Monday, March 1, 2010
Cell inspired electronics
Cell inspired electronics
A single cell in the human body is approximately 10 000 times more energy-efficient than any nanoscale digital transistor, the fundamental building block of electronic chips. In one second, a cell performs about 10 million energy-consuming chemical reactions, which altogether require about one picowatt (one millionth millionth of a watt) of power.
Rahul Sarpeshkar of the Massachusetts Institute of Technology (MIT) is now applying architectural principles from these ultra-energy-efficient cells to the design of low-power, highly parallel, hybrid analogue-digital electronic circuits. Such circuits could one day be used to create ultra-fast supercomputers that predict complex cell responses to drugs. They may also help researchers to design synthetic genetic circuits in cells.
In his new book, Ultra Low Power Bioelectronics (Cambridge University Press, 2010), Sarpeshkar outlines the deep underlying similarities between chemical reactions that occur in a cell and the flow of current through an analogue electronic circuit. He discusses how biological cells perform reliable computation with unreliable components and noise (which refers to random variations in signals — whether electronic or genetic). Circuits built with similar design principles in the future can be made robust to electronic noise and unreliable electronic components while remaining highly energy efficient. Promising applications include image processors in cellphones or brain implants for the blind.
"Circuits are a language for representing and trying to understand almost anything, whether it be networks in biology or cars," says Sarpeshkar, an associate professor of electrical engineering and computer science. "There's a unified way of looking at the biological world through circuits that is very powerful."
Circuit designers already know hundreds of strategies to run analogue circuits at low power, amplify signals, and reduce noise, which have helped them design low-power electronics such as mobile phones, MP3 players and laptop computers.
"Here's a field that has devoted 50 years to studying the design of complex systems," says Sarpeshkar, referring to electrical engineering. "We can now start to think of biology in the same way." He hopes that physicists, engineers, biologists and biological engineers will work together to pioneer this new field, which he has dubbed "cytomorphic" (cell-inspired or cell-transforming) electronics.
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