Patent registrations for ``metal foam'' products have significantly increased over the past 10 years, as scientists and engineers try to adopt the bubble-filled metals in building safer and lighter vehicles.
The Korea Intellectual Property Office said Monday that the numbers of patent filings for metal foam have been rising steadily in Korea, Japan, Germany and the United States since 1988. Considering the increases, each country's government is believed to be supporting metal foam research to gain a foothold in what is seen as a lucrative market with great potential, the office said.
Metal foam, or sponge metal, is made by inflating solid metal _ usually aluminum _ with gas, just like baking cakes with baking powder. It forms many holes in the metal structure similar to sponges, and typically more than 80 percent of the volume is void space, making it light enough to float on water and save fuel when applied to automobiles or airplanes.
Metal foam has been used in many industrial sectors, such as industrial filters, fuel cells, industrial mufflers and industrial radiators. But it will be probably most useful in making car bumpers and other shock-absorbing parts of vehicles, said Jung Sang-ik, an official at the patent agency.
``Many nations can produce bulk metal foam in rectangular shapes, but the key point is how to shape it like a bumper and how to maintain its density and durability while doing so. That is why the metal foam bumper is not commercialized yet,'' he said. ``Japan and Germany are leading in this sector, and we are following closely behind them. It seems that many institutions and universities are paying more and more attention to metal foam research.''
There are two types of metal foam _ open-cell and closed-cell. The open types are easier to produce and have been utilized in many sectors. The closed types, of which the pores are filled with gas, were only invented in the 1990s, and have been studied for use primarily as impact-absorbing material.
indizio@koreatimes.co.kr