A system for the synthesis of turbium-doped cobalt chromates for fingerprint recognition

Abstract

A system for the synthesis of turbium-doped cobalt chromate for fingerprint recognition applications, comprising: a sample solution preparation arrangement configured to prepare a homogeneous solution of metal nitrates and fuel; a heating arrangement configured to heat the prepared nitrate solution until combustion is complete; and a grinding unit consisting of a mortar and pestle, designed to grind the product obtained after combustion to obtain a fine powder.

Description

FIELD OF THE INVENTION

[0001] The present disclosure relates to a system for synthesizing terbium-doped cobalt chromate for fingerprint applications. More specifically, the present invention relates to the preparation of phosphorus from terbium-doped cobalt chromate and the subsequent use of this phosphorus for fingerprint recognition applications to evaluate its potential in fingerprint recognition applications. BACKGROUND OF THE INVENTION

[0002] Fingerprints serve as unique, individual identifying features. These features can be divided into three categories, ranging from general ridge patterns to tiny details like sweat pores. When fingers touch surfaces, they leave latent fingerprints of sebum and sweat that are invisible to the naked eye.

[0003] Current photoluminescent materials for latent fingerprint detection face significant challenges: precious metal nanoclusters are prohibitively expensive, fluorescent carbon dots with strong solid-state fluorescence are difficult to synthesize, and existing materials struggle to comprehensively visualize all levels of the fingerprint. Materials with aggregation-induced emission require long reaction times, while conventional techniques such as ninhydrin can only detect limited ridge details, which can be easily reproduced with artificial skin.

[0004] There is a need for advanced visualization materials. Rare earth-doped materials are proving to be a promising solution, offering high stability, low toxicity, narrow emission peaks, and broad applicability for forensic fingerprint recognition.

[0005] In view of the foregoing discussion, the present invention provides a system for synthesizing terbium-doped cobalt chromates for fingerprint applications. The prepared sample is intended to serve as an advanced visualization material and offers promising potential for fingerprint recognition applications. SUMMARY OF THE INVENTION

[0006] The present disclosure relates to a system for synthesizing terbium-doped cobalt chromates for fingerprint applications. This invention introduces a novel turbium (Tb)-doped cobalt chromate (CoTrxCr2-xO4) phosphor material specifically designed for advanced latent fingerprint detection. The material exhibits exceptional capabilities in visualizing fingerprint features at all three levels and offers unprecedented clarity and contrast under ultraviolet (UV) irradiation. By synthesizing a specific composition with x=0.03, the invention provides a stable, high-performance solution that overcomes existing limitations in forensic fingerprint detection technologies.

[0007] The present disclosure is intended to provide a system for synthesizing terbium-doped cobalt chromates for fingerprint applications. The system comprises: a sample solution preparation assembly configured to prepare a homogeneous solution of metal nitrates and fuel; a heating assembly configured to heat the prepared nitrate solution until combustion is complete; and a grinding unit comprising a mortar and pestle and configured to grind the product obtained after combustion is complete to obtain a fine powder.

[0008] An object of the present disclosure is to provide a system for synthesizing terbium-doped cobalt chromates for fingerprint applications.

[0009] Another objective of the present disclosure is to develop a low-cost and versatile photoluminescent material for comprehensive visualization of latent fingerprints across Level I, II, and III ridge features.

[0010] Another object of the present disclosure is to provide a system that synthesizes a phosphor material that maintains consistent performance even under prolonged UV irradiation, heat treatment, and extended storage conditions.

[0011] Another objective of the present disclosure is to provide a high-resolution visualization material that overcomes current technological limitations in fingerprint recognition, and in particular addresses the limitations of existing techniques based on precious metals and carbon dots.

[0012] To further clarify the advantages and features of the present disclosure, a more detailed description of the invention will be given with reference to specific embodiments thereof, which are illustrated in the accompanying drawings. It should be noted that these drawings represent only typical embodiments of the invention and are therefore not to be considered limiting its scope. The invention will be described and explained in additional detail and in greater detail with reference to the accompanying drawings. SHORT DESCRIPTION OF THE FIGURE

[0013] These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout. Where: Fig. 1 shows a block diagram of a system for synthesizing terbium-doped cobalt chromates for fingerprint applications according to an embodiment of the present disclosure.

