein we describe the nanoindentation mechanical properties of several imprint resist systems along with analysis of imprinted features of BPM at densities between 200-482 Gdots/in2.

Zinc oxide is a promising semiconductor film for active devices on flexible substrates, and synthesis routes using nanoparticle inks enable greater variety of applications. We introduce and characterize a two-step transient laser annealing process to create fully densified zinc oxide films from nanoparticle ink precursors. A low temperature sub-millisecond calcining step to remove solvent and organic stabilizing ligands was followed by a high-temperature pulsed laser sintering step to form densified 50-100 nm thin films with resistivities of 10-1 to 10-3 Ω-cm. Film microstructures can be varied between crystalline and amorphous without significant film damage by adjusting the fluence of the high-temperature sintering step. These processes would be compatible with a variety of nanoparticle species, deposition methods, and patterning methods, including roll-to-roll processing paradigms.

Printing of functional materials requires reliable deposition processes. This work describes the development of printing processes for selected functional materials utilizing industrial-type inkjet printheads. A well-controlled printing process with fluids containing the conductive polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is presented, allowing linear printing speeds of up to 0.35 m/s in single-pass, and smallest line width of approximately 40 μm when printing 7 pL drop volumes. In addition reliable processes for producing ZnO-based films, which enable novel applications for electronic and UV-sensitive devices, and for printing of conductive carbon nanotube layers are shown.

Gravure contact printing is the highest volume, large area printing technique known. It is ideally suited for the fabrication of large-area polymer light emitting diode (PLED) based lighting, backlights and displays. Here we show how gravure can be used to fabricate the poly (3,4-ethylene dioxythiophene) : poly(styrene sulfonate) hole injection layer and the light emitting polymer emissive layer in a conventional PLED, as well as the cesium carbonate electron injection layer in an inverted PLED. The performance equals or exceeds that of devices where these layers are deposited by conventional spin-coating.

In this work, we present progress towards device fabrication using purified, semiconducting-enriched SWNT as the base material. Nanotubes were deposited in different densities (low, moderate, and high density) with different gate length of transistors and effect of each parameter has been studied using DC measurements. It is been shown that the nanotube network density plays a significant role in controlling the performance of such devices. By controlling the density of nanotubes in the network, we laid down a road map to predict and enhance the device performance based on their mobility and on/off ratio. From this work the DC analysis of devices characterization shows a mobility more than 90 cm2/V-s and also on/off ratios as high as, 105 have been achieved. We have demonstrated the first density-control technique over the nanotube network as a key point to modify the transistor’s mobility and on/off ratio [1]. When dense network mats of nanotubes were deposited, devices outperformed with higher mobility more than 90 cm2/V-s, enabling a faster switching speed. While relatively low-density mats yielded devices with on/off ratio of more than 105, which makes this technique feasible for low power nanoelectronics. Besides, the effect of various gate lengths have been studied which reveals an interesting trend between the channel length and the mobility.

Electro photography („ laser printing“) has emerged to one of the leading two-dimensional (2D) print technologies during the last decades. However, in contrast to the well-established ink jet process, the examination of three-dimensional (3D) electro photography has just been started. A newly developed non-contact fusing procedure based on click chemistry methodology has been developed to reduce the mechanical as well as thermal stress during the curing. The inorganic SiOx-coating of the toner particles has been modified for the prospective attachment of the cell-growth promoting amino acid sequence Arg-Gly-Asp (RGD) for an improved cell attachment behavior onto the hydrophobic polymeric material.

We present a simple one-step methodology for direct structuring of porous nanomaterials on the micro- and nano-scale. Our technique, direct imprinting of porous substrates (DIPS), relies on the application of a pre-patterned and reusable stamp to directly imprint porous substrates. DIPS is performed at room temperature and pressure in less than one minute, and circumvents the conventional requirement for resist processing and etching procedures. It is shown that arbitrarily shaped patterns and structures can be transferred to porous nanomaterials with a very high (sub-100nm) feature resolution that is primarily limited by the pore dimensions of the substrate material. DIPS is demonstrated on a wide variety of porous nanomaterials including metals, semiconductors, and insulators. Furthermore, DIPS can be utilized to locally modify material properties including pore dimensions, density, dielectric function, and surface roughness. Lastly, example structures fabricated by DIPS are discussed for their relevance to important applications ranging from drug delivery and imaging, to solar energy conversion, and biosensing.

Despite the availability of many high-volume and low-cost manufacturing processes for LED-based lighting applications, relying mainly on fixed patterns such as LED-backlights and RGB-pixelated displays, novel applications, such as “mood lighting” or interior wall displays call for more complicated and shaped LED arrangements. The presented work is based of a novel roll-to-roll (R2R) process to adaptively and cost-efficiently generate LED arrangements on RMPD® substrates.

Inkjet printing of planar and though-hole electrical interconnections is of high importance to the process, as it provides a fully digital way of interconnecting devices electrically, accounting for the actual position of the component and spatially provide different ink film thicknesses.

Xaar’s industrial inkjet printheads are used to dispense defined volumes of 50 pL of a silver nanoparticle ink in order to provide high reliability and good positioning accuracy while main-taining low satellite drop densities. Specific printing strategies are investigated at a print speed of 0.1 m/s to allow for a reliable electrical connection in case of up to 50 μm deep via connections to the buried component.

Due to the low glass-transition nature of the underlying substrates, low sintering tempera-tures are required to preserve the mechanical properties of the substrate. Low temperature oven sintering yielding sufficient conductivity to drive a current of 40 mA will be discussed.