CSI: X-Ray Fingerprints helps find missing and lost children.
Micro-X-Ray Fluorescence Also Provides Chemical Information
Ordinary invasive fingerprinting techniques, such as dusting, are prone to damaging evidence. Micro-X-ray fluorescence images fingerprints without touching them. The process, called MXRF, zaps a print with a tiny X-ray beam that mixes with atoms left behind from sweat or evidence to form an image.
HOW MXRF WORKS: The new technique rapidly reveals the elemental composition of a sample by shining a thin beam of X-rays onto it without disturbing the sample. All chemical elements emit and absorb radiation at a "signature" frequency of light. For instance, sodium emits primarily orange light, while oxygen emits green light. Scientists can pass collected light through an instrument called a spectrograph to spread it into a spectrum, much like visible light spreads into a rainbow of colors by a prism. By carefully studying how the spectrum becomes brighter or darker at each wavelength, scientists can tell what chemical elements are present in a given sample. Chemicals, like potassium,sodium and chlorine from salts excreted in human sweat, then form an image of a fingerprint. This is a new way of visualizing fingerprints in cases where we couldn't detect a fingerprint with the traditional methods. This method also detects unusual chemical elements and their location on the fingerprint, giving valuable clues to investigators.
Scientists say the MXRF technique could be used to better track down lost or missing children. Children's fingerprints are more difficult to detect -- the new method could better detect prints based on chemicals left behind in a child's fingerprints due to food, soil or saliva and this information can be used to track down evidence of the child’s movements. http://www.sciencedaily.com/videos/2006/1208csi_xray_fingerprints.htm
Micro-X-Ray Fluorescence Also Provides Chemical Information
Ordinary invasive fingerprinting techniques, such as dusting, are prone to damaging evidence. Micro-X-ray fluorescence images fingerprints without touching them. The process, called MXRF, zaps a print with a tiny X-ray beam that mixes with atoms left behind from sweat or evidence to form an image.
HOW MXRF WORKS: The new technique rapidly reveals the elemental composition of a sample by shining a thin beam of X-rays onto it without disturbing the sample. All chemical elements emit and absorb radiation at a "signature" frequency of light. For instance, sodium emits primarily orange light, while oxygen emits green light. Scientists can pass collected light through an instrument called a spectrograph to spread it into a spectrum, much like visible light spreads into a rainbow of colors by a prism. By carefully studying how the spectrum becomes brighter or darker at each wavelength, scientists can tell what chemical elements are present in a given sample. Chemicals, like potassium,sodium and chlorine from salts excreted in human sweat, then form an image of a fingerprint. This is a new way of visualizing fingerprints in cases where we couldn't detect a fingerprint with the traditional methods. This method also detects unusual chemical elements and their location on the fingerprint, giving valuable clues to investigators.
Scientists say the MXRF technique could be used to better track down lost or missing children. Children's fingerprints are more difficult to detect -- the new method could better detect prints based on chemicals left behind in a child's fingerprints due to food, soil or saliva and this information can be used to track down evidence of the child’s movements. http://www.sciencedaily.com/videos/2006/1208csi_xray_fingerprints.htm
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