Figure 1. XRD pattern and FTIR spectra of BCN and HCCN. In summary, we have developed a novel high-security photochromic PUF tag based on HCCN nanosheets.

2025/05/0706:37:34 science 1947

Introduction to the results

Tags based on physical non-cloneable function (PUF) have been proven to be some of the most effective anti-counterfeiting strategies. However, developing low-priced, simple-to-manufacturing, easy-to-certify PUF-based anti-counterfeiting labels is still challenging. This article, Associate Professor Chen Xin and Professor Zheng Yuanhui's team published a paper titled "Carbon Nitride Nanosheet-Based Photochromic Physical Unclonable Functions for Anticounterfeiting Applications" in the journal of the "ACS Appl. Nano Mater.", and studied the preparation of photochromic PUF tag by randomly dispersing highly crystalline carbon nitride (HCCN) particles in polyvinyl acetate (PVAc). The color of the photochromic-derived PVAc/HCCN film was used as the first layer of safety, which was verified by the naked eye. The pattern of randomly distributed HCCN particles within the photochromic region (i.e., PUF) is used as the second layer of safety. PUF can be read through any smartphone equipped with a portable objective lens and then automatically verified by computer vision technology.

Graphics and text introduction

Figure 1. (a) XRD pattern and (b) FTIR spectrum of BCN and HCCN. (c) XPS results for investigation and fine scans of (d) C 1s, (e) N1s, and (f) K2p of (c) and HCCN.

Figure 2. Photochromic mechanism and design diagram of nanosheet CN film

Figure 3, (a) Color switching of HCCN base film. From left to right, films with three different mass ratios between PVAc and HCCN represent three photochromic states and their appearance in three different colors. (b) Absorption changes of the film during the first 20 cycles of color conversion. (c) Absorption spectrum of HCCN-Y, HCCN-G and HCCN-B films after ultraviolet irradiation at room temperature.

Figure 4. (a) Unbiased current test after UV irradiation stops. (b) Unpaired electrons and (c) DMPO- • O 2 - and (d) DMPO- • O • OH substances recorded in the dark environment of EPR.

Figure 5. Anti-counterfeiting tag decoding mechanism based on computer vision technology

summary

In short, we have developed a new photochromic PUF tag based on HCCN nanosheets with high security. This photochromic phenomenon is used as the first layer of safety protection and is easily verified by the naked eye. The random distribution of HCCN particles in PVAc films provides a second layer of security and can be authenticated by mobile phones using computer vision technology . The photochromic PUF tags based on HCCN nanosheets presented in this work provide a new optical anti-counterfeiting method, opening up a new application of CN materials .

Literature:

https://doi.org/10.1021/acsanm.2c03055

science

Fractal geometry is a new discipline founded by American mathematician Mandebrot in the mid-1970s. It is ranked alongside the solitary sub theory and chaos theory as the three major theories in nonlinear scientific research. I won't say that it is a mathematics subject for the ti - DayDayNews

Fractal geometry is a new discipline founded by American mathematician Mandebrot in the mid-1970s. It is ranked alongside the solitary sub theory and chaos theory as the three major theories in nonlinear scientific research. I won't say that it is a mathematics subject for the ti

If you are not familiar with fractals, you cannot be considered a scientific cultural person

05/29 1972

Modern science believes that our universe was born 13.8 billion years ago. 13.8 billion years ago, a singularity exploded. The singularity is a point with infinite mass, infinite energy, infinite density, infinite heat, and infinite volume. After this point exploded, the universe - DayDayNews

Modern science believes that our universe was born 13.8 billion years ago. 13.8 billion years ago, a singularity exploded. The singularity is a point with infinite mass, infinite energy, infinite density, infinite heat, and infinite volume. After this point exploded, the universe

Where does the earth take us? Scientists find that the solar system is running with the earth

05/29 1920

Working principle of cutting wires in the middle wire: The electrode wire wound on the wire conveying barrel moves at a certain speed along the rotation direction of the wire conveying barrel. The workpiece installed on the machine tool workbench is formed and moved relative to t - DayDayNews

Working principle of cutting wires in the middle wire: The electrode wire wound on the wire conveying barrel moves at a certain speed along the rotation direction of the wire conveying barrel. The workpiece installed on the machine tool workbench is formed and moved relative to t

