Photosynthesis-inspired manufacturing of metal patterns (photobioform)

我们发明了一种新的图案化工艺，该工艺允许在非导电、塑料、柔性基板、涂层或粉末（如聚酰亚胺或PEI（聚醚酰亚胺））上形成金属轨道。该方法在大气压力下使用低成本设备在空气环境中进行。该方法包括将基材简单地浸入氢氧化钾溶液中，然后再浸入金属离子溶液中。第一次浸渍允许酰亚胺环化学结构的打开和钾离子插入到断裂的化学环中。第二次浸渍允许钾离子与电解质溶液的离子交换。可以使用激光或使用光掩模的泛光曝光设备来还原表面金属离子，从而产生金属离子的梯度，然后离子扩散到耗尽区中并到达它们还原的表面。一种温和的给电子剂已被用来加速离子的还原。然后使用这个简单的过程形成一层金属纳米颗粒薄层，其可用于随后的化学镀或用于传感目的。我们的初步可行性研究发表在IEEE纳米技术交易中，已经证明了使用合成剂的概念，其代价是长时间暴露和对基底的损害。我们开始使用一种生物启发材料，从菠菜叶中提取的叶绿素，使用蓝光LED将光化学过程从3小时加速到1分钟。我们希望证明，叶绿素的使用可以实现真正的制造工艺，该工艺可以扩大规模，并充分表征塑料电子产品，PV，电子产品中的模制互连，传感应用，以及用于多材料制造的增材制造。

We have invented a new patterning process, which allows the formation of metal tracks onto non-conductive, plastic, flexible substrates, coating or powder such as polyimide or PEI (polyetherimide). The process takes place in air environment at atmosphere pressure using low cost equipment. The process involves the simple dipping of a substrate into a solution of potassium hydroxide, following by another dipping into a metal ions solution. The first dipping allows the opening of the imide ring chemical structure and insertion of the potassium ions into the broken chemical ring. The second dipping allows the swapping of the potassium ions with the ions of the electrolyte solution. A laser or a flood exposure equipment using a photomask can be used to reduce the surface metal ions resulting in a gradient of metal ions, then the ions diffuse into the depleted zone and reach the surface where they reduce. A mild electron-donating agent has been used to accelerate the reduction of the ions. A thin layer of metal nanoparticles is then formed using this simple process, which can be used for subsequent electroless plating or for sensing purposes. Our preliminary feasibility studies published in IEEE transactions in Nanotechnology have demonstrated the concept using a synthetic agent at the cost of long exposure time and damage to the substrate. We started using a bio-inspired material, chlorophyll extracted from spinach leaves, to speed up the photochemical process from 3 hours to 1 minute exposure using a blue light LED. We wish demonstrate that the use of chlorophyll can enable a truly manufacturing process that can be scaled up, and fully characterised for plastic electronics, PVs, moulded interconnects in electronics, sensing applications, in conjunction with additive manufacturing for multi-material manufacturing.