Method for manifesting metal surface hidden fingerprints through chemical sedimentation

A metal surface and latent fingerprint technology, which is applied in the field of fingerprint identification, can solve the problems of unrealistic fingerprint detection, fingerprints left for a long time, and limited information extraction, etc., and achieve the effect of clear fingerprint texture details, low cost and high efficiency

Inactive Publication Date: 2013-10-23
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional latent fingerprint display method has many deficiencies, such as not being sensitive enough, not accurate enough, not clear enough, and limited in extracting information.
At the crime scene, the fingerprints left by the suspects are ever-changing, and the detection of some of them cannot be realized by existing technical methods; hard to show

Method used

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  • Method for manifesting metal surface hidden fingerprints through chemical sedimentation
  • Method for manifesting metal surface hidden fingerprints through chemical sedimentation
  • Method for manifesting metal surface hidden fingerprints through chemical sedimentation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] A new method for displaying latent fingerprints on more active metal objects. Taking Zn metal objects as an example, for smaller or easy-to-cut objects, the immersion solution method can be used. The specific operation has the following steps:

[0036] 1) Use copper sulfate pentahydrate and ultrapure water as raw materials to prepare copper sulfate mother liquor.

[0037] 2) Weigh 12.484g of copper sulfate pentahydrate with an electronic analytical balance, put it in a 100ml volumetric flask, add ultrapure water to 100ml, and mix well. spare.

[0038] 3) Take the mother solution and dilute it according to the size of the fingerprint object. For sheet metal or thin substrates, how much solution to take is based on: the volume of the mother solution taken / the area of ​​the object = 45μl / ㎝ 2 .

[0039] 4) Object area: 1.0㎝×1.0㎝=1.0㎝ 2 . According to the above formula, the volume of copper sulfate required is about 45μl / ㎝ 2 ×1.0㎝ 2 = 45 μl.

[0040] 5) Take a 10ml c...

Embodiment 2

[0048] Taking the Mg metal object as an example, for small or easy-to-cut objects, the immersion solution method can be used. The specific operation has the following steps:

[0049] 1) Use copper sulfate pentahydrate and ultrapure water as raw materials to prepare copper sulfate mother liquor.

[0050] 2) Weigh 12.484g of copper sulfate pentahydrate with an electronic analytical balance, put it in a 100ml volumetric flask, add ultrapure water to 100ml, and mix well. spare.

[0051] 3) Take the mother solution and dilute it according to the size of the fingerprint object. For sheet metal or thin substrates, how much solution to take is based on: the volume of the mother solution taken / the area of ​​the object = 40μl / ㎝ 2 .

[0052] 4) Object area: 0.9㎝×1.6㎝=1.4㎝ 2 '. According to the above formula, the volume of copper sulfate required is about 40μl / ㎝ 2 ×1.4㎝ 2 =56 μl.

[0053] 5) Take a 10ml clean beaker, add 56μl of the prepared copper sulfate mother solution with a p...

Embodiment 3

[0060] Taking ordinary carbon steel objects as an example, for small or easy-to-cut objects, the immersion solution method can be used. The specific operation has the following steps:

[0061] 1) Use copper sulfate pentahydrate and ultrapure water as raw materials to prepare copper sulfate mother liquor.

[0062] 2) Weigh 12.484g of copper sulfate pentahydrate with an electronic analytical balance, put it in a 100ml volumetric flask, add ultrapure water to 100ml, and mix well. spare.

[0063] 3) Take the mother solution and dilute it according to the size of the fingerprint object. For flake metal or thin substrates, the amount of solution to be taken is based on: the volume of the mother solution taken / the area of ​​the object = 16μl / ㎝ 2 .

[0064] 4) Object area: 2.0㎝×1.5㎝=3.0㎝ 2 '. According to the above formula, the volume of copper sulfate required is about 16μl / ㎝ 2 ×3.0㎝ 2 = 48 μl.

[0065] 5) Take a 10ml clean beaker, add 48μl prepared copper sulfate mother so...

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Abstract

The invention relates to a method for manifesting metal surface hidden fingerprints through chemical sedimentation, and belongs to the technical field of fingerprints identification. The method takes copper sulfate solution as the replacement reagent, manifests hidden fingerprints on metals such as zinc, magnesium and general carbon steel, and particularly comprises the following steps: copper sulfate solution is prepared by taking copper sulfate and ultrapure water as raw materials, and the concentration of the solution is mainly depended on the nature of metal substrate material; the hidden fingerprint sample is submerged in the copper sulfate solution, or the solution is dropped on the sample material surface, and reaction is carried out for a period of time; the sample is dried by nitrogen after being taken out, the fingerprints can be detected clearly with the naked eye, and the manifested fingerprint image is gathered through a digital camera. According to the manifesting method, no expensive instrument or fluorescent reagent are need, and the manifesting method is simple to operate and fast to manifest fingerprints, is healthy and eco-friendly, low in cost, and ideal in sensitivity, veracity and repeatability, and has better application prospect in the field of fingerprint identification.

Description

technical field [0001] The invention relates to a method for displaying latent fingerprints on a metal surface by using a chemical displacement deposition technology, and belongs to the technical field of fingerprint identification. Background technique [0002] The lines of fingerprints are different in patterns, breakpoints and intersections. They are called features in information processing, and these features are unique and permanent, so we can match a person with his fingerprint Up, by comparing his fingerprints with pre-saved fingerprints, his true identity can be verified. Common fingerprints are divided into three categories: the first category is obvious lines, which are lines that are visible to the naked eye. For example, hand-stained paint, blood, ink and other items are transferred, usually printed on the fingerprint card to become the basic information; the second type is the forming pattern, which refers to the soft material, such as hand contact, imprinted ...

Claims

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Application Information

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IPC IPC(8): A61B5/117
Inventor 张美芹刘守亮秦刚朱雨于溪王美玲张学记
Owner UNIV OF SCI & TECH BEIJING
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