Photosynthesis-inspired manufacturing of metal patterns (photobioform)

我们发明了一种新的图案工艺，可以在非导电、塑料、柔性基材、涂层或粉末（如聚酰亚胺或PEI）上形成金属轨迹。该工艺在常压下的空气环境中使用低成本设备进行。该过程包括简单地将衬底浸入氢氧化钾溶液中，然后将另一个浸入金属离子溶液中。第一次浸渍可以打开亚胺环的化学结构，并将钾离子插入断裂的化学环中。第二次浸渍允许钾离子与电解质溶液中的离子交换。使用光掩膜的激光或洪水曝光设备可用于减少表面金属离子，导致金属离子梯度，然后离子扩散到耗尽区并到达表面，在那里它们减少。用一种温和的给电子剂来加速离子的还原。然后使用这个简单的过程形成一层薄薄的金属纳米颗粒，可用于后续的化学镀或用于传感目的。我们发表在IEEE transactions in Nanotechnology上的初步可行性研究已经证明了使用合成剂的概念，但代价是长时间的暴露和对基板的破坏。我们开始使用一种生物启发材料，从菠菜叶中提取叶绿素，利用蓝光LED将光化学过程从3小时缩短到1分钟。我们希望证明叶绿素的使用可以实现真正的制造过程，可以扩大规模，并充分表征塑料电子，pv，电子中的模塑互连，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.