一群总部位于中国的研究人员开发了一种新的方式，可以为3D印刷零件增色，据说比传统的染色或色素沉着更安全。
The scientists’ approach revolves around a biocompatible ink they’ve developed, which yields parts capable of changing appearance through ‘structural coloration,’ in response to heat or light stimuli. Using their material, the team say it could be possible to produce everything from wearable bio-sensors to more child-safe toys.
“We believe that [our] cholesteric liquid crystal ink can shed light on next-generation environmentally friendly 3D photonic printing,” the team explain in their paper, published in this week’s Proceedings Of The National Academy Of Sciences journal. “The ink maintains a cholesteric liquid crystalline state that gives rise to the structural color.”
克服染色的毒性
在更广泛的世界中，除了3D打印之外，相对众所周知，某些版本的消费产品（例如头发和服装染料）可能会导致用户遭受健康问题的困扰。可持续服装运动小组对你好甚至说，在后者中，“今天使用的许多染料具有致癌性”，尽管臭名昭著的“偶氮染料”在欧盟被禁止使用，但它们通常在其他地方使用。
研究人员对用于染色3D打印丝的颜料感兴趣。尽管用于此目的的添加剂往往因材料而异，并且像许多事情一样，在某些浓度下可能是有毒的，尤其是当它们凝聚时。这就是为什么如此广泛的研究进入诸如食品或皮肤接触“安全”之类的合格零件的部分原因，因为在这些地区可能会进行交叉污染。
That being said, in many cases, the coloration of fused filament fabrication 3D printed parts remains essential to their end-application, whether they be lifelike clinical models or desktop figures. The researchers at上海的福丹大学,Southeast University in Nanjingand theUniversity of Chinese Academy of Sciences因此，已经找到了解决方案，他们现在在自然世界中找到了它。
Specifically, the scientists have tried to replicate an effect known as structural coloration, which is used for everything from camouflage to attracting a mate, by animals such as butterflies and peacocks. In practice, the phenomenon creates the illusion of color via microscopically-structured surfaces, fine enough to interfere with visible light, often without the need for pigmentation to do so.
“当材料被照亮时，一些光源的波长会反映出来，从而创造出我们认为的颜色。”told the South China Morning Post。“在自然界中，这就是蝴蝶和昆虫，变色龙和某些植物的翅膀上没有色素的充满活力和金属色的方式。”
“Structural coloration, based on the physics of color, is more stable and the color will not easily fade.”
A ‘structural coloration’ 3D printing ink
To formulate their novel 3D printing material, the researchers combined gelatin and hydrogel with hydroxypropyl cellulose (HPC) and cholesteric cellulose liquid crystals (CLCs). Using HPC as a ‘building block,’ the team found they were able to develop CLCs capable of creating bright and metallic colors, while the integration of a thermally-responsive hydrogel allowed this process to be ‘triggered’ by UV light.
Aiming to assess their material’s color-shifting capabilities, the scientists then went on to 3D print prototypes of varying shapes on flat surfaces, such as tinfoil and a laboratory bench. In each case, the parts are said to have changed appearance on-cue, thus the team now claim they’re looking into ways of improving on their formula, such as replacing its hydrogels with “naturally-derived alternatives.”
通过这样做，研究人员说，有可能使他们的墨水可食用，从而为其提供新的潜在市场。该团队还调查了使用其材料在弯曲表面上制造零件的可能性。从理论上讲，这可以使建立复杂的部分，例如儿童玩具中的那些部分，出于明显的原因，必须达到某些无毒标准。
Luoran总结说：“预计进一步修改了墨水的配方。”“目前，对象已在平坦的表面上打印。我们希望该技术可以将来适合弯曲的表面，例如苹果，以后的形状不同。”
自然风格的添加剂制造雷电竞充值
The Chinese scientists’ new material may well be unique, but it’s surprising how often the natural world seems to serve as a basis for 3D printing innovation. Just last year, scientists at the美国陆军的夜视实验室managed to develop a unique 3D printed roller, capable of盖章可能使飞蛾看不见的图案进入军事设备。
Researchers atZhejiang University同时，在努力发展的努力方面，已经求助于墨鱼biomimetic cell-like structures具有独特的能量吸收能力。超轻量级，但仍然能够承受自己的变形自身重量的20,000倍，该团队说可以在飞机，装甲，车辆或建筑物的创建中应用此类零件。
还从海洋生物中汲取灵感，科学家台湾国家科技大学提出新的晶格3D打印结构也模仿海胆的形态。使用这些生物的机械稳定和承重形状，那里的团队已经能够建立更有效的无支撑零件。
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特色图像显示在不同的热条件下的3D打印零件更换颜色。图片通过中国南方早晨的图像。
