4

Beautiful ‘flowers’ self-assemble in a beaker

With the hand of nature trained on a beaker of chemical fluid, the most delicate flower structures have been formed in a Harvard laboratory—and not at the scale of inches, but microns.

These minuscule sculptures, curved and delicate, don’t resemble the cubic or jagged forms normally associated with crystals, though that’s what they are. Rather, fields of carnations and marigolds seem to bloom from the surface of a submerged glass slide, assembling themselves a molecule at a time.

By simply manipulating chemical gradients in a beaker of fluid, Wim L. Noorduin, a postdoctoral fellow at the Harvard School of Engineering and Applied Sciences (SEAS) and lead author of a paper appearing on the cover of the May 17 issue of Science, has found that he can control the growth behavior of these crystals to create precisely tailored structures.

"For at least 200 years, people have been intrigued by how complex shapes could have evolved in nature. This work helps to demonstrate what’s possible just through environmental, chemical changes," says Noorduin.

Read more

Images: [x]

Ancient Roman Nanotechnology —- The Lycurgus Cup

In the 1950’s the British Museum acquired one of the most amazing archaeological finds from Ancient Rome.  The Lycurgus Cup is a beautiful 1,600 year old goblet crafted from glass by the Ancient Romans.  The cup depicts the punishment of Lycurgus, a mythical king who was ensnared in vines for committing evil acts against the Greek god Dionysus.  The craftsmanship and artwork of the cup are certainly amazing on their own. During the age of the Roman Empire the Romans were master glassmakers, producing some of the finest pieces of glassware in history.   However the Lycurgus cup has one incredible property that goes far beyond traditional glassmaking.  When exposed to light, the cup turns from jade green into a bright, glowing red color.  For decades historians, archaeologists, and scientists had no idea why this occurred or how the Romans made the cup with such light changing properties.  Then in 1990 a small fragment of the cup was examined by scientists under a microscope.  What they discovered is truly amazing.

The Lycurgus cup is not only made of glass, but is impregnated with thousands of small particles of gold and silver.  Each of the gold and silver particles are less than 50 nano-meters in diameter, less than one-one thousandth the size of a grain of table salt.  When the cup is hit with light, electrons belonging to the metal flecks vibrate in ways that alter the color depending on the observer’s position.  What is even more amazing is that the addition of the particles to the glass was no accident or coincidence.  The Romans would have had to have known the exact mixture and density of particles needed to give the cup light changing properties.  This would have been done without the aid of a microscope, without the knowledge of atomic theory, and 1,300 years before Newton’s Theory of Colors.

Today the Lycurgus Cup has profound affects on modern nanotechnology.  After studying the cup, researchers and engineers are looking to adapt the technology for modern purposes.  A researcher from the University of Illinois named Gong Gang Liu is currently working on a device which uses the same technology to diagnose disease.  Another application of the technology is a possible device which can detect dangerous materials being smuggled onto airplanes by terrorists.  

The legacy of Ancient Rome continues.  Arena’s, baths, arches, and  nanotechnology. 

Toy chest?

The size of a speck of dust, this tiny box folded up all on its own when heated. Such an autonomous process is known as “self-assembly,” in which unorganized components form an organized structure solely through interaction with one another, with no outside direction. In this case, the researchers developed a 2-D pattern for a 3-D cube, using different metals for the “walls” than for the corners or “hinges.” When heated, the hinges balled up and in doing so pulled the walls of the pattern together, forming the box.

Credit: MRS

Making a Mini Mona Lisa

The world’s most famous painting has now been created on the world’s smallest canvas. Researchers at the Georgia Institute of Technology have “painted” the Mona Lisa on a substrate surface approximately 30 microns in width – or one-third the width of a human hair. The team’s creation, the “Mini Lisa,” demonstrates a technique that could potentially be used to achieve nanomanufacturing of devices because the team was able to vary the surface concentration of molecules on such short-length scales.

Read More.

This Week in Science - August 5 - 11, 2013:

  • Lab grown burger here.
  • Curiosity’s one year anniversary here.
  • Growing ears here.
  • Mini Mona Lisa here.
  • Giant skull in Potomac here.
  • Scottish astronomical calendar here.
  • Alcohol from coffee grounds here.
  • Henrietta Lacks family & NIH agreement here.
  • Lasers inserting DNA into cells here.
  • Successful malaria vaccine here.
  • Pink planet challenging theories here.
  • European fish hunting water insect here.

How Nanotechnology Could Reengineer Us

from Keithly:

Nanotechnology is an important new area of research that promises significant advances in electronics, materials, biotechnology, alternative energy sources, and dozens of other applications. The graphic below illustrates, at a personal level, the potential impact on each of us. And where electrical measurement is required, Keithley instrumentation is being used in an expanding list of nanotechnology research and development settings.

[source]

5

Mary, Mary, quite contrary, how does your nanogarden grow?

Harvard engineer Wim Noorduin has a green thumb. Only his thumb is only a few microns wide. By carefully controlling gradients of chemicals, he guided the construction of flower-like crystal structures to match their larger biological forms. It’s certainly art, but it also demonstrates a masterful manipulation of chemistry on the nano scale.

Just how small are they? As NPR reports, these flowers could fit in the lapel of the tiny Abraham Lincoln statue on the back of a penny (back when pennies had the Lincoln Memorial on them, anyway). These electron microscope images are false colored to recreate fantastic flowers, and these manipulations will one day help control the construction of useful microstructures. 

If you’re seriously engineering-inclined, here’s the original research as it appears in Science.

