Getting Your Body (And Soul) Wired.(touch technology transmits through the body)

Byline: Kay Itoi

In his gadget-filled office at Tokyo Medical and Dental University, Prof. Kohji Mitsubayashi tells a visitor to touch a transmitter with one hand and a receiver with another. Voila! A jaunty TV jingle blares from a pair of attached speakers. Surprised, the visitor releases both gadgets, and the music stops. The simplicity and strangeness of becoming a human circuit--with electrical signals coursing through one's body from fingertip to fingertip--is so fascinating that visitors usually repeat the act. "Fun, isn't it?" says Mitsubayashi, grinning.

Not just fun. Japan is abuzz over the potential of such body-based technology as the ultimate wireless networking tool. A string of Japanese companies are experimenting with systems that use the human body to conduct electricity--some manipulating weak currents that pass through the skin itself (as body-fat scales do), others taking advantage of electrical fields on the surface of the body. Associated products are on the way. The question is whether this represents a paradigm shift in the way we think about wires.

Sending electrical signals through the body has several advantages over existing wireless systems like Bluetooth and Wi-Fi. For one thing, it's intuitive by nature and doesn't require complicated setup. It is also more secure because the signals can only be intercepted through touch, unlike Bluetooth, which produces stray signals. Last year Matsushita Electric Works released an electric scale, the first appliance based on so-called touch technology. Food trays were embedded with tiny chips that, when touched by a salesclerk, transmitted the price per gram through his or her fingers to a wristwatchlike device. As the clerk weighed the salad, the scale used that data to compute the price of the order. Telecom giant NTT has gone one step further, developing devices that create tiny electric fields on the surface of the ...