Making computer transistors from saliva,
milk and blood may be the stuff of Cronenberg films, but it isn’t as
far-fetched as you might think.
Talk about bleeding-edge technology.
Researchers in Israel have managed to build white LEDs and transistors from
nothing biological components – specifically, proteins found in saliva, milk
and blood.
The Mucin protein
in saliva can keep fluorescent dyes of different colours separate in just the
right way for a tri-colour white LED
The idea of blending technology and biology
is nothing new – the term cyborg dates back to 1960 after all, when it was
coined by US researchers Manfred Clynes and Nathan S Kline is an article about
the modifiations that would optimize the human body for space exploration.
However, this work turns our normal thoughts about cyborgs inside out. Instead
of using technology to modify a human, the team at Tel.Aviv University has
taken biological components and used them as the building blocks for
technology.
Instead of using a
complicated industrial system for separating three colours to make a white LED,
the protein does it automatically
Although it sounds like something from a
sci-fi future, the motivation was quite simple: silicon-based computing is
running out. Moore’s law, fabulous as it’s been for the computing industry, is
running into difficulties that can’t be easily solved. Physics is going to get
in the way at some point, and soon.
As EladMentovich, a chemistry PhD student
at Tel Aviv University and part of the research team, says: ‘it’s the great
challenge facing electronics and photonics. The material is getting smaller and
harder to fabricate.’
You know Moore’s Law: the idea that the
number of transistors we can fit on a chip doubles every 18 months, while the
price halves. The trouble is that at today’s dimensions, atoms are already
getting in the way, quantum effects are becoming more than theory, and there’s
the heat too.
So alternatives are being sought. One
avenue of research is quantum computing, which might be a little while coming;
another is spintronics. And taking a leaf out of nature’s book might just be
part of the solution. Mentovich says that the whole idea was to look for
solutions in nature that already exist for problem we’re starting to face in
technology.
Cronenberg’s
Naked Lunch shows how to get a head in technology
‘To make a white LED is quite difficult,’
he begins. You need three colours-red, green and blue-and they must combine,
but not interact with each other. If that happens, you get a colour that’s not
white. Our ambition is to find something biological that can have the same
effect. So we ask: what performs this kind of separation in nature? This is
just what saliva is doing. Saliva sorts food into different groups and then your
body can process it.’
With a little help from the human world of
science (more on that later), the Mucin protein in saliva, which works so well
to begin digestion, can also keep fluorescent dyes of different colours
separate in the right way for a tri-colourwihte LED. And with the addition of
dyes or other chemicals, Mentovich says, the colour of LED it produces can be
controlled.
‘Put three colours into it, and you get
automatic separation. So instead for a very complicated industrial system for
separating three colours, we have a protein that does it naturally,’ he
explains.
Emboldened by its success, the
team-Mentovich along with his colleagues Netta Handler and BogdanBelgorodsky –
decided to look for other useful proteins. And they found one in the blood:
albumin. This protein can absorb oxygen, which means that the researchers can
effectively ‘dope’ the semiconductor with specific chemicals, enabling them to
tailor the material to produce particular technological properties, Mentovich
explains. Milk proteins, meanwhile, form strong fibres that are the basis for
biological transistors.
Using the tissue of living creatures –
cows, pigs and ultimately one day, humans – to create technology creates some
powerful mental images. It conjures up visions of slimy humans plugged into
vast arrays, Matrix – style, and calls to mind Blade Runner and the replicants.
Just the word ‘mucus’ makes us think of the revolting spectacle of David
Cronenberg’s film of Naked Lunch (1991), which saw the protagonist,
exterminator Bill Lee, typing his memoirs into the sticky mouth of a giant
hallucinated insect/typewrites that’s probably spying on him as he struggles to
overcome an addiction to bug spray.