[0014] Furthermore, those skilled in the art will appreciate that elements in the drawings are shown for convenience and may not necessarily be drawn to scale. For example, the flowcharts illustrate the method by key steps to enhance understanding of aspects of the present disclosure. Furthermore, with respect to device construction, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawing may show only the specific details relevant to understanding embodiments of the present disclosure in order not to clutter the drawings with details that would be readily apparent to those skilled in the art who would benefit from the description herein. DETAILED DESCRIPTION:

[0015] To facilitate an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and described in specific language. It is to be understood, however, that no limitation on the scope of the invention is intended thereby, since such changes and further modifications of the illustrated system and such further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention pertains.

[0016] It will be understood by one skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be limiting thereof.

[0017] References in this specification to "one aspect," "another aspect," or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, occurrences of the phrase "in one embodiment," "in another embodiment," and similar language throughout this specification may or may not all refer to the same embodiment.

[0018] The terms "comprises," "comprising," or other variations thereof are intended to cover non-exclusive inclusion, such that a process or method comprising a list of steps not only includes those steps, but may also include other steps not expressly listed or inherent in such process or method. Likewise, one or more devices or subsystems or elements or structures or components preceded by "comprises...a" does not preclude, without further limitation, the existence of other devices or other subsystems or other elements or other structures or other components or additional devices or additional subsystems or additional elements or additional structures or additional components.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are for illustrative purposes only and should not be considered limiting.

[0020] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0021] Fig. 1 shows a block diagram of a system (100) for synthesizing terbium-doped cobalt chromates for fingerprint applications according to an embodiment of the present disclosure.

[0022] With reference to Fig.1, the system (100) comprises a sample solution preparation assembly (102) configured to prepare a homogeneous solution of metal nitrates and fuel; a heating assembly (104) configured to heat the prepared nitrate solution until combustion is complete; and a grinding unit (106) comprising a mortar and pestle (106a) and configured to grind the product obtained after combustion is complete to obtain a fine powder.

[0023] In one embodiment, the sample solution preparation assembly (102) comprises: a solution preparation unit (102a) comprising a dissolving mechanism (102b) and a magnetic stirrer (102c) connected to a container (102d) in which calculated amounts of cobalt nitrate, rubidium nitrate, and chromium nitrate are dissolved in water; a fuel delivery mechanism (102e) configured to add an appropriate amount of fuel to the container with the nitrate solution, wherein the fuel is completely dissolved in the nitrate solution using a magnetic stirrer; and a transfer mechanism (102f) configured to transfer the solution in the container to a combustion tray (102g).

[0024] In one embodiment, the fuel may contain urea and glucose, and the magnetic stirrer (102c) operates continuously until a homogeneous nitrate solution is produced.

[0025] In one embodiment, the heating arrangement (104) comprises a heating plate (104a) and a temperature control module (104b) connected to the heating plate (104a).

[0026] In one embodiment, the combustion tray (102g) is placed over the heating plate (104a), and the temperature control module (104b) heats the plate (104a) to boil the solution stored in the combustion tray (102g).

[0027] In one embodiment, mortar and pestle (106a) convert the product into a fine powder.

[0028] In one embodiment, the system (100) further comprises a furnace (108) into which the processed fine powder is transported via a conveyor belt mechanism (110).

[0029] In one embodiment, the prepared terbium-doped cobalt chromate powder can be used to develop latent fingerprints.

[0030] The present invention relates to a system for the synthesis of turbium-doped CoTr x Cr 2-x O4 (x=0.03) for the development of latent fingerprints. The system is configured to prepare a precursor solution, burn, and post-treat the prepared phosphor sample. Upon irradiation with ultraviolet (UV) radiation, the prepared phosphor enables the unambiguous identification of structural features of stages 1-3 of latent fingerprints. The developed fingerprints are stable under long-term storage, intense UV irradiation, and heat treatment.

