Single-celled plankton creatures will lead to a breakthrough in nanofabrication of computer chips

Moths are single-celled creatures that live in oceans, lakes and even mud. They create around themselves shells in various complex shapes, surrounding them from all directions. And of all the creatures in the world, it is possible that these tiny creatures will bring about the next revolution in the production of computer chips

If we take a handful of sand from the beach and look at it with the help of the microscope, we will discover before our lingering eyes a whole world. The small and simple grains of sand are actually made up of thousands of fragments of magnificently shaped shells. Under the lens of the microscope we will discover towering cathedral spiers, complex geometric shapes, spreading fans and many other shells. Most of them belong to creatures called formants. There are more than 100,000 different species of barnacles, and each of those species has a different and unique shell.

Moths are single-celled creatures that live in oceans, lakes and even mud. They create around themselves shells in various complex shapes, surrounding them from all directions. And of all the creatures in the world, it is possible that these tiny creatures will bring about the next revolution in the production of computer chips.

The molders build their hard shell walls by creating and placing submicron rows of silica - a molder that is also used as a key material in the semiconductor industry. "If we can control these processes genetically, we'll have a whole new way to make nanoscale computer chips," says Michael Sussman, professor of biochemistry at the University of Wisconsin-Madison.

In order to reach this goal, a research group led by Sussman and Virginia Armbrust - a mold expert from the University of Washington - reported finding a series of genes specifically involved in the production of silica and its processing in the mold Thalassiosira pseudonana. The study was published today in the early online edition of PNAS.

The new data will allow Sussman to begin manipulating the genes responsible for creating silica, and hopefully use them to create rows of silica on computer chips. This advance in chip manufacturing could greatly increase processing speed, according to Sussman, because molders are able to produce much thinner silicon lines than current technology allows.

"The semiconductor industry has managed to double the density of transistors on computer chips every few years. They did this by using photolithography techniques (which involve the use of a powerful laser) in the last 30 years," explains Sussman. "But they are now approaching the resolution limit of visible light."

Until Sussman decided to take an interest in the engineering skills of the terrapins, the main interest in them came from ecologists who were trying to assess their role in the Earth's carbon cycle. The small forms obtain the energy necessary for their existence through photosynthesis, which utilizes the carbon dioxide in the air and water and when they die they sink to the bottom of the ocean. They drain 20% of the carbon dioxide in the atmosphere every year. A similar amount of carbon dioxide is drained from the atmosphere each year by all the rainforests combined.

But the research on the forms revealed other fascinating possibilities. When Sussman learned about the forms, he was surprised to learn about the huge variety that exists in the different shells. He realized that there must be unique mechanisms that control the arrangement of the silica molecules to create the unique shell pattern for each species.

In order to determine which genes are involved in the design of the various shells, the research team used a DNA chip developed by Sussman, Franco Karina and Fred Blattner - an electrical engineer and a geneticist, respectively. Together, the three founded the biotechnology company NimbleGen. The chip allowed the three scientists to find out which genes are involved in various cellular processes. In this case, the chip identified genes that responded when the molds were grown in low levels of silicic acid - the raw material they use to make silica.

The low levels of silicic acid actually meant that the molds were starved. In this state of extreme hunger for the raw material for silica, 30 genes 'went crazy' and began to over-act. Of these, 25 genes are completely new and do not resemble other known genes.

"There are 13,000 genes in the organism. Now that we know that there is a high probability that our 30 genes are involved in processing silica, we can focus on them and start manipulating and changing them with genetic engineering and see what happens," says Sussman.

If and when the technology based on the operation of the form factor gardens reaches full implementation, then it will bring about a revolution - and not only in the field of semiconductors. Those genes code for enzymes - nanomachines the size of individual molecules - capable of turning the silicic acid into individual molecules of silica and sequencing them in a way determined by the shape's programmers. The enslaved shapers will be able to create virtually any three-dimensional shape from silica. This will be the first step in the nanotechnological revolution that manipulates individual molecules and atoms. The success of the project will result in a search for other unicellular organisms that contain enzymes capable of transporting and sequencing other molecules, not just silica. Discoveries of such enzymes and understanding their function will mean that in the future we will be able to produce strong, defect-free and highly complex materials, cheaply and efficiently, atom by atom.

For information on the University of Washington website

Links to the scanning electron microscope images of the forms:
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