- What makes DNA an ideal replacement for silicon-based chips?
- Microsoft takes a leap into the DNA computing world
- The development of DNA-based computers is held back by a cash squeeze
50 years ago, the smallest computers in the world weren’t that small. In fact, they were the size of an average room. Not only did they use a lot of electricity, but they also generated a lot of heat, which often caused problems. Then came a new generation of tiny electronic components, known as microprocessors, which allowed computers to shrink in size and grow in power. This made them far more useful and encouraged their rapid adoption. When these microprocessors first appeared, they were built on conventional silicon chips. And though you’d expect that they’ve changed a lot over the years, microprocessors today rely on the same material and the same basic tech. They’ve been refined nearly to the limits of physics, but today’s chips are still silicon-based processors. And although silicon has been a great material for microprocessors, it’s not the best - and it’s certainly not the most reliable, either.
In fact, a group of researchers from The University of Manchester proposed a far better alternative. As strange as it seems, the team thinks that DNA is the secret to a super powerful computer that “grows as it computes”. The project, which was published in the Journal of the Royal Society Interface, is based on the theory that DNA strands can be used to store and compute data, just like regular microprocessors. And the researchers believe that computers operated by DNA microchips could solve complex problems much faster than traditional ones.
What makes DNA an ideal replacement for silicon-based chips?
What makes this approach so exciting is that it’s potentially much, much faster than those we already have on the market. That’s because DNA-based computers can work on two completely different problems at the same time. Professor Ross D. King, the project leader, describes it as something akin to the process of finding information in a maze. Imagine that your computer is searching for a specific piece of information in a labyrinth. Once it gets to a crossroad where it can go either left or right, a typical computer tries one path first. Then, if it fails to find the information there, it’ll go back and try the second. This is because traditional computers rely on binary code, 1s and 0s. There are only these two possibilities at the most elemental level. But DNA offers four: G, T, C, and A. And those additional possibilities allow it to run much, much faster, especially for complex calculations.
For instance, for a conventional binary processor, really complex mathematical problems are simply too much. It’s estimated that it would take hundreds of years for a conventional computer to solve the really hard ones, whereas a DNA-based computer could potentially solve them in a couple of hours. And this is where DNA computers truly shine. Unlike conventional computers, DNA-based computers can take more than one path at the same time, as if they were replicating themselves at each point in the maze. Moreover, “All electronic computers have a fixed number of chips,” he explains. “Our computer’s ability to grow as it computes makes it faster than any other form of computer, and enables the solution of many computational problems previously considered impossible.”
Another advantage of DNA computers is their capacity to store large amounts of data. Silicon-based microprocessors enable computers to store a maximum of a few terabytes of data. That’s a lot, but a single gram of DNA, for example, could store 100 billion terabytes of data, and since DNA microprocessors are much smaller in size, an average desktop computer could be equipped with more than one DNA microprocessor, achieving even greater speeds and storage capacity. As Professor King puts it, due to the miniscule size of DNA, a “desktop computer could potentially utilize more processors than all the electronic computers in the world combined - and therefore outperform the world’s current fastest supercomputer, while consuming a tiny fraction of its energy”.
DNA storage is super-safe, too. As George Church, a geneticist and expert on DNA from Harvard University, emphasised, DNA is an awesome storage medium because of its durability and stability. For example, at sub-zero temperatures, DNA can last for thousands of years. Most digital data today is usually stored on media with limited lifespans. Take conventional storage solutions such as SD cards and flash drives as an example. If taken care of correctly, these can last you up to 10 years, while more traditional tools such as CDs or DVDs have a lifespan of between two to five years. Clearly, DNA is the better storage option.
Microsoft takes a leap into the DNA computing world
Scientists from The University of Manchester weren’t the only ones who were intrigued by DNA computers. In 2017, Microsoft announced it’ll start developing a DNA-based computer in the next three years. The first model, once fully developed, is expected to store only information such as medical records and police video footage. And it’ll still be larger than conventional desktop computers. According to Doug Carmean, a partner architect at Microsoft Research, the computer will be the size of a Xerox machine from the 1970s. But this isn’t the first time that Microsoft tapped into the potential of DNA as a data storage solution. In 2016, they collaborated with the University of Washington, and set a record by storing 200 megabytes of data onto DNA. Since then, they improved their system, and today it stores 400 megabytes of DNA-encoded data.
The development of DNA-based computers held back by a cash squeeze
Despite all these breakthroughs, we’re still using traditional computers and we rely on their limited storage capacity. If you’re wondering why, just keep in mind that storing even a tiny piece of information in DNA form can cost a small fortune. Only one megabyte of data stored biologically is estimated to cost $12,500. However, compared to previous years, the price of this technology has dropped significantly, and it’ll continue to decrease over time. So, maybe DNA-based computers will undergo the same transformation as human genome sequencing did earlier. When first developed, sequencing an entire genome cost $2.7 billion. Today, the same process costs less than $1,000. In fact, some genome sequencing cases cost as little as $280.
DNA computers offer enormous potential for the future of computing, but there’s still a lot of work that needs to be done in this field. Although our existing computers serve us well, once they reach their absolute maximum speed and storage capacity, the idea of having a super-efficient computer based on DNA won’t seem so bizarre.