Surface forces exerted on small liquid droplets on heterogeneous surfaces can be exploited for bottom±up hierarchical assembly of functional nanostructures. We demonstrate here a self-aligned additive printing technique that uses standard inkjet-printing equipment, but is capable of achieving sub-100 nm resolution without any lithographic step. Very small gaps between two printed electrodes are defined uniformly and with high yield by controlling the receding contact-line motion of liquid conductive-ink droplets that are repelled by and flow off the surface of a previously deposited electrode. We illustrate the potential of this technique by fabricating inkjet-printed polymer transistor circuits with sub-100 nm channel lengths that are more than two orders of magnitude faster than previous printed organic-transistor circuits.The application of graphic-arts printing techniques to liquid-based, additive patterning of functional materials promises to provide a new paradigm for manufacturing of large-area, low-cost electronic circuits on flexible substrates. [1,2] However, current resolution achievable with straight inkjet, offset, or gravure printing is limited to 20±50 lm. [3,4] The question of whether printing will be capable of submicrometer-feature definition is a crucial one. It will decide whether printingbased manufacturing will be able to embark on a roadmap of feature-size reductions and corresponding performance enhancements analogous to those of silicon integrated circuits, or whether the challenges of accurately positioning liquid droplets and controlling their flow on the substrate will prevent the use of printing in applications where high switching speeds require submicrometer features. It will also decide whether additive printing will become an important tool for bottom±up nanotechnology, e.g., interfacing with functional nanostructures self-assembled in the liquid phase from smaller building blocks. In principle, printing fulfils many of the material-compatibility requirements for liquid-based self-assembly, but for many systems a key requirement is a patterning resolution of less than 100 nm in order to match the length scale over which supramolecular structure formation can be controlled with high precision. [5,6] Here we demonstrate a novel bottom±up, self-aligned inkjet printing technique that is capable of defining sub-100 nm critical features with two simple additive printing steps using standard inkjet-printing equipment without the need for any lithography or precise relative alignment. The method comprises the steps of a) inkjet printing a first conductive pattern onto the substrate; b) selectively modifying the surface of the first conductive pattern to be of low surface energy without modifying the surface of the substrate; and c) inkjet printing a second conductive pattern that partially overlaps the first conductive pattern, but does not require precise relative alignment. The droplets of the second pattern are repelled by and flow off the low-energy surface of the first pattern and dr...

No abstract

No abstract

A scalable manufacturing process for fabricating active-matrix backplanes on low-cost flexible substrates, a key enabler for electronic-paper displays, is presented. This process is based on solution processing, ink-jet printing, and laser patterning. A multilayer architecture is employed to enable high aperture ratio and array performance. These backplanes were combined with E Ink electrophoretic media to create high-performance displays that have high contrast, are bistable, and can be flexed repeatedly to a radius of curvature of 5 mm