my recent articles |
| Computing with bubbles |
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9 February 2007, for Nature Network Boston Electrons racing through circuits form the heart of today’s computers. Bubbles of gas could also serve as bits of information, performing all the basic steps needed for computation, according to a new paper in Science from MIT. Manu Prakash and Neil Gershenfeld at MIT’s Center for Bits and Atoms created lab-on-a-chip systems where bubbles of nitrogen gas course through tiny water channels. Because the concentration of bubbles in a channel affects how quickly the fluid flows through it, the researchers were able to control how the bubbles moved through intersections of those channels. By precisely shaping those intersections, the researchers got them to perform like logic gates. These gates sorted the bubbles, sending them down one path or another, depending on how the bubbles encountered each other at these crossroads. For example, if two bubbles met at an intersection designed to work as an “AND” logic gate, the bubbles joined together and traveled down one of two channels. The researchers were able to join these gates in more complex combinations, making a so-called ring oscillator, for example, that could keep time (see photo).
Another local group, led by George Whitesides at Harvard, demonstrated, in the same issue of Science, a similar system to encode information using water droplets flowing through small channels of an oily liquid. These liquid computers aren’t likely to replace our laptops, but they could be useful for programming lab-on-a-chip systems to do much more complex reactions, the researchers say. |
A bubble computer