Ever get that feeling that the speakers in your living room are too, well, opaque? Wouldn't it be cool if it looked like they were just floating there in mid-air blasting jams for all to hear? It's a heck of a dream, and thanks to a team of Harvard scientists, it might just come true for you.
These Harvard engineers recently built a stretchable ionic speaker out of gel that's as transparent as a window. Able to play the entire audible spectrum—20 hertz to 20 kilohertz—it also sounds pretty good. The construction is relatively simple. It's just a clear piece of stretchable, insulating rubber that's sandwiched between two layers of hydrogel—the ionic conductor. The resultant shape is then hooked up to copper electrodes that send a high voltage electric blast through the whole thing causing the rubber to vibrate. It's thin enough and clear enough that the engineers think it could coat the front of a TV and provide sound without any other external speaker.
The look of the almost-invisible speaker is impressive enough, but what the scientists are really excited about is the ionic conductor. Unlike regular electronics that send a signal over electrons, ionic devices sends it over ions, and this is the first device to show that the system can power conventional electronics. Because they're more stretchable and adaptable than traditional electronics, ambitions for ionic conductors range from versatile electronics like this speaker to revolutionary biomechanical devices like artificial organs. All else fails, this technology could be the building blocks for the world's coolest, loudest and clearest living room entertainment system. [New Scientist, Harvard]