分通道拼接潜像光栅防伪方法

目的根据潜像信息嵌入的通道不同,产生的隐藏和提取效果会存在差异的原理,研究一种拼接潜像分通道嵌入的相位调制光栅防伪技术。方法将蝴蝶形态的潜像分割成对称的左右2个部分,在CMYK 4个通道两两成组分别嵌入潜像的左侧部分和右侧部分,无缝对接形成完整的防伪信息;对整体潜像隐藏性进行主客观评价,证明K版的不适用性;设计与不同加网线数宿主图像所对应的数字光栅,提取隐藏信息,潜像显著性好。结果分通道拼接潜像法有良好的防伪效果,其中潜像的两部分分别位于C版和M版时其隐蔽性与提取显著性均最佳,K版不适合作为防伪信息的嵌入通道,宿主图像的加网线数对拼接潜像的防伪效果无明显影响。结论该研究成果实现了潜像的双通道参与,提高了工艺的复杂性,增强了仿伪效果,为相位调制潜像防伪技术提供了新的理论。     

光栅隐形潜像防伪技术研究

目的研究借助光栅材料实现高档印品的防伪技术。方法结合光栅材料特殊的光学特性和半色调图像加网技术,提出隐形潜像防伪技术,采用最小阈值矩阵的原理,实现变角度加网防伪技术。详细论述每种防伪技术的原理,分别使用Photoshop和Matlab编程模拟来实现这些算法。结果以EPSON Stylus Pro7880C为图像输出设备,在隐形潜像防伪技术中,当光栅片线条角度与印刷品呈45°或135°时,可以清晰看到隐藏的潜像信息;在变角度加网中,使用对应光栅在特定角度21.14°条件下叠加在含水印图像上,清楚地观察到了防伪信息。结论通过实验,表明光栅隐形潜像防伪技术在印品防伪中具有较好的应用效果。     

Laser Generation of Sub-Micrometer Wrinkles in a Chalcogenide Glass Film as Physical Unclonable Functions

Laser interaction with solids is routinely used for functionalizing materials' surfaces. In most cases, the generation of patterns/structures is the key feature to endow materials with specific properties like hardening, superhydrophobicity, plasmonic color-enhancement, or dedicated functions like anti-counterfeiting tags. A way to generate random patterns, by means of generation of wrinkles on surfaces resulting from laser melting of amorphous Ge-based chalcogenide thin films, is presented. These patterns, similar to fingerprints, are modulations of the surface height by a few tens of nanometers with a sub-micrometer periodicity. It is shown that the patterns' spatial frequency depends on the melted layer thickness, which can be tuned by varying the impinging laser fluence. The randomness of these patterns makes them an excellent candidate for the generation of physical unclonable function tags (PUF-tags) for anti-counterfeiting applications. Two specific ways are tested to identify the obtained PUF-tag: cross-correlation procedure or using a neural network. In both cases, it is demonstrated that the PUF-tag can be compared to a reference image (PUF-key) and identified with a high recognition ratio on most real application conditions. This paves the way to straightforward non-deterministic PUF-tag generation dedicated to small sensitive parts such as, for example, electronic devices/components, jewelry, or watchmak.     

Identification of recently handled materials by analysis of latent human fingerprints using infrared spectromicroscopy

Analysis of fingerprints has predominantly focused on matching the pattern of ridges to a specific person as a form of identification. The present work focuses on identifying extrinsic materials that are left within a person's fingerprint after recent handling of such materials. Specifically, we employed infrared spectromicroscopy to locate and positively identify microscopic particles from a mixture of common materials in the latent human fingerprints of volunteer subjects. We were able to find and correctly identify all test substances based on their unique infrared spectral signatures. Spectral imaging is demonstrated as a method for automating recognition of specific substances in a fingerprint. We also demonstrate the use of attenuated total reflectance (ATR) and synchrotron-based infrared spectromicroscopy for obtaining high-quality spectra from particles that were too thick or too small, respectively, for reflection/absorption measurements. We believe the application of this rapid, nondestructive analytical technique to the forensic study of latent human fingerprints has the potential to add a new layer of information available to investigators. Using fingerprints to not only identify who was present at a crime scene, but also to link who was handling key materials, will be a powerful investigative tool.     

