Engineers develop cheap flexible loudspeaker that's only 0.25mm thick
April 7, 2009 A loudspeaker that’s so flat and flexible it can be tacked to a wall just like a picture? That’s precisely what engineers at Warwick Audio Technologies in the UK have cooked up. The speaker – dubbed the Flat Flexible Loudspeaker (FFL) for obvious reasons – is less than 0.25mm and thin enough to be concealed inside office ceiling tiles, cars or printed with a design and attached to any flat surface, like a wall.
What the super-slim FFL lacks in girth, though, is amply compensated by a method of sound generation that can project a clearer, crisper sound further than conventional speakers. By delivering planar directional sound waves, the loudspeaker doesn’t experience the deterioration in sound quality or volume that occurs with conventional speakers – about 6 decibels each time you double your distance from the driver.
Instead audio is heard at close to the same level whether you’re standing a meter or 10 meters away. This makes the FFL ideal anywhere public address systems are used, such as airports, train stations and shopping centers.The loudspeaker is not only well suited to large public areas. Lightweight and inexpensive to manufacture, the FFL can be used wherever space is at a premium, including the home and car.
“Audio-visual companies are investigating its use as point-of-sale posters for smart audio messaging,” says Steve Couchman, CEO of Warwick Audio Technologies. “Car manufacturers are particularly interested in it for its light weight and thinness, which means it can be incorporated into the headlining of cars, rather than lower down in the interior.”
Warwick Audio Technology’s design has come some way since its early trials involving sheets of tinfoil and baking paper. The flexible speaker laminate now is an assembly of thin conducting and insulating materials that vibrate, when excited by an electrical signal, producing sound. While it adopts the same basic principles of all speakers, the FFL is distinctive in that its entire surface area radiates in phase, producing a plane sound wave with high directivity and accurate sound imaging.
The company, which is linked to the University of Warwick, is still in talks with a number of potential commercial partners and hopes to launch its first product later in the year.