Jul 13 2020
Chameleons以改变色彩的能力而闻名。根据其体温或情绪，他们的神经系统指导皮肤组织，其中包含纳米晶体以扩展或收缩，改变了纳米晶体反射光线并将爬行动物的皮肤变成颜色的彩虹。
Inspired by this, scientists at the Pritzker School of Molecular Engineering (PME) at the University of Chicago have developed a way to stretch and strain liquid crystals to generate different colors.
通过制作一个充满液晶液滴的聚合物的薄膜，然后操纵它，他们确定了可用于颜色变色的传感系统的基本原理，该系统可用于智能涂料，传感器，甚至可穿戴电子设备。
The research, led by Juan de Pablo, Liew Family Professor of Molecular Engineering, was published July 10 in the journalScience Advances。
使用薄膜拉伸液体
Liquid crystals, which exhibit distinct molecular orientations, are already the basis for many display technologies. But de Pablo and his team were interested in chiral liquid crystals, which have twists and turns and a certain asymmetrical "handedness" -- like right-handedness or left-handedness -- that allows them to have more interesting optical behaviors.
这些晶体也可以形成所谓的"blue phase crystals,"具有液体和晶体的特性，并且在某些情况下可以比液晶本身更好地传输或反射可见光。
The researchers knew that these crystals could potentially be manipulated to produce a wide range of optical effects if stretched or strained, but they also knew that it's not possible to stretch or strain a liquid directly. Instead, they placed tiny liquid crystal droplets into a polymer film.
"That way we could encapsulate chiral liquid crystals and deform them in very specific, highly controlled ways,"德·帕勃罗说。“这使您能够了解他们可以拥有的属性以及它们表现出的行为。”
Creating temperature and strain sensors
By doing this, the researchers found many more different phases -- molecular configurations of the crystals -- than had been known before. These phases produce different colors based on how they are stretched or strained, or even when they undergo temperature changes.
“现在的可能性确实对想象力开放，”德·帕勃罗说。"Imagine using these crystals in a textile that changes color based on your temperature, or changes color where you bend your elbow."
这样的系统也可以用于测量飞机机翼中的应变，或辨别房间或系统内温度的微小变化。
de Pablo说，颜色的变化提供了一种很好的方法来远程测量事物，而无需任何联系。
“您可以看一下设备的颜色，并知道该材料或设备所承受的压力，并根据需要采取纠正措施，”he said.“例如，如果结构承受太大的压力，您可以立即看到颜色改变并将其关闭以修复它。可以穿织物来测量它，然后尝试纠正它。”
Though the researchers manipulated the materials with strain and temperature, there's also the potential to affect them with voltage, magnetic fields, and acoustic fields, he said, which could lead to new kinds of electronic devices made from these crystals.
“既然我们拥有基本的科学来了解这些材料的行为方式，我们可以开始将它们亚博老虎机网登录应用于不同的技术，”亚博网站下载德·帕勃罗说。
Other authors include Monirosadat Sadati and Nader Taheri Qazvini of the University of South Carolina; postdoctoral researchers Jose A. Martinez-Gonzalez and Rui Zhang; graduate student Ye Zhou; alumna Khia Kurtenbach; research scientist Xiao Li; Emre Bukusoglu of Middle East Technical University; Nicholas L. Abbott of Cornell University; and Juan Pablo Hernandez-Ortiz of the Universidad Nacional de Colombia.
Citation:"Prolate and oblate chiral liquid crystal spheroids."Sadati et al,Science Advances。doi：10.1126/sciadv.aba6728
资金：国家科学基金会能源部亚博老虎机网登录
Source:https://pme.uchicago.edu/