SHARING RESOURCES
Imagine getting in a car and having it adjust its settings to the way you like them, grabbing a door handle that knows if you are authorized to open it or shaking hands with someone and invisibly exchanging electronic business cards. What if you could walk into a room and connect to a network just by setting your laptop on a table? In 2020, whipping out your mobile phone to make a call will be quaintly passé. By then phones will be printed directly on to wrists, or other parts of the body. Who can imagine that soon our body can be the backbone of a broadband personal data network linking our mobile phone or MP3 player to a cordless headset, our digital camera to a PC or printer, and all the gadgets one carries around to each other. Japan''s Nippon Telegraph and Telephone Corp. have developed a system that can do these things and others by using your body to create a high-speed computer network. The system, called RedTacton, grew out of a different research project and came about somewhat by accident. NTT researchers were working on an ultra-sensitive system for measuring voltages in chip circuits when an engineer discovered by chance that his body could carry a weak signal. Work began on that discovery as an additional project, and thus RedTacton was born. RedTacton enables the first practical Human Area Network between body-centered electronic devices and PCs or other network devices embedded in the environment via a new generation of user interface based on totally natural human actions such as touching, holding, sitting, walking, or stepping on a particular spot. Similar weak electrical fields can be found around many objects, including those made from metals, plastic, glass, ceramics and liquids, which means they can also be part of a RedTacton network. The system can work through clothing such as socks, shoes and gloves, and on both dry and oily skin. A person equipped with a sensor can exchange data with another person carrying a sensor by shaking hands, and between a person and a device by touching it, walking on it or sitting on it.
RedTacton sends a signal through the very small electrical field that is emitted by, and exists around, the human body. The electric field replaces any cables or
wireless link that might otherwise be used. RedTacton uses the human body’s weak electric field and conductive properties to transform special transceivers that people wear into "Human Area Networks" that can transmit data at up to 10Mbps, the speed of a fast Ethernet (network) device. Devices, such as PDAs and cell phones, and environmental objects, such as tables and doorknobs, equipped with similar transceivers can then capture the data. But apart from that, why bother with RedTacton when Bluetooth can already do the job wirelessly? The answer is simple. With Bluetooth, it is difficult to rein in the signal and restrict it to the device you are trying to connect to. You usually want to communicate with one particular thing, but in a busy place there could be hundreds of Bluetooth devices within range. Unlike earlier failed touch-transmission systems that attempted to harness the flow of the human electric field to transmit data, RedTacton instead focuses on fluctuations in the field that occur when a touch connection is made that links two or more transceivers. A "photonic electric field sensor" embedded in the receiver uses a laser to measure changes in an electro-optic crystal. Those minute changes are then converted and transmitted as digital information. A RedTacton transmitter couples with extremely weak electric fields on the surface of the body. The weak electric fields pass through the body to a RedTacton receiver, where the weak electric field affects the optical properties of an electro-optic crystal. The extent to which the optical properties are changed is detected by laser light whiis then converted to an electrical signal by a detector circuit. The major features of this device are, a communications path can be created with a simple touch, automatically initiating the flow of data between a body-centric electronic device and a computer that is embedded in the environment. For example, two people equipped with RedTacton devices could exchange data just by shaking hands. A wide range of natural human actions -- grasping, sitting down, walking, or standing in a particular place -- can be used to trigger RedTacton to start a networked process. Print out where you want just by touching the desired printer with one hand and a PC or digital camera with the other hand to make the link. Complicated configurations are reduced by downloading device drivers "at first touch". RedTacton can carry music or video between headsets, mobile devices, mobile phones, etc. Users can listen to music from a RedTacton player simply by putting on a headset or holding a viewer. RedTacton can utilize a wide range of materials as a transmission medium, as long as the material is conductive and dielectric, which includes water and other liquids, various metals, certain plastics, glass, etc. Using ordinary structures such as tables and walls that are familiar and readily available, one could easily construct a seamless
communication environment at very low cost using RedTacton . The system is also being considered for computer networking. Tables equipped with sensors could form an ad-hoc computer network when people with suitably equipped PCs place their notebooks on them, or a computer could send audio files to an MP3 player without cables. Human society is entering an era of universal computing, where everything is networked. By making Human Area Networks feasible, RedTacton will enable ubiquitous services based on human-centered interactions and therefore more intimate easier for people to use.