THE ION AGE: New-Type Domestic Appliances Flourish February 7, 2002 Products whose selling point is "the power of the ion" are the new kids on the block in the market for such familiar domestic appliances as refrigerators, air conditioners, and washing machines. More and more functions are being added to these appliances - such as "getting rid of smells and assorted germs" and "enhancing cleaning power." These added benefits are a response to consumers' heightened interest in health issues. Ion engineering is being actively developed as a new core technology for nanotechnology (the production of ultrasmall mechanisms) on a par with lasers. More new products that apply this technology are sure to come onto the market in the future. Refrigerator That Banishes Smells and Germs Ions are atoms or molecules with an electrical charge that float about in the air as positively or negatively charged particles. They exist naturally in moderate concentrations. In autumn 2001, Sharp Corp. put a refrigerator on the market that removes smells and germs by generating ions artificially. The maker's sales point was that the quantities of such things as colon bacilli and mold in the refrigerator are reduced by 90% after one hour in the appliance. This is how it works: First, an electrical discharge splits the molecules of water vapor in the air into positive hydrogen ions and negative oxygen ions. According to the makers, the positive and negative ions float about in the air for a few seconds, and during this time they mop up molecules of bacteria, viruses, and smells, rendering them harmless. The device that generates these ions is housed in a little container about the size of a matchbox situated in the center rear of the refrigerator. It constantly emits ions into the air circulating inside the refrigerator, thus keeping it clean. The manufacturer that developed this method researched ion-purification technology over a period of two years and in autumn 2000 was able to apply the technology in a new model of its air purifier. Sales of its air purifiers jumped fivefold over the year before. According to the company, when the technology was also incorporated in the company's air conditioners four months later, sales of this appliance tripled. The maker explained: "When air is purified by means of a filter, there are places like the space behind cupboards where the air does not circulate, so it does not get filtered. Our aim was a process that works on the air as a whole, so that none of it is left unpurified." "Waterfall Effect" for Air Conditioners and Purifiers   Your Name What did you think of this article? It was interesting. It was boring. Send this article to a friend Trends in Japan Home There are other examples of the successful application of ion technology. An air conditioner put on the market by Toshiba Corp. in October 1999 advertised as "making the air fresh by generating negative ions" is selling well. Air containing a lot of negative ions is said to be conducive to relaxation. The exact effect of negative ions, however, is not yet entirely clear; nor is the mechanism by which a stable quantity could be maintained in the air. In nature negative ions are found in greatest concentration (about 10,000 per cubic centimeter of air) near the bottom of a waterfall, where water spray is violently agitated. The new air conditioner is said to be able to generate the same concentration not just in the center of a room but in all the corners as well. Another manufacturer, Matsushita Seiko, whose ion air conditioner was put on the market in autumn 2000, stresses the method by which the negative ions are generated. Where other makers use an electrical discharge, this company has adopted a method of generating the ions by causing water droplets to collide with each other, thus splitting them. This is how negative ions are produced naturally near waterfalls. It is claimed that because this method is based on the same principle as that of the waterfall, the quantity generated is not excessive, and a natural concentration can be maintained. An additional benefit of this method is that the water functions as a filter to remove smells and dust from the air and also has a humidifying effect. In the past, ions could only be handled in solutions. But thanks to materials technology, which made progress in Japan hand-in-hand with semiconductor technology, it has been possible since the 1970s to work with ions in a vacuum or in air. And as interest in environmental issues grew, the ions came to have applications in such fields as disinfection, breaking down harmful substances, and removing smells. If research on ions continues to make progress and we gain a better understanding of the mechanisms by which their beneficial effects come about, we can expect that even more diverse products applying that understanding will become available. Copyright (c) 2002 Japan Information Network. Edited by Japan Echo Inc. based on domestic Japanese news sources. Articles presented here are offered for reference purposes and do not necessarily represent the policy or views of the Japanese Government.