[0031] The materials required to produce terbium-doped cobalt chromate include cobalt nitrate (Co(NO3)2 6H2O), terbium nitrate (Tb(NO3)3 5H2O), chromium nitrate (Cr(NO3)3 9H2O), fuel (e.g., urea, glycine, or citric acid), and distilled water. The required amounts of cobalt nitrate, rubidium nitrate, and chromium nitrate are calculated based on the desired composition. The calculated amount of material is dissolved in distilled water in a beaker. The solution is then stirred with a magnetic stirrer to ensure complete dissolution of the salts. An appropriate amount of fuel (urea and glucose) is added to the nitrate solution. The fuel acts as a reducing agent and assists the combustion process. The magnetic stirrer is then continued to stir until the fuel is completely dissolved and a homogeneous solution is obtained.The homogeneous solution is then added to the precursor solution in a combustion dish or crucible that can withstand high temperatures. The dish is then placed on a hot plate, and the solution is slowly heated until it begins to boil. The solution is heated continuously until it undergoes a vigorous combustion reaction, producing a voluminous, foamy product. This usually occurs when the solvent evaporates and the reaction reaches a critical temperature. Allow the combustion process to complete. This usually results in a fluffy, porous product of metal oxides. After combustion is complete and the prepared product has cooled, the product is ground to a fine powder using a mortar and pestle and then placed in a furnace as the ground powder.

[0032] In an exemplary embodiment, the prepared terbium-doped cobalt chromate fine powder sample is used in a fingerprint recognition application in which a female volunteer provides her fingerprints. First, a clean thumb is lightly pressed against the forehead to absorb natural oils, and then it is dabbed on clean paper to remove excess grease. The thumb is then pressed against various surface materials. To obtain a clear latent fingerprint, CoTr x Cr 2-xO4 (x = 0.03) was applied, followed by gently blowing away excess powder with a lamp. Fingerprint images were taken under natural light using a digital camera with an 18-55 mm lens (black). The aim was to evaluate the effectiveness of the phosphor in detecting latent fingerprints. Comparisons were made between different types of phosphors and different substrate materials to analyze their performance.

[0033] The present invention aims to evaluate the effectiveness of the prepared sample in fingerprint recognition. The efficacy of the phosphor CoTrxCr2-xO4 (x=0.03) in developing latent fingerprints is analyzed in detail, highlighting its superiority over previously reported materials. This synthesized product exhibits exceptional performance in visualizing fingerprints with high clarity and stability, making it a valuable tool for forensic investigations. The fingerprints developed with CoTrxCr2-xO4 (x=0.03) exhibited consistent Level I-III features, including global patterns such as core and ridge flow, local minutiae such as branching and ridge ends, and fine details such as sweat pores and scars.These features remained distinct and well-defined, demonstrating the material's ability to enhance the visibility of complex fingerprint features critical for accurate identification.

[0034] The small particle size of the phosphor allows it to adhere effectively to the grooves of the fingerprint residue, ensuring a clear contrast between grooves and ridges. Pixel intensity profiles generated using ImageJ software confirmed the clarity of the fingerprint patterns, with ridges exhibiting higher intensity values ​​due to greater phosphor accumulation, while grooves showed lower values. This clear distinction enables the detection and analysis of detailed fingerprint features, thus improving the reliability of forensic investigations. In addition, interactive 3D diagrams showed a topographical representation of the fingerprint's ridge patterns, highlighting raised ridges and depressed ridges, contributing to a more comprehensive understanding of the fingerprint structure.

[0035] Compared to other materials such as AlN:Ce,Tb, carbon dots, and amphiphilic silica, the phosphor CoTrxCr2-xO4 (x=0.03) demonstrated superior optical properties, enabling better visualization of fine fingerprint details. Application of the material to various substrates, including glass, aluminum foil, and steel, demonstrated consistent results with clear outlines and detailed features visible under natural light. This versatility makes it highly suitable for real-world forensic scenarios where fingerprints are often found on diverse surfaces.

