A biochip is a collection of miniaturized test sites (micro arrays) arranged on a solid substrate that permits many tests to be performed
at the same time in order to get higher throughput and speed. Typically, a biochips surface area is not longer than a fingernail. Like a computer chip that can perform millions of mathematical operation in one second, a biochip can perform thousands of biological operations, such as decoding genes, in a few seconds. A genetic biochip is designed to freeze into place the structures of many short strands of DNA (deoxyribonucleic acid), the basic chemical instruction that determines the characteristics of an organism. Effectively, it is used as a kind of test tube for real chemical samples. A specifically designed microscope can determine where the sample hybridized with DNA strands in the biochip. Biochips helped to dramatically increase the speed of the identification of the estimated 80,000 genes in human DNA, in the world wide research collaboration known as the Human Genome Project. The microchip is described as a sort of word search function that can quickly sequence DNA. In addition to genetic applications, the biochip is being used in toxicological, protein, and biochemical research. Biochips can also be used to rapidly detect chemical agents used in biological warfare so that defensive measures can be taken. Motorola, Hitachi, IBM, Texas Instruments have entered into the biochip business.
STRUCTURE AND WORKING OF AN ALREADY IMPLANTED SYSTEM
The biochip implants system consists of two components: a transponder and a reader or scanner. The transponder is the actual biochip implant. The biochip system is radio frequency identification (RFID) system, using low-frequency radio signals to communicate between the biochip and reader. The reading range or activation range, between reader and biochip is small, normally between 2 and 12 inches.
1.
The Transponder
The transponder is the actual biochip implant. It is a passive transponder, meaning it contains no battery or energy of its own. In comparison, an active transponder would provide its own energy source, normally a small battery. Because the passive contains no battery, or nothing to wear out, it has a very long life up to 99 years, and no maintenance. Being passive, it is inactive until the reader activates it by sending it a low-power electrical charge. The reader reads or scans the implanted biochip and receives back data (in this case an identification number) from the biochips. The communication between biochip and reader is via low-frequency radio waves. Since the communication is via very low frequency radio waves it is not at all harmful to the human body. The biochip-transponder consists of four parts; computer microchip, antenna coil, capacitor and the glass capsule.
Figure 1:COMPONENTS OF THE BIOCHIP
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2.
Computer microchips
The microchip stores a unique identification number from 10 to 15 digits long. The storage capacity of the current microchips is limited, capable of storing only a single ID number. AVID (American Veterinary Identification Devices), claims their chips, using a nnn-nnn-nnn format, has the capability of over 70 trillion unique numbers. The unique ID number is etched or encoded via a laser
onto the surface of the microchip before assembly. Once the number is encoded it is impossible to alter. The microchip also contains the electronic circuitry necessary to transmit the ID number to the reader.
Figure 2:MICROCHIP
3.
Antenna Coil
This is normally a simple, coil of copper wire around a ferrite or iron core. This tiny, primitive, radio antenna receives and sends signals from the reader or scanner.
Figure 3:ANTENNA COIL
4.
Tuning Capacitor The capacitor stores the small electrical charge (less than 1/1000 of a watt) sent by the
reader or scanner, which activates the transponder. This activation allows the transponder to send back the ID number encoded in the computer chip. Because radio waves are utilized to
communicate between the transponder and reader, the capacitor is tuned to the same frequency as the reader.
Figure 4:TUNING CAPACITOR
5.
Glass Capsule The glass capsule houses the microchip, antenna coil and capacitor. It is a small capsule,
the smallest measuring 11 mm in length and 2 mm in diameter, about the size of an uncooked grain of rice. The capsule is made of biocompatible material such as soda lime glass. After assembly, the capsule is hermetically (air-tight) sealed, so no bodily fluids can touch the electronics inside. Because the glass is very smooth and susceptible to movement, a material such as a polypropylene polymer sheath is attached to one end of the capsule. This sheath provides a compatible surface which the boldly tissue fibers bond or interconnect, resulting in a permanent placement of the biochip. The biochip is inserted into the subject with a hypodermic syringe. Injection is safe and simple, comparable to common vaccines. Anesthesia is not required nor recommended.
6.
The reader The reader consists of an exciter coil which creates an electromagnetic field that, via radio
signals, provides the necessary energy (less than 1/1000 of a watt) to excite or activate the implanted biochip. The reader also carries a receiving coil that receives the transmitted code or ID number sent back from the activated implanted biochip. This all takes place very fast, in milliseconds.
The reader also contains the software and components to decode the received code and display the result in an LCD display. The reader can include a RS-232 port to attach a computer.
Figure 5:READER
7.
How it works The reader generates a low-power, electromagnetic field, in this case via radio signals, which
activates the implanted biochip. This activation enables the biochip to send the ID code back to the reader via radio signals. The reader amplifies the received code, converts it to digital format, decodes and displays the ID number on the readers LCD display. The reader must normally be between 2 and 12 inches near the biochip to communicate. The reader and biochip can communicate through most materials, except metal.
