Technofile : Radio shield

A rubber vest can protect people with pacemakers from interference by cellular telephones. The Tsuchiya Rubber Company of Kashima, Japan, has developed a synthetic rubber that conducts electricity as well as metal does, and so blocks electromagnetic radiation. A 4-millimetre layer of the material is as effective as a 2-millimetre sheet of aluminium or copper and is flexible enough to be made into clothing.