How to determine the processing allowance of the middle-travel wire cutting machine

05/29 1863

Image source: Jingchen | Chalmes University of Technology | Yan Strandquist When a star dies, the violent ending will lead to the birth of neutron stars. Neutron stars are the real heavyweight substance in the universe - a teaspoon of celestial bodies that are several kilometers - DayDayNews

Image source: Jingchen | Chalmes University of Technology | Yan Strandquist When a star dies, the violent ending will lead to the birth of neutron stars. Neutron stars are the real heavyweight substance in the universe - a teaspoon of celestial bodies that are several kilometers

Scientists develop new models to reveal the secrets of the powerful power of controlling neutron stars

05/29 1762

American scientists' drones suddenly got lost and entered a huge Mesopotamian city located in now southern Iraq, built on many interconnected islands. This overwhelming discovery belongs to a research team led by archaeologist Emily Hammer, anthropologist at the University of Pen - DayDayNews

American scientists' drones suddenly got lost and entered a huge Mesopotamian city located in now southern Iraq, built on many interconnected islands. This overwhelming discovery belongs to a research team led by archaeologist Emily Hammer, anthropologist at the University of Pen

The world that has been missing for 5,000 years suddenly "swallows" the drone

05/29 1016

The laws of physics tell us that black holes are the end point of life, and any living body will no longer exist when it falls into a black hole. But in fact, black holes are the starting point of life. If there were no black holes, life might not have appeared. - DayDayNews

The laws of physics tell us that black holes are the end point of life, and any living body will no longer exist when it falls into a black hole. But in fact, black holes are the starting point of life. If there were no black holes, life might not have appeared.

See how black holes give birth to life

05/29 1320

Background Description Conventional electrolytes are usually prepared by dissolving salts into solvents (aqueous or non-aqueous) to produce solvated ions as charge carriers. Solvented ions promote ion transfer between electrodes and through interfaces. Furthermore, the decomposit - DayDayNews

Background Description Conventional electrolytes are usually prepared by dissolving salts into solvents (aqueous or non-aqueous) to produce solvated ions as charge carriers. Solvented ions promote ion transfer between electrodes and through interfaces. Furthermore, the decomposit

Exploring the reliability of ultra-wide temperature domain of solvent-free proton electrolytes

05/29 1406

On October 9, the "China Giant Tree Scientific Expedition Team" composed of the Institute of Botany, Chinese Academy of Sciences, Chenshan Center, the National Important Wild Plant Germplasm Resource Library - Shanghai Chenshan Botanical Garden, China Environmental Protection Fou - DayDayNews

On October 9, the "China Giant Tree Scientific Expedition Team" composed of the Institute of Botany, Chinese Academy of Sciences, Chenshan Center, the National Important Wild Plant Germplasm Resource Library - Shanghai Chenshan Botanical Garden, China Environmental Protection Fou

Interview with Xi Zhinong, the initiator of the "Giant Tree Project",: You can feel the different gradients of the tree and the parasitic plants.

05/29 1636

Recently, the Materials Center of the Institute of Modern Physics, Chinese Academy of Sciences and the Institute of Materials of Beijing Institute of Nonferrous Metals have made progress in the research on the mechanism of radiation resistance of vanadium alloys. - DayDayNews

Recently, the Materials Center of the Institute of Modern Physics, Chinese Academy of Sciences and the Institute of Materials of Beijing Institute of Nonferrous Metals have made progress in the research on the mechanism of radiation resistance of vanadium alloys.

Progress in research on the radiation resistance mechanism of vanadium alloy

05/28 1398

Introduction: The "Ten Major Awards" with domineering names are often mistaken for wolfberry. Do you know the difference between them. This is a plant that many people know. There are also many wild people in the mountains in the countryside. In the past, rural children were diso - DayDayNews

Introduction: The "Ten Major Awards" with domineering names are often mistaken for wolfberry. Do you know the difference between them. This is a plant that many people know. There are also many wild people in the mountains in the countryside. In the past, rural children were diso

The "Top Ten Credits" with a domineering name are often mistaken for wolfberries. Do you know the difference between them?

05/28 1747