Wha are Capacitive Sensors?

Forensic dactyloscopy is the study of fingerprints. Visible prints may be left behind by substances that stick to the fingers such as dirt or blood. Latent fingerprints are traces of sweat, oil or other natural secretions on the skin and are not ordinarily visible. These can be made visible by dusting techniques when the surface is hard and by chemical techniques when the surface is porous. Fingerprints provide police with extremely strong physical evidence tying suspects to evidence or crime scenes. Today police in most countries use systems for matching prints found at crime scenes to suspects, called automated fingerprint identification systems (AFIS), to search rapidly through millions of digitised fingerprint records. Fingerprints recognised

Here, instead of U.V light, a visible light was used. The light source used was a variable light source, which enabled us to change the wavelengths of the visible light. The latent fingerprint was attempted to be excited using a variable visible light source to determine if the fingerprint fluoresce within a specific visible light wavelength. The light wavelength was increased from 425nm to 700nm with 25nm in each step. Multiple images were photographed within each level, using spectral filters and camera settings in order to capture any fluorescence that the fingerprint might

During the identification phase, the user puts the finger on the same sensor, generating a new fingerprint image or template called query print. Minutiae points are carried out from the query print, and the matcher module compares the set of query minutia with the stored minutia templates or image in the enrollment database to find the number of similar minutia points. Because of variations present in finger placement and pressure applied to the sensor, the minutia points take out from the template and query fingerprints must be lined up, or submitted before matching. After line up the fingerprints, the matcher decides the number of pairs of matching minutiae-two minutiae points that have similar location and directions. The system decides the user's identity by comparing the match score to a

Lee, H. (2001). Advances in Fingerprint Technology, Second Edition, 2nd Edition. Retrieved January 26, 2015, from Vital Source: http://online.vitalsource.com/books/9781420041347

Technology is always improving, and new software is always being developed. One of these new technologies that have been developed is biometrics. Biometrics is the process by which a person's unique physical and other traits are detected and recorded by an electronic device or system as means of confirming identity (Dictionary.com, 2013). In recent years, the FBI has employed new biometrics technology.

Face recognition is another biometric technology. Face recognition uses the same technology that iris recognition uses. For face recognition, a camera takes several images of a person to find out who it is. Face recognition differs from all of the other biometric technologies because the person that is in the picture does not have to cooperate with the process. In all of the other technologies it requires the people to actively participate in the process. In face recognition, the image can be taken without the person even knowing that it took place.

• Un-Cooled – This is the most common type of thermal-imaging device. The infrared-detector elements are contained in a unit that operates at room temperature. This type of system is completely quiet, activate immediately and has the battery built right in.

People touch thousands of surfaces every day; door handles, desks, light switches, etc. When they touch these surface they leave their own unique marks on them, their fingerprint. When a person leaves a fingerprint they also leaving thousands of different chemicals, chemicals that all react differently over time. A fingerprint is composed of peaks, raised ridges which appear black in Figure 1, and valleys, recessed furrows which appear to be white in Figure 1, which make a distinct individual pattern. These patterns are categorized in three distinct patterns for examination purposes; the loop, the whorl, and the arch. Examples of these patterns are shown in Figure 1.

Fingerprints are impressions left by friction ridges present on the skin of fingertips [Champod & Lennard 2004; Mozayani & Noziglia 2006]. Each friction ridge contains pores that are attached to sweat glands under the skin. These ridges are formed in the dermal papillae, the uppermost part of the dermal layer, and can be found on the soles of the feet and palms of the hand (Figure 1.1) [Champod & Lennard 2004; Mozayani & Noziglia 2006]. The ridge patterns can be physically examined to determine points of identification when comparing a sample fingerprint to an exemplar. A detailed description of these patterns is provided by Lee and Harris (2006).

In other research, eccrine sweat, together with oily substances forms an impression of the finger ridge pattern when a finger touches a surface, known as a latent fingermark (Hazarika & Russell 2012). For enable the latent fingermark to visualize, physical or chemical treatments are required

A dim light scene enters the lens at the front. The light is made of photons. An image intensifier night vision device is an optical device that does exactly what you would think from the name. It takes available light and intensifies it.

There are three types of fingerprints: visible, plastic and latent. The visible fingerprint is the one, which is made with ink and can be seen easily. These can be made by the traditional technique, which uses the help of ink to see the person’s prints when pressed onto a paper. The plastic fingerprint is one that is made with materials like soap and wax. The last type is known as latent fingerprints. The impressions created on a surface by means of perspiration or natural oils are called latent fingerprints. To make a latent fingerprint visible you dust it with powders and lift it with tape. Another technique to getting fingerprints is by the

Every time somebody touches something, they leave behind a unique signature that forever links them to that object. This link is their fingerprints, which are unique to every person, for no two people have the same set, not even family members or identical twins. Palms and toes also leave prints behind, but these are far less commonly found during crime scene investigations. Therefore, fingerprints provide an identification process that is applicable to background checks, biometric security, mass disaster identification, and most importantly, crime scene investigations. Fingerprints are so differentiated because they are made up of distinct patterns of ridges and furrows on the fingers. The ridges are the “raised” portions of the prints, and the furrows are the “recessed” portions. This perceived uniqueness has led some people to falsely accept fingerprint analysis as absolute scientific fact. Although overall fingerprints are reliable, there are definitely situations where their accuracy can come into question.

Pyrometer is a touch less type temperature measuring device. In other words, pyrometer is a transducer that makes use of the visible or invisible radiation emitted by an object to determine its temperature without any physical contact with it. It is used to measure the surface temperatures of very hot objects like furnaces and distant objects without actually being in contact with it. It intercepts and measures the thermal radiation emitted by the object, a process called pyrometry.The word pyrometer originated from the Greek word for fire, "πυρ" (pyro) and meter meaning to measure. Due to its speed, accuracy, specific advantages and economy, pyrometer is gaining acceptance in new fields.

The technology is many years away from development. Blood pulses on a finger can be measured by new biometric systems. This technology is currently under development. Nail bed identification is based on identifying distinct spatial arrangement beneath the fingernail. Gait recognition is another technology which is under development. This recognizes individuals by their distinctive walk and captures a sequence of images to derive and analyze motion characteristics. The technology is currently under development and its complete potential and limitations can be fully assessed. Many biometric identification systems are being developed and tested (Woodward, 2005).