Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Purdue simulation to help merge molecules with silicon electronics

Purdue simulation to help merge molecules with silicon electronics

August 18, 2005

WEST LAFAYETTE, Ind. - Engineers at Purdue University have created a nanotech simulation tool that shows how current flows between silicon atoms and individual molecules to help researchers design "molecular electronic" devices for future computers and advanced sensors.

Molecular electronics could make it possible to manufacture hardware by "growing" circuits and devices in layers that may "self-assemble," similar to the growth of structures in living organisms. Devices for a variety of applications might be fabricated using techniques based on chemical attractions rather than the complex, expensive processes now used to etch electronic circuits.




One challenge, however, in developing molecular electronics is to better understand how electricity is conducted between molecules and silicon contacts connecting various devices in a circuit, said Geng-Chiau Liang, a postdoctoral research assistant in Purdue's School of Electrical and Computer Engineering.

Researchers will be able to use the new simulation tool to see precisely how electrical conductivity changes depending on how molecules are connected to silicon, information that is critical to properly design the devices.

"I believe we might be one of the first theorists who have created a tool to show how electricity is conducted between molecules and silicon at the atomic level," said Avik Ghosh, a research scientist in electrical and computer engineering who worked with Liang.

Details about the simulation tool are appearing in the current issue (Aug. 12, Volume 95, Issue 7) of the journal Physical Review Letters. The paper was written by Liang and Ghosh. The research has been funded through two national centers based at Purdue's Discovery Park, the university's hub for interdisciplinary research.

Scientists and engineers are working to develop techniques for creating future computers, sensors and other devices that use molecules, such as proteins and DNA, instead of conventional electronic components. The concept may spawn new "biochips" that will use proteins in sensors for detecting contaminants and pollutants in the air and water and for analyzing the blood and biological samples.

"The idea is that molecules might be able to complement or supplement silicon," Ghosh said. "All traditional research in molecular electronics has focused on combining molecules with metal contacts, but we've been studying the interaction of molecules and silicon instead of metals because the computer industry is built on semiconductors, which is silicon."

Liang and Ghosh used the tool to show how current flows between silicon atoms and molecules called buckminsterfullerenes, or "buckyballs."

Named after architect R. Buckminster Fuller, who designed the geodesic dome, buckyballs are soccer-ball-shaped molecules containing 60 carbon atoms. A buckyball has a width of about 1 nanometer, or one-billionth of a meter, which is roughly 10 atoms wide.

"This paper is a proof of concept showing that our theory is at a point that we can actually look at experiments and explain them quantitatively," Liang said. "We have shown how the conductance of electricity changes when you change the type of bond connecting buckyballs to silicon."

The researchers used their computational model to predict how electricity flows when buckyballs and silicon are connected in three ways. In one case, there is no chemical bond - the buckyball is simply sitting on top of the silicon. In another case, the molecule has been connected to silicon by annealing, or heating, the silicon. And in the third case, the buckyball is resting inside of a tiny pit, a natural defect existing in the silicon.

The model precisely plotted how conduction and voltage changed in the three types of connections, and those predictions agreed with experimental data from other researchers who measured the actual changes in current flow in laboratories.

"Because our predictions agreed with actual experimental data, we know they are accurate," Ghosh said. "This means you can use the model to give theoretical guidance to experiments instead of using strictly a trial-and-error approach."

Together with Supriyo Datta, the Thomas Duncan Distinguished Professor of Electrical and Computer Engineering at Purdue, and his students, Liang and Ghosh developed the mathematical theory on which the model is based. The researchers used a Purdue supercomputer to develop and test the simulation.

The Purdue engineers used buckyballs in their simulation because the molecules are well-known in the scientific community and data are readily available. The tool, however, could be used to simulate conduction using any molecule connected to silicon.

"Researchers want to know what kind of molecule can provide specific conduction characteristics, and they can substitute other molecules for buckyballs," Liang said. "What we can now do is theoretically explain the experiments in quantitative detail, which is really important for any technology.

"To do this, you must have an atomistic understanding of current flow - basically, how does electricity conduct at the atomic level.\\\

Purdue University



Related Silicon Current Events and Silicon News Articles Silicon Current Events and Silicon News RSS Silicon Current Events and Silicon News RSS
Empa scientists synthesize graphene-like material
Two-dimensional carbon layers, so-called graphenes, are regarded as a possible substitute for silicon in the semiconductor industry.

UCLA researchers create 'fly paper' to capture circulating cancer cells
Just as fly paper captures insects, an innovative new device with nano-sized features developed by researchers at UCLA is able to grab cancer cells in the blood that have broken off from a tumor.

