A computer component that uses vibrations rather than electrons could approach the physical lower limit for energy use when processing and sending information.
The minimum amount of energy needed for a computer to perform a computational step is called the 鈥淟andauer limit鈥�, named after the 1960s physicists Rolf Landauer. In his calculations, Landauer did not consider any specific computer design, but rather the basic energy cost required to manipulate information, like erasing or re-writing a bit.
Conventional computers, which are made of semiconductors, work by controlling the flow of electrons within different circuits to perform operations. Stopping thermal fluctuations from affecting the electrons鈥� movements and causing errors incurs energy costs. Consequently, energy consumption of conventional computers is about ten thousand times larger than the Landauer limit. Nanomechanical computers that use tiny vibrations instead of electrons, however, wouldn鈥檛 have this additional energy cost.
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at the University of Queensland in Australia and his colleagues have now created a nanomechanical logic gate, which is a basic building block needed for such a computer.
The new gate contains a membrane a thousand times thinner than a human hair. Bowen says it鈥檚 like a 鈥渘anoscopic trampoline鈥� that can vibrate with a low or a high amplitude. The two amplitudes correspond to 0 and 1 values in an electronic computer, so basic computations can be done by amplifying or dampening them.
Information is inputted into the gate by a sound wave, a traveling vibration. The gate鈥檚 output, which is just a very simple computation, can then be fed into another gate of the same design by a sound wave as well. Sound propagating between chips plays the role of electrons moving through wires in a conventional computer.
鈥淎nything you can do with an electronic, semiconductor computer, you could do with these [nanomechanical] computers,鈥� says Bowen.
At the same time, Bowen says that the new gate does not yet operate at the Landauer limit and his team is relying on theoretical calculations that show the gate must be about a thousand times smaller to actually get there. They are also working on ironing out all the practical details of connecting many gates together.
at Boston University, who鈥檚 team created some of the first nanomechanical gates over 15 years ago, says that it is now also possible to mass produce nanomechanical gates on silicon chips in commercial facilities.
Nanomechanical computers are unlikely to replace the machines in our homes, but they may prove uniquely suited for use on satellites, says Bowen. A nanomechanical computer free of wires and electronics could withstand extreme conditions like solar flares, stopping it from losing information in such an event, he says.
Reference: arXiv,