4

Viral Membrane Protects Medical Nanorobots From Immune System

Scientists say they have developed a cloaking device to spirit medical nanorobots of the future past immune systems into diseased cells. Their innovation comes from stealing a powerful weapon viruses wield to infect their hosts.

Some viruses wrap themselves in a protective membrane to avoid detection by their host’s immune system and enter cells they are trying to infect. A team at Harvard’s Wyss Institute for Biologically Inspired Engineering have been able to construct their own version of a viral membrane.

Read More

Tiny, Logical Robots Injected into Cockroaches

Nanotechnology just got a little bit smarter.

At the Institute of Nanotechnology and Advanced Materials at Israel’s Bar-Ilan University, Ido Bachelet led a team of scientists in building tiny robots that can respond to chemical cues and operate inside a living animal. More than that, they can operate as logic gates, essentially acting as real computers.

That gives the nanobots — on the order of nanometers, or one-billionth of a meter — the ability to follow specific instructions, making them programmable. Such tiny robots could do everything from target tumors to repair tissue damage.

The experimenters used a technique called “DNA origami” to make the robots. DNA comes in a double-helix shape, making long strings. And like yarn, the strings can be linked together to make different shapes. In this case, the researchers knitted together DNA into a kind of folded box with a lid, a robot called an “E” for “effector.” The “lid” opened when certain molecules bumped into it.

This 1,600-Year-Old Goblet Shows that the Romans Were Nanotechnology Pioneers

image

The colorful secret of a 1,600-year-old Roman chalice at the British Museum is the key to a super­sensitive new technology that might help diagnose human disease or pinpoint biohazards at security checkpoints.

The glass chalice, known as the Lycurgus Cup because it bears a scene involving King Lycurgus of Thrace, appears jade green when lit from the front but blood-red when lit from behind—a property that puzzled scientists for decades after the museum acquired the cup in the 1950s. The mystery wasn’t solved until 1990, when researchers in England scrutinized broken fragments under a microscope and discovered that the Roman artisans were nanotechnology pioneers: They’d impregnated the glass with particles of silver and gold, ground down until they were as small as 50 nanometers in diameter, less than one-thousandth the size of a grain of table salt. Read more.

Scientists Create World’s Tiniest Bunny Using New 3D Shaping Material

"Scientists in Japan recently used a promising new 3D printing material to create objects so small that they are the size as a single bacteria. The researchers were able print shapes that are measured in mere micrometers, including the world’s tiniest rabbit. While the demonstration may be playful, the application certainly isn’t – this new technology may someday be used to print cells and micro-electrodes for medical purposes.”

New Ultrathin, Sticky Coating Prevents Infection From Burns

image

by Michael Keller

Scientists report they have made a new wound dressing for burn victims that can coat even the toughest nooks and crannies to prevent infection. 

Using a biodegradable polyester called poly(L-lactic acid), or PLLA, chemist Yosuke Okamura has developed a sticky coating called nanosheets that can be applied to any part of the body without adhesive. The nanosheet is like plastic wrap and forms a barrier that bacteria can’t penetrate to infect a patient.

“The nanosheets can adhere not only to flat surfaces, but also to uneven and irregular surfaces without adding any adhesives,” Okamura said.

image

Read More

3
Advanced ‘artificial skin’ senses touch, humidity, and temperature

-

Technion-Israel Institute of Technology scientists have discovered how to make a new kind of flexible sensor that one day could be integrated into “electronic skin” (e-skin) — a covering for prosthetic limbs that would allow patients to feel touch, humidity, and temperature.

Current kinds of e-skin detect only touch, but the Technion team’s invention “can simultaneously sense touch (pressure), humidity, and temperature, as real skin can do,” says research team leader Professor Hossam Haick.

Additionally, the new system “is at least 10 times more sensitive in touch than the currently existing touch-based e-skin systems.

Researchers have long been interested in flexible sensors, but have had trouble adapting them for real-world use Haick says. A flexible sensor would have to run on low voltage (so it would be compatible with the batteries in today’s portable devices), measure a wide range of pressures, and make more than one measurement at a time, including humidity, temperature, pressure, and the presence of chemicals. These sensors would also have to be able to be manufactured quickly, easily, and cheaply.

The Technion team’s sensor has all of these qualities, Haick says. The secret: monolayer-capped gold nanoparticles that are only 5–8 nanometers in diameter, surrounded by connector molecules called ligands.

“Monolayer-capped nanoparticles can be thought of as flowers, where the center of the flower is the gold or metal nanoparticle and the petals are the monolayer of organic ligands that generally protect it,” says Haick.

The team discovered that when these nanoparticles are laid on top of a substrate — in this case, made of PET (flexible polyethylene terephthalate), the same plastic found in soda bottles — the resulting compound conducted electricity differently depending on how the substrate was bent.

The bending motion brings some particles closer to others, increasing how quickly electrons can pass between them. This electrical property means that the sensor can detect a large range of pressures, from tens of milligrams to tens of grams. And by varying how thick the substrate is, as well as what it is made of, scientists can modify how sensitive the sensor is. Because these sensors can be customized, they could in the future perform a variety of other tasks, including monitoring strain on bridges and detecting cracks in engines. “The sensor is very stable and can be attached to any surface shape while keeping the function stable,” says Dr. Nir Peled, Head of the Thoracic Cancer Research and Detection Center at Israel’s Sheba Medical Center, who was not involved in the research. (via Advanced ‘artificial skin’ senses touch, humidity, and temperature | KurzweilAI)

Text
Photo
Quote
Link
Chat
Audio
Video