PAPIER - Plasma Assisted Printing of Metal Inks with Enhanced Resistivity

向低成本柔性电子产品的转变是本世纪最突出的进步之一：从发光二极管到太阳能电池，再到可穿戴电子产品等印刷生物传感器，印刷电子产品已融入现代生活的方方面面。然而，随着我们朝着越来越低的处理温度发展，以便能够在纸、聚合物甚至皮肤上打印，这项技术正在努力追赶。热沉积技术有其局限性，熔融金属的图案化与负担得起的柔性材料不兼容，包括可再生的环保塑料或纸张。这种不匹配部分是由于金属的高熔点(通常在一千度以上)，这与一系列塑料、纸张或织物材料的变形温度(低得多)形成了鲜明的对比。100-200摄氏度)。目前在印刷电子产品生产中使用的技术是耗时和昂贵的多步骤技术，需要使用有毒化学物质。这些最先进的技术需要将金属薄片/颗粒熔化在一起，导致层与层之间的污染物，从而降低金属的整体导电性。通过一种简单且可扩展的方法在常压和室温下打印金属涂层是不断增长的印刷电子市场尚未满足的需求。除了少数例外，导电油墨材料是金属纳米颗粒的分散体。然而，这些油墨需要在限制其广泛使用的温度下进行烧结(摄氏50度)。此外，纳米颗粒经常堵塞喷墨打印机喷嘴的涂层。金属有机分解(MOD)油墨提供了纳米颗粒油墨的替代方案。这项技术的发展可能会给许多不同的科学领域带来深远的好处。这个纸质项目的重点是有机金属化合物，而不是纳米颗粒，用于大气压等离子体辅助印刷过程中的MOD油墨。MOD油墨与等离子辅助印刷的独特和史无前例的结合将使我们能够在常压和室温下在各种基材上大规模生产复杂的有图案的金属表面。详尽的表面表征将使人们深入了解MOD油墨的印刷机理，并促进其他新功能金属薄膜的开发。典型的油墨配方是通过大规模筛选和故障排除来优化的，这意味着没有专门针对所涉及的基础化学的全面研究。因此，迫切需要进一步探索这一领域。名单上的国际合作者避免使用热激活的能力对该项目的成功至关重要，突出了合成卓越和等离子沉积的互补和协同专业知识。该项目旨在提高现有印刷技术的性能。这将为目前以银为基础的工业方法提供一种可调的替代方法，这些方法的激活温度太高，无法打印到许多材料上。铝和铜都成本低，富含稀土，而且传导效率与银一样高。我们将在金属的等离子打印中使用我们的小分子，这将与现代的低温沉积技术兼容。为了获得使用打印技术制造设备的好处，将生产在室温下可以转变的油墨(提供与低成本柔性材料的兼容性)。该项目将创建一个由铝和铜制成的新型高性能墨水库，这些墨水可以在低成本的柔性材料上打印并在空气中烧结，以便集成到电子设备中。

The move toward low-cost flexible electronics is one of the standout advancements of this century: printed electronics are integrated into every part of modern-day life, from light-emitting diodes, to solar cells and printed biosensors such as wearable electronics. However, as we move toward ever-lower processing temperatures in order to enable printing on paper, polymers or even skin, the technology is struggling to catch up. Thermal deposition techniques have their limitations, and the patterning of molten metals is incompatible with affordable flexible materials, including renewable eco-friendly plastics or paper. This mismatch is due, in part, to the high melting point of metals (often over a thousand degrees) which is in stark contrast to the deformation temperature of a range of plastic, paper or fabric materials (considerably lower approx. 100 - 200 degrees Celsius). Techniques currently used in the production of printed electronics are time-consuming and expensive multi step-techniques that require the use of toxic chemicals. These state-of-the-art techniques require metal flakes/particles to be 'melted' together, resulting in contaminants between layers, which reduce overall conductivity of the metal.The atmospheric-pressure and room-temperature printing of metallic coatings from a simple and scalable method is an unmet need of the ever-growing printed electronics market. With a few exceptions, conductive ink materials are dispersions of metallic nanoparticles. Nevertheless, these inks require sintering at temperatures which limits their widespread use (> 50 degrees celcius). In addition, the nanoparticles often clog inkjet printer nozzles upon coating. Metal-organic decomposition (MOD) inks provide an alternative to nanoparticle inks. The development of this technology could have profound benefits for many different scientific fields. This PAPIER project focusses on organometallic compounds, as opposed to nanoparticles, for use in MOD inks in an atmospheric-pressure plasma assisted printing process. The unique and unprecedented combination of MOD inks with plasma assisted printing will enable intricate patterned metallic surfaces to be produced on a large scale and on a range of substrates at atmospheric pressure and room temperature. Exhaustive surface characterizations will allow a deep understanding of mechanisms involved in the printing of MOD inks and promote the elaboration of other new functional metallic thin films.Typically ink formulations are optimized using mass screening and elimination of failures which means that there are no comprehensive studies dedicated to the fundamental chemistry involved. Consequently, there is an urgent need to explore this area further. The ability of the international collaborators at the LIST to avoid using thermal activation is crucial to the success of this project, highlighting the complementary and synergetic expertise of synthetic excellence and plasma deposition. This project aims to improve the performance of existing printing technologies. These would provide a tuneable alternative to the current industrial methods based on silver whose activation temperatures are too high for printing onto many materials.Both aluminium and copper are low cost, earth abundant, and conduct with as much effectiveness as silver. We will use our small molecules in the plasma printing of metals, which will be compatible with modern lower temperature deposition techniques. To reap the benefits of using printing techniques for device fabrication, inks that will transform at room temperatures (affording compatibility with low cost flexible materials) will be produced. This project will create a library of novel highly performing inks from aluminium and copper which can be printed and sintered in air on low cost flexible materials for incorporation into electronic devices.