Tiny Brain-Like Transistor Controls Nanobots

March 12, 2008 by Lisa Zyga weblog
Nano-brain
The wheel-like assembly of 16 duroquinone molecules on the edges and 1 duroquinone molecule in the center can produce "one-to-many" parallel communication. Credit: Bandyopadhyay and Acharya.

For years, researchers have been building tiny nanobots that could one day serve a variety of purposes. But, until now, nanobots couldn't work together.

Recently, scientists Anirban Bandyopadhyay and Somobrata Acharya from the National Institute of Materials Science in Tsukuba, Japan, have built the first ultra-tiny, ultra-powerful "brains" for nanobots.

The brains - just two billionths of a meter across - act as tiny computer transistors. But instead of carrying out just one operation at a time, like a normal transistor, the new devices can simultaneously perform 16 operations at once. In other words, the devices use parallel processing - like the human brain - rather than serial processing - like a normal computer. The researchers call this ability "one-to-many" communication.

The tiny machines are composed of 17 duroquinone molecules that act as logic gates. The researchers arranged 16 of these molecules in a wheel, and placed the last molecule in the middle, which acts as the control center. The entire wheel was constructed on a gold substrate.

Each duroquinone molecule has four side chains that can be independently rotated to represent four separate logic states. Conventional transistors, on the other, have just two logic states: on and off.

To operate the device, the researchers poked the center duroquinone molecule with electrical pulses from the tip of a scanning tunneling microscope. The center molecule is linked to the surrounding 16 molecules by weak hydrogen bonds, so that a pulse to the center molecule can simultaneously transmit instructions to each of the surrounding molecules.

Since each molecule has four side chains, a single pulse to the center molecule can produce one of nearly 4.3 billion (4^16) different states. That compares with a total of 2 (2^1) states that can be produced in a conventional transistor. However, some instructions from the center molecule result in particular arrays of molecules that take on fixed states to maintain equilibrium. But, in principle, the system has 4.3 billion possible states.

Banyopadhyay and Acharya aren´t stopping there, though. The team plans to turn the 2D wheel of 16 molecules into a 3D sphere - a structure that would consist of 1,024 molecules. This spherical device could perform 1,024 instructions at once, theoretically making it capable of 4^1024 different states. The center molecule could be controlled with "handles" that stick out of the core.

The researchers also tested out the 2D nano-brain in their study. They attached the device to eight nanobots (sometimes called "molecular machines"), and demonstrated that the nanobots could respond simultaneously to a single instruction. The ´bots could work together, as if part of a tiny factory.

The scientists also created the "world´s tiniest elevator," a 2-nanometer-tall device that can move up and down by 1 nanometer. They also plan to hook up the brain to a variety of nano-sized motors, propellers, switches, and sensors for different applications.

In the future, the researchers hope that they can control the central duroquinone molecule using proteins or other molecules, rather than the scanning electron microscope tip. For one thing, this ability might enable the brains to serve as tiny transistors packed onto a microchip for future powerful computers.

More futuristically, the brains could accompany nanobots for medical missions, such as bloodless surgery. As the scientists explain, specialized molecular machines could travel through veins to a tumor or damaged tissue, and perform surgery according to the instructions given by the new brains.

More information: Bandyopadhyay, Anirban and Acharya, Somobrata. "A 16-bit parallel processing in a molecular assembly." Proceedings of the National Academy of Sciences. March 11, 2008, vol. 105, no. 10, 3668-3672.

via: The Telegraph

Explore further: Inntags: New tools for innocuous protein tagging

Related Stories

Inntags: New tools for innocuous protein tagging

September 1, 2015

The study, published today at Nature Methods (the most prestigious journal for the presentation of results in methods development), proposes the use of two plant protein epitopes, named inntags, as the most innocuous and ...

Getting picture of molecules in cell in just minutes

August 27, 2015

Understanding exactly what is taking place inside a single cell is no easy task. For DNA, amplification techniques are available to make the task possible, but for other substances such as proteins and small molecules, scientists ...

Recommended for you

For 2-D boron, it's all about that base

September 2, 2015

Rice University scientists have theoretically determined that the properties of atom-thick sheets of boron depend on where those atoms land.

Electrical circuit made of gel can repair itself

August 25, 2015

(Phys.org)—Scientists have fabricated a flexible electrical circuit that, when cut into two pieces, can repair itself and fully restore its original conductivity. The circuit is made of a new gel that possesses a combination ...

An engineered surface unsticks sticky water droplets

August 31, 2015

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets ...

Scientists grow high-quality graphene from tea tree extract

August 21, 2015

(Phys.org)—Graphene has been grown from materials as diverse as plastic, cockroaches, Girl Scout cookies, and dog feces, and can theoretically be grown from any carbon source. However, scientists are still looking for a ...

5 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

NeilFarbstein
1 / 5 (1) Mar 12, 2008
WoW! The possibilities are endless. I'm gunna read that article.
dachpyarvile
not rated yet Mar 13, 2008
We are the Borg... :)
superhuman
5 / 5 (1) Mar 13, 2008
Its nowhere near a brain or even a neuron, just a set of switches.

>Conventional transistors, on the other, have just two logic states: on and off.

wrong, conventional transistors are analog and have as many states as noise allows to tell apart.
AdseculaScientiae
not rated yet Mar 13, 2008
Very nice article:)
guiding_light
5 / 5 (1) Mar 25, 2008
Molecular electronics requires ultaclean, well-controlled environments such as this STM, with no chance of disrupting the weak hydrogen bonds. Real biology, not so clean or well-controlled.

The use of STM means the substrate is conducting (so the electric potential boundary condition is much wider than nanometer scale). It will be different to use this in a floating environment.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.