分通道相位调制潜像法防伪效果的评价

目的以图像半色调加网原理为理论基础,运用相位调制潜像技术实现一种光栅防伪方法。方法设计原图与潜像,对其设置加网参数进行数字加网,在C,M,Y,K通道分别嵌入潜像作为防伪母版,根据加网线数的不同,设计具有对应周期的数字光栅,而后与防伪母版进行适当角度覆合完成防伪信息的提取。用加权信噪比(WSNR)和彩色图像结构相似度法(CISI),分别评价各通道潜像的隐蔽性及信息提取的差异。结果隐藏信息的隐蔽性好,隐藏信息提取再现清晰。结论该防伪方法对于图像加网线数无明显选择性,而通道对于防伪效果有明显影响。K通道中的潜像隐蔽性最差,不适合作为防伪母版。M和C通道中潜像的提取效果最好,是该防伪方法的适用通道。     

多色长余辉材料的发光性质及动态防伪应用

发光防伪具有可视性强、设计简便的特点, 是众多防伪技术中常用的方法。传统防伪材料存在发光颜色单一、防伪图案和颜色静态的缺点, 易于模仿, 亟需开发可实现动态、可靠防伪性能的发光材料。本工作采用水热法制备了铬掺杂镓锗酸锌多色长余辉材料, 并对其余辉性能和动态防伪应用进行研究。实验结果表明: 通过改变镓锗比, 可以调节蓝绿光和红光区的发射强度, 实现发光颜色的可调。该系列样品在波长为254和365 nm的紫外光激发下分别呈现白色和红色, 发光颜色具有多模态发光特征。此外该系列样品具有多色的余辉发光, 不同颜色的衰减速率不同, 可以实现余辉颜色随时间发生动态变化的效果。据此设计成的防伪图案, 发光颜色在时间维度上具有动态变化特性, 可显著提高防伪安全性, 表明所制备的铬掺杂镓锗酸锌多色长余辉材料在动态防伪领域有重要的应用前景。     

雪莲果皮衍生多模式碳量子点的制备及其防伪应用

以生物质废弃物雪莲果皮为碳源,乙二胺为氮源,采用一步水热法制备蓝色荧光氮掺杂碳量子点（N-CQDs）,并探索其在防伪中的应用。实验结果表明：N-CQDs为球形形貌,平均粒径约为1.88 nm;N-CQDs具有类石墨烯结构,表面富含氨基、羧基等官能团;N-CQDs的荧光对Fe3+及pH值具有响应性。以PAA为基质,将N-CQDs制备成丝网油墨,印制的图案在自然光下隐形,在紫外光下显示出蓝色荧光图案,移除紫外光后,呈现绿色磷光图案。此外,在图案上喷涂Fe3+溶液或碱液,其荧光被明显淬灭。基于响应性荧光碳量子点的防伪图案可实现静态、动态两种模式的信息存储,信息安全性与防伪等级更高。     

Chiroptical Nanocellulose Bio-Labels for Independent Multi-Channel Optical Encryption

Advanced multiplexing optical labels with multiple information channels provide a powerful strategy for large-capacity and high-security information encryption. However, current optical labels face challenges of difficulty to realize independent multi-channel encryption, cumbersome design, and environmental pollution. Herein, multiplexing chiroptical bio-labels integrating with multiple optical elements, including structural color, photoluminescence (PL), circular polarized light activity, humidity-responsible color, and micro/nano physical patterns, are constructed in complex design based on host-guest self-assembly of cellulose nanocrystals and bio-gold nanoclusters. The thin nanocellulose labels exhibit tunable circular polarized structural color crossover the entire visible wavelength and circularly polarized PL with the highest-recorded dissymmetry factor up to 1.05 due to the well-ordered chiral organization of templated gold nanoclusters. Most importantly, these elements can independently encode customized anti-counterfeiting information to achieve five independent channels of high-level anti-counterfeiting, which are rarely achieved in traditional materials and design counterparts. Considering the exceptional seamless integration of five independent encryption channels and the recyclable features of labels, the bio-labels have great potential for the next generation anti-counterfeiting materials technology.     

基于塑料薄膜三色油墨的多通道烧蚀技术

使用Q-switched Nd:YAG激光对普通塑料薄膜上多层彩色油墨进行了激光烧蚀,从而产生了全触觉多色图像。研究表明这种方法产生的图像是具有防伪功能的。     

Line-scanning Raman imaging spectroscopy for detection of fingerprints

Fingerprints are the best form of personal identification for criminal investigation purposes. We present a line-scanning Raman imaging system and use it to detect fingerprints composed of β-carotene and fish oil on different substrates. Although the line-scanning Raman system has been used to map the distribution of materials such as polystyrene spheres and minerals within geological samples, this is the first time to our knowledge that the method is used in imaging fingerprints. Two Raman peaks of β-carotene (501.2, 510.3 nm) are detected and the results demonstrate that both peaks can generate excellent images with little difference between them. The system operates at a spectra resolution of about 0.4 nm and can detect β-carotene signals in petroleum ether solution with the limit of detection of 3.4×10(-9) mol/L. The results show that the line-scanning Raman imaging spectroscopy we have built has a high accuracy and can be used in the detection of latent fingerprints in the future.     

