Ok, not your usual Conch-L thread BUT  a strange new world ,,,,,, please read on......

High-Protein Computers


Carol Levin

The promise of binary biology.
Chemistry professor Robert Birge may look as if he's brewing beer in his lab at Syracuse University, but what he's really
doing is recreating the environment of a salt marsh, the ideal incubator for growing bacteria that make a certain protein
that shows great promise as the basis for a radically new kind of memory: protein memory.

Imagine a storage medium the size of a sugar cube that stores a terabyte of information. As odd as it may seem, this device
will be based not on silicon transistors, but on protein molecules that change their shape when exposed to light, enabling
them to store and transfer massive amounts of data.

While research and development efforts today focus on shrinking the size of silicon transistors, there's also an effort afoot
to manipulate tiny protein molecules that may turn out to be economical for storing data on a massive scale. According to
Birge, director of the W.M. Keck Center for Molecular Electronics at Syracuse University, "The size of a single logic gate
will approach the size of a molecule by about the year 2030."

This branch of bioelectronics emerged in the early 1970s when two scientists observed the structural changes that a protein
molecule known as bacteriorhodopsin (which is grown by a bacterium that is found in plentiful supply in salt marshes
throughout the world) exhibited when exposed to light. Later, Soviet scientists recognized the potential of the molecule to
act as a switch with on and off positions, essentially the same binary function that a silicon transistor serves. While
silicon alters its state when a current of electricity excites electrons, a protein changes its shape upon absorbing light. A
laser beam controls the switching in a matrix of memory cells (see diagram).

So would you feel comfortable entrusting your data to a close relative of a protein shake? While an organic entity seems
susceptible to decay, disease, or a ravenously hungry user, this bacterium and its photosynthetic protein, which thrives
naturally in the harsh environment of salt marshes, is resilient and stable. Reliability is another issue. "Writing is a
piece of cake. It's reading that's harder," says Birge. Errors crop up because of noise from the laser interfering with the
read signal. The goal is to reduce the errors to the level found in silicon.


While in terms of speed, protein-based memory falls somewhere between a high-speed disk drive and semiconductor memory, the
advantage is in its ability to read data in parallel. Birge anticipates the major impact of bioelectronics will be in the
area of 3-D memory, which stores data in all three dimensions. Magnetic, flash, semiconductor, and optical memory store data
only on the surface. "The approach we're taking is to have true volumetric memory where you would gain a 300-fold improvement
[in density]," says Birge.

The Syracuse lab has been working on prototypes of protein-based 3-D memory and associative memory (used in neural networks
and artificial intelligence), and is preparing to test memory cards in PCs. The question that hasn't been answered yet is
whether protein memory is economically viable, especially as flash memory improves.

The first hybrid products that use both semiconductor and protein memory (a system would have, say, 3GB to 24GB of protein
memory and 4MB of fast RAM) could reach consumers in as soon as eight years, Birge says optimistically.

But these developments depend on a few contingencies. Inexpensive lasers are needed, and some company will have to buy into
the technology. Birge says that three companies are evaluating the technology now. "They range from very, very large down to
startup."