Pretty much anything can be a computer, if it can compute logical functions, store data, and transmit information - even living cells. A team at Stanford University has accomplished one of the the final tasks necessary to turn cells into working computers: They've created a biological transistor, called a transcriptor, that uses DNA and RNA instead of electrons and responds to logical functions.
Not all computers are made of silicon. By definition, a computer is anything that processes data, performs calculations, or uses so-called logic gates to turn inputs (for example, 1s and 0s in binary code) into outputs. And now, a small international community of scientists is working to expand the realm of computers to include cells, animals, and other living organisms. Some of their experiments are highly theoretical; others represent the first steps toward usable biological computers. All are attempts to make life perform work now done by chips and circuit boards.
As silicon microchips get smaller and manufacturers pack more and more transistors onto each individual chip, Moore's Law - the optimistic observation that the microchip industry doubles the number of transistors it can build on a single chip every 12 to 18 months - becomes a little more difficult to maintain. But IBM researchers are reporting a breakthrough in transistor technology that could allow them to further reduce the size of logic gates - the fundamental digital switches on the modern microchip - and therefore continue shrinking microchips for another decade or more, enabling our gadgets to continue growing faster, more powerful, and (hopefully) more efficient.
A new biologic logic gate based on proteins can perform binary calculations, serving as the first "cellular calculator," researchers say. Various combinations of components can be arranged into circuit elements, leading to specific metabolic processes inside a cell. The setup can answer mathematical questions in a similar fashion to a computer.