基于NFC标签的防伪包装和产品信息查询系统

目的 为了更新传统的包装防伪方式,使消费者快速简洁地查询产品信息,提高产品包装的防伪性能,设计基于NFC标签的防伪包装和产品信息查询系统.方法 利用在Android Studio平台开发的应用程序来实现产品的防伪验证以及产品的信息展示功能.系统设计完成后,利用智能手机端的边界值法对NFC防伪标签的识别距离、信息写入过程以及防伪验证过程进行测试.结果 智能终端对于防伪标签的识别速度可以达到"即触即识",智能终端也可以正常使用该系统,并进行产品的防伪验证和产品信息的展示.结论 系统测试表明,该智能终端提高了防伪识别的便利性,增强了产品与消费者的互动性.     

A Dual‐Organic‐Transistor‐Based Tactile‐Perception System with Signal‐Processing Functionality

Organic‐device‐based tactile‐perception systems can open up new opportunities for the next generation of intelligent products. To meet the critical requirements of artificial perception systems, the efficient construction of organic smart elements with integrated sensing and signal processing functionalities is highly desired, but remains a challenge. This study presents a dual‐organic‐transistor‐based tactile‐perception element (DOT‐TPE) with biomimetic functionality by the construction of organic synaptic transistors with integrated sensing transistors. The unique geometry of the DOT‐TPE permits instantaneous sensing of pressure stimuli and synapse‐like processing of an electric signal in a single element. More importantly, these organic‐transistor‐based tactile‐perception elements can be built into arrays to serve as bionic tactile‐perception systems. The combined biomimetic functionality of tactile‐perception systems, together with their promising features of flexibility and large‐area fabrication, makes this work represent a step forward toward novel e‐skin devices for artificial intelligence.     

信息技术在印刷包装防伪上的应用研究进展

目的综述了信息技术在印刷包装防伪上的应用研究进展。方法根据现有文献介绍信息技术在印刷包装防伪上的应用研究进展,重点介绍与智能标签、网络通信技术、数字图像处理技术结合的印刷包装防伪机理与应用案例;分析无线射频识别系统与防伪结合的应用研究;然后介绍移动互联网、通信技术在印刷包装防伪中的应用研究;最后介绍基于图像处理技术的印刷包装防伪应用,拓展信息技术在印刷包装防伪上的应用领域。结果随着现代科技的高速发展、市场的需求和人们防伪意识的增强,防伪技术的改进成为必然的选择。与印刷包装结合的新型防伪技术也将不断朝着智能化、大众化前进。结论随着高端智能信息技术的快速发展,信息防伪的应用潜力巨大,信息防伪在印刷包装上的应用前景非常可观。     

Tactile Chemomechanical Transduction Based on an Elastic Microstructured Array to Enhance the Sensitivity of Portable Biosensors

Tactile sensors capable of perceiving biophysical signals such as force, pressure, or strain have attracted extensive interest for versatile applications in electronic skin, noninvasive healthcare, and biomimetic prostheses. Despite these great achievements, they are still incapable of detecting bio/chemical signals that provide even more meaningful and precise health information due to the lack of efficient transduction principles. Herein, a tactile chemomechanical transduction strategy that enables the tactile sensor to perceive bio/chemical signals is proposed. In this methodology, pyramidal tactile sensors are linked with biomarker‐induced gas‐producing reactions, which transduce biomarker signals to electrical signals in real time. The method is advantageous as it enhances electrical signals by more than tenfold based on a triple‐step signal amplification strategy, as compared to traditional electrical biosensors. It also constitutes a portable and general platform capable of quantifying a wide spectrum of targets including carcinoembryonic antigen, interferon‐γ, and adenosine. Such tactile chemomechanical transduction would greatly broaden the application of tactile sensors toward bio/chemical signals perception which can be used in ultrasensitive portable biosensors and chemical‐responsive chemomechanical systems.     