[0036] The durability and stability of fingerprints developed with CoTrxCr2-xO4 (x=0.03) was remarkable, even under challenging conditions. Aged fingerprints stored for up to 90 days retained their clarity, with minimal deterioration in the intensity values ​​of ridges and grooves, ensuring long-term preservation. Furthermore, fingerprints exposed to UV irradiation for up to 90 minutes retained their structural integrity, highlighting the material's resilience under adverse conditions. These properties demonstrate the phosphor's reliability in preserving fingerprints in cases where they were stored for extended periods or exposed to environmental factors.

[0037] Overall, the CoTrxCr2-xO4 phosphor (x=0.03) represents a significant advance in fingerprint recognition technology. Its ability to clearly and stably highlight detailed fingerprint features and adapt to diverse substrates and environmental conditions makes it a superior alternative to previously reported materials. This innovation improves the accuracy and reliability of fingerprint analysis, making it an invaluable asset for modern forensic applications.

[0038] The drawings and the foregoing description provide examples of embodiments. Those skilled in the art will recognize that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be separated into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of the processes described herein may be changed and are not limited to the manner described herein. Furthermore, the actions of any flowchart need not be implemented in the order shown; nor do all actions necessarily need to be performed. Also, those actions that are not dependent on other actions may be performed in parallel with the other actions. The scope of the embodiments is in no way limited by these specific examples.Numerous variations, whether explicitly stated in the specification or not, such as differences in structure, dimensions, and material use, are possible. The scope of the embodiments is at least as broad as indicated in the following claims.

[0039] Advantages, other benefits, and solutions to problems have been described above with reference to specific embodiments. However, the advantages, benefits, solutions to problems, and any components that may cause an advantage or solution to occur or become more apparent are not to be construed as a critical, required, or essential feature or component of any or all of the claims. REFERENCES 100 A system for the synthesis of terbium-doped cobalt chromates for fingerprints. 102 Sample solution preparation 102a Solution preparation unit 102b Dissolution mechanism 102c magnetic stirrer 102d container 102e Fuel delivery mechanism 102f transmission mechanism 102g cremation bowl 104 radiators 104a hotplate 104b Temperature control module 106 Grinding unit 106a Mortar and Pestle 108 Oven 110 Transfer conveyor mechanism

Claims

[1] A system for synthesizing turbium-doped cobalt chromate for fingerprint recognition applications, comprising: a sample solution preparation assembly configured to prepare a homogeneous solution of metal nitrates and fuel; a heating arrangement configured to heat the prepared nitrate solution until combustion is complete; and a grinding unit consisting of a mortar and pestle designed to grind the product obtained after combustion to obtain a fine powder. [2] The system according to claim 1, wherein the sample solution preparation unit comprises: a solution preparation unit comprising a dissolving mechanism and a magnetic stirrer connected to a container in which calculated amounts of cobalt nitrate, rubidium nitrate, and chromium nitrate are dissolved in water; a fuel delivery mechanism configured to deliver the appropriate amount of fuel into the container containing the nitrate solution, wherein the fuel is completely dissolved in the nitrate solution using a magnetic stirrer; and a transfer mechanism designed to transfer the solution in the container into a combustion tray. [3] System according to claim 1 and 2, wherein the fuel may contain urea and glucose and wherein the operation of the magnetic stirrer is continued until a homogeneous nitrate solution is produced. [4] The system of claim 1, wherein the heating assembly comprises a heating plate and a temperature control module connected to the heating plate. [5] The system of claim 2 and 4, wherein the combustion tray is disposed above the heating plate and the temperature control module heats the plate to boil the solution contained in the combustion tray. [6] System according to claim 1, wherein the mortar and pestle convert the product into a fine powder. [7] The system of claim 1, further comprising a furnace into which the processed fine powder is conveyed via a conveyor belt mechanism. [8] The system of claim 1, wherein the prepared terbium-doped cobalt chromate powder can be used to develop latent fingerprints.

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