Organic (semi)conducting materials for 3D printed electronic sensing devices

符合各种形状因素的电子设备是将传感和光电技术集成到包装，可穿戴设备和物联网连接对象中的必要条件之一。有机（半）导电材料的进步证明，这类化合物是实现高度符合要求、可持续发展和成本效益高的器件的关键。事实上，有机电子元件的机械性能可以与支撑（软）基板和与设备层压的目标物体的机械性能相匹配。虽然在软性和可打印设备的背景下开发合成和加工策略以优化有机电子化合物是一个蓬勃发展的研究领域，但人们对解决与它们在对象内的单片集成相关的挑战有着浓厚的兴趣。这种集成将消除层压步骤的需要和与基板机械性能相关的限制，导致独立的有机电子设备的自由设计。在这个泛加拿大合作项目中，我们概述了使用有机（半）导电材料制备三维（3D）打印电子传感技术的方法。虽然2021年柔性和印刷电子路线图提到3D打印电子产品的市场规模估计在2025年达到10亿美元，但它也强调这是一个“新兴领域”。有机（半）导电化合物的3D打印研究的稀缺性清楚地表明，在基础知识方面存在空白，需要通过本研究来填补。例如，由商品聚合物和碳纳米材料制成的导电细丝可用于熔融沉积建模。然而，在制备过程中使用卤化溶剂，以及未公开的混合组合物，这些组合物顶部的电导率值在批次之间变化，阻碍了在可持续制备有机电子传感器件的背景下建立可靠的结构-加工-性能关系。为了克服这些挑战，我们将充分利用我们团队成员的有机电子专业知识的协同作用，分别在有机电子还原染料的合成（Morin），先进制造（3D打印）和功能聚合物材料的表征（Laventure）以及软半导体和晶体管传感器的设计（rondeau - gagn<s:1>）。我们的目标是：1)开发一种有机电子半导体溶液和全聚合物导电丝配方的合成方法；2)通过将配方成分与长丝的微观结构以及由此产生的3D打印样品的微观结构相关联，建立结构-加工-性能关系；3)表征样品的电子和机械性能，最终设计和制造电子传感平台。总的来说，我们项目的突破潜力在于将3D打印领域的重点从结构考虑转向功能考虑，即从复杂的被动架构转向具有技术相关内置设备的架构。我们的项目还将有助于培养高素质的科学家，他们在材料化学方面具有独特的多学科技术和专业技能，可以用于创新的职业生涯。

Electronic devices that are compliant to a variety of form factors is one of the sine qua non conditions for the integration of sensing and optoelectronic technologies in packaging, wearables and connected objects for the Internet of Things. Advances in organic (semi)conducting materials prove that this category of compounds stands as a key player to achieve highly conformable, sustainable, and cost-effective devices. Indeed, the mechanical properties of the organic electronics components can be matched to those of the supporting (soft) substrate and of the targeted object to be laminated with the devices. While developing synthetic and processing strategies to optimize organic electronics compounds in the context of soft and printable devices is a blooming area of research, there is a strong interest in tackling the challenges associated with their monolithic integration within an object. Such integration would eliminate the need for the lamination step and the constraints associated with the mechanical properties of the substrate, leading to the freeform design of self-standing organic electronics devices. In this pan-Canadian collaborative project, we outline our approaches towards the use of organic (semi)conducting materials to prepare three-dimension (3D) printed electronic sensing technologies. While the 2021 Flexible and Printed electronics roadmap mentions that the market size for 3D printed electronics is estimated to reach $1 billion in 2025, it also highlights that it is 'a nascent field'. The scarcity of the investigations on the 3D printing of organic (semi)conducting compounds clearly identifies a gap in fundamental knowledge, to be filled by this research. For instance, conductive filaments made from commodity polymers and carbon nanomaterials for fused deposition modeling are commercially available. However, the use of halogenated solvents in their preparation, along with undisclosed blend composition topped by batch-to-batch variations in conductivity values impedes the establishment of reliable structure-processing-property relationships in the context of sustainable preparation of organic electronic sensing devices.To overcome these challenges, we will capitalize on the synergy of the organic electronics expertise of our team members, respectively in synthesis of vat dyes for organic electronics (Morin), in advanced fabrication (3D printing) and characterization of functional polymer materials (Laventure) and soft semiconductors and transistor sensors design (Rondeau-Gagné). Together, we aim to 1) develop a synthetic approach for an organic electronics semi-conducting solution and an all-polymer conducting filament formulations; 2) establish structure-processing-property relationships by correlating the formulation composition with the microstructure of the filament and that of the resulting 3D printed samples and 3) characterize the electronic and mechanical properties of the samples towards, ultimately, the design and fabrication of an electronic sensing platform. Overall, the breakthrough potential of our project lies in shifting the focus of the 3D printing field from structural to functional considerations, i.e. from complex, yet passive architectures, to architectures with technology-relevant built-in devices. Our project will also contribute to train highly qualified scientists with a unique multidisciplinary technical and professional skillset in materials chemistry, which can be leveraged towards innovative careers.