稀土上转换荧光材料的多模态发光调控及包装防伪应用

单一荧光模态稀土上转换荧光纳米材料存在防伪应用效果不佳的问题,对其发光模态进行调控,可实现对信息的多维度隐藏,提高防伪信息的复制难度,提升防伪应用效果,从而满足多场景的商品包装防伪需求。综述了近年来通过基质调节、核壳组装与复合异质荧光材料,实现稀土上转换荧光材料的多模态发光调控及防伪应用的研究进展,总结了推进该技术实际应用面临的挑战,提出了未来可能的发展方向。     

A Dual-Responsive Artificial Skin for Tactile and Touchless Interfaces

The progress from intelligent interactions and supplemented/augmented reality requires artificial skins to shift from the single-functional tactile paradigm. Dual-responsive sensors that can both detect pre-contact proximal events and tactile pressure levels enrich the perception dimensions and deliver additional cognitive information. Previous dual-responsive sensors show very limited utilizations only in proximity perception or approaching switches. Whereas, the approaching inputs from the environment should be able to convey more valuable messages. Herein, a flexible iontronic dual-responsive artificial skin is present. The artificial skin is sensitive to external object's applied pressure as well as its approaching, and can elicit information of target material categories encoded in the proximal inputs. Versatile applications are then demonstrated. Dual-mode human–machine interfaces are developed based on the devices, including a manipulation of virtual game characters, navigation and zooming in of electronic maps, and scrolling through electronic documents. More importantly, the proof-of-concept application of an entirely touchless material classification system is demonstrated. Three types of materials (metals, polymers, and human skins) are classified and predicted accurately. These features of the artificial skin make it highly promising for next-generation smart engineered electronics.     

基于周期无穷大纵向莫尔条纹的半色调防伪技术研究

目的通过分析莫尔条纹的种类及产生原理,以纵向莫尔条纹效应和半色调加网图像的信息隐藏为理论基础,研究一种半色调图像防伪方法。方法首先对周期无穷大的纵向莫尔条纹的特性及半色调加网图像的网点排列特性进行了分析,结合半色调图像加网参数,得到纵向莫尔条纹参数与数字加网参数之间的匹配关系;再根据各参数之间的关系对半色调加网图像的部分网点进行调整,实现了隐藏信息的嵌入;最后依据上面各参数关系制作数字光栅,对加入防伪信息的半色调图像进行检测,完成了防伪。结果该防伪技术中隐藏信息的隐秘性好,隐藏信息检测再现清晰,防伪效果较好。结论提出了一种半色调图像防伪新方法。     

时空双通道机器人电触觉临场感再现技术研究

时空双通道机器人电触觉临场感再现将时间通道的刺激电流控制信号和空间通道的触觉信息合成为音波文件,经计算机声卡播放后输出的双声道音波信号分别对应时空两个通道的控制信号,信号经进一步处理后提供触觉再现所需的刺激电流并选通相应触点。该技术对于消除电触觉突发刺痛感和改善时间适应性具有重要价值。     

基于振动触觉感知研究的头戴预警设备开发设计

目的 在预警场景下应用振动触觉传递警报信号以弥补受损的感觉通道,探索头戴振动设备的合理形式,从而为头戴振动设备的工业设计提供指导.方法 围绕空间分布位置、时间和振动参数设置实验,研究振动触觉的特征,提出一种振动触觉系统.在实验一中,对头部进行触觉感知性测量以比较不同位置的灵敏性,确定振动作用于头部的适宜部位.在实验二中,组合不同的时间模式以及强弱程度形成7种振动模式,通过比较得出适于传达警报信息的触觉模式.基于实验结论,设计出一款应用于建筑工地场景下的工程预警头盔.结果 前额无毛区域与颞部中央区域感受性最灵敏;时间间隔短、强度高的振动模式更适于传达警报信息.结论 感知实验的结论为振动组件的布置和振动警报模式的参数设定提供了依据,并有效地被运用于针对具体场景的头戴设备设计中.     

An Artificial Sensory Neuron with Tactile Perceptual Learning

Sensory neurons within skin form an interface between the external physical reality and the inner tactile perception. This interface enables sensory information to be organized identified, and interpreted through perceptual learning—the process whereby the sensing abilities improve through experience. Here, an artificial sensory neuron that can integrate and differentiate the spatiotemporal features of touched patterns for recognition is shown. The system comprises sensing, transmitting, and processing components that are parallel to those found in a sensory neuron. A resistive pressure sensor converts pressure stimuli into electric signals, which are transmitted to a synaptic transistor through interfacial ionic/electronic coupling via a soft ionic conductor. Furthermore, the recognition error rate can be dramatically decreased from 44% to 0.4% by integrating with the machine learning method. This work represents a step toward the design and use of neuromorphic electronic skin with artificial intelligence for robotics and prosthetics.