New study confirms exotic electric properties of graphene
First, it was the soccer-ball-shaped molecules dubbed buckyballs. Then it was the cylindrically shaped nanotubes. Now, the hottest new material in physics and nanotechnology is graphene: a remarkably flat molecule made of carbon atoms arranged in hexagonal rings much like molecular chicken wire.

Small optical force can budge nanoscale objects
With a bit of leverage, Cornell researchers have used a very tiny beam of light with as little as 1 milliwatt of power to move a silicon structure up to 12 nanometers. That's enough to completely switch the optical properties of the structure from opaque to transparent, they reported.

Working together to design robust silicon chips
Designers of high-speed silicon chips have often had to compromise on performance levels for their integrated circuit designs because of physical weaknesses appearing during design verification or even in production.

Understanding mechanical properties of silicon nanowires paves way for nanodevices
Silicon nanowires are attracting significant attention from the electronics industry due to the drive for ever-smaller electronic devices, from cell phones to computers.

New 'finFET' promising for smaller transistors, more powerful chips
Purdue University researchers are making progress in developing a new type of transistor that uses a finlike structure instead of the conventional flat design, possibly enabling engineers to create faster and more compact circuits and computer chips.

Tiny injector to speed development of new, safer, cheaper drugs
It's no bigger than a stamp packet but it has the potential to allow rapid development of a new generation of drugs and genetic engineering organisms, and to better control in-vitro fertilization.

Materials scientists find better model for glass creation
Harvard materials scientists have come up with what they believe is a new way to model the formation of glasses, a type of amorphous solid that includes common window glass.

Rice U. lab leads hunt for new zeolites
In all the world, there are about 200 types of zeolite, a compound of silicon, aluminum and oxygen that gives civilization such things as laundry detergent, kitty litter and gasoline. But thanks to computations by Rice University professor Michael Deem and his colleagues, it appears there are -- or could be -- more types of zeolites than once thought.
More Silicon Current Events and Silicon News Articles
Pinzon 8-Piece Silicon Spatula Set with Stainless-Steel Canister Holder [Amazon Frustration-Free Packaging]

Pinzon 8-Piece Silicon Spatula Set with Stainless-Steel Canister Holder [Amazon Frustration-Free Packaging]
by Amazon

This fabulous set makes a great gift for a cook just realizing the benefits of silicone. A flexible, heat-resistant, colorfully-tinted material, silicone makes the perfect spatula head-it bends smoothly to scoop batter out of bowls, it can scramble eggs in a nonstick frying pan, and it can baste hot roasts. Best of all, silicone utensils go right into the dishwasher for easy cleanup.

This set from Pinzon includes seven utensils: a large spatula, two medium spatulas, two small scrapers, a large spoon-shaped spatula, and a basting brush. The heads are silicone, while the long, smooth handles are hollow stainless steel with hanging holes on the ends. If not hung, the utensils look attractive stored in the brushed stainless-steel, double-walled canister included with the set. The...

Silicon MIX Intensive Hair Deep Treatment 60oz Big Sale!

Silicon MIX Intensive Hair Deep Treatment 60oz Big Sale!
by Avanti Silicon Mix

Silicon Mix Intensive Hair Treatment Hair treatment to restore the health, shine and the softness of dry, damaged and weak hair. DIRECTIONS : Wash hair and towel dry. Apply with massages. Leave on from 2 to 3 minutes depending on the condition of the hair. Rinse. INGREDIENTS : Water, Mineral Oil, Cetyl Alcohol, Stearyl Alcohol, Glycerine, Citric Acid, Cetrimonium Chloride, Dimethycone Copolyol, Cyclomethicone, Keratin, Ceramide, Diazolidinyl Urea (and) Iodopropynyl Butylcarbamate, Fragrance. SIZE : Net Wt. 60 oz / 1,700 g

Silpat 11-5/8-by-16-1/2-Inch Nonstick Silicone Baking Mat

Silpat 11-5/8-by-16-1/2-Inch Nonstick Silicone Baking Mat
by DeMarle

Use on a baking sheet or pan. Made of high quality food grade silicones reinforced with fiberglass mesh.

Silicon

Silicon
by Eberhard Krimmel (Author), P. Siffert (Editor), E.F. Krimmel (Editor)

With topics ranging from epitaxy through lattice defects and doping to quantum computation, this book provides a personalized survey of the development and use silicon, the basis for the revolutionary changes in our lives perhaps best called 'The Silicon Age.' Beginning with the infant days, more than 50 years ago, Silicon reports on all aspects of silicon and silicon technology up to its use in exciting new technologies, including a glance at possible future developments. A team of expert authors, many of them pioneers in the field, have written informative and stimulating contributions that will be of interest to all scientists working with silicon.



Silicon MIX Intensive Hair Deep Treatment 16oz

Silicon MIX Intensive Hair Deep Treatment 16oz
by Avanti Silicon Mix

Silicon Mix Intensive Hair Treatment Hair treatment to restore the health, shine and the softness of dry, damaged and weak hair. DIRECTIONS : Wash hair and towel dry. Apply with massages. Leave on from 2 to 3 minutes depending on the condition of the hair. Rinse. INGREDIENTS : Water, Mineral Oil, Cetyl Alcohol, Stearyl Alcohol, Glycerine, Citric Acid, Cetrimonium Chloride, Dimethycone Copolyol, Cyclomethicone, Keratin, Ceramide, Diazolidinyl Urea (and) Iodopropynyl Butylcarbamate, Fragrance. SIZE : Net Wt. 16 oz / 450 g

Wilton Easy Flex Silicone Baking Cups 12 Count

Wilton Easy Flex Silicone Baking Cups 12 Count
by Wilton

Experience great baking performance with Easy-flex silicone standard Baking Cups. 12 count set fits cavities of a metal muffin pan or can be placed individually on a flat baking pan. Oven, toaster oven, microwave and dishwasher safe. Reusable. Resists

Dap 08781 10.1-Ounce Clear Silicon Plus Premium Silicone Rubber Sealant

Dap 08781 10.1-Ounce Clear Silicon Plus Premium Silicone Rubber Sealant
by Dap

Formulated to create a long lasting watertight seal with superior flexibility and adhesion to a variety of building materials. When cured, it is mold and mildew resistant and will not crack or shrink. Unlike acetoxy silicone sealants. This silicone rubber

Silicon MIX Combination Set big Sale!

Silicon MIX Combination Set big Sale!
by Avanti Silicon Mix

MOISTURIZING SHAMPOO Specially designed for dry, damaged hair. Contains Silicones, Keratin, Ceramides which soften, give strength and shine to hair, plus conditioning agents to protect and replenish your hair's natural moisture SIZE : 473 ml / 16 fl oz Silicon Mix Intensive Hair Treatment Hair treatment to restore the health, shine and the softness of dry, damaged and weak hair SIZE : Net Wt. 36 oz / 1,020 g LISO SEDOSO Intensive Leave-in Hair Shine and Conditioner with SILK PROTEINS Balanced formula rich in Silicones, Keratin, Ceramides and Silk Proteins to condition and provides shine to damaged hair. Works in the internal and external hair structure from roots to ends. Protects against the sun, salted and bleached water and chemical processes. SIZE : 236 ml / 8 fl oz

Pirates of Silicon Valley

Pirates of Silicon Valley
Starring: Anthony Michael Hall, Noah Wyle, Joey Slotnick, J.G. Hertzler, Wayne Pére
Directed By: Martyn Burke
Also With: Martyn Burke (Writer), Joseph Dougherty (Producer), Leanne Moore (Producer), Nick Lombardo (Producer), Steven Haft (Producer), Michael Swaine (Writer), Paul Freiberger (Writer)

The revolution came when we weren't looking. It happened in a garage. In a dorm room. In countless hours of effort, imagining and intrigue. Apple co-founder Steve Jobs and Microsoft co-founder Bill Gates were changing the way the world works, lives and communicates. The event-packed saga of the quirky visionaries who jump-started the future unfolds with exhilarating, cutting-edge style in Pirates of Silicon Valley. Noah Wyle (ER) portrays Jobs and Anthony Michael Hall (The Dead Zone) portrays Gates in this chronicle of the fierce and often humorous battle to rule the fledgling personal computer empire. "The story is almost Shakespearean... it's a tale of lust, greed, ambition, love and hate," writer/director Martyn Burke reflects. And it's a success story unlike any other.

MIU Flexible Cutting Board, Set of 5

MIU Flexible Cutting Board, Set of 5
by MIU France

MIU France 5-Piece polyethylene flexible cutting board, item # 90005. Color coded for different food groups to minimize cross-contamination and to protect countertops. Blue for fish, red for meats, yellow for poultry, green for vegetables and white for general purposes. The flexible boards curl easily to transfer chopped food directly into the bowl, pot or pan. Each board measures 15-inches by 11-inches. Top shelf, dishwasher safe.

© 2009 BrightSurf.com