Tag Archives: nanoflowers

Metallic nanoflowers produce neuron-like fractals

I was a bit surprised to find that this University of Oregon story was about a patent. Here’s more from a July 28, 2015 news item on Azonano,

Richard Taylor’s vision of using artificial fractal-based implants to restore sight to the blind — part of a far-reaching concept that won an innovation award this year from the White House — is now covered under a broad U.S. patent.

The patent goes far beyond efforts to use the emerging technology to restore eyesight. It covers all fractal-designed electronic implants that link signaling activity with nerves for any purpose in animal and human biology.

Fractals are objects with irregular curves or shapes. “They are a trademark building block of nature,” said Taylor, a professor of physics and director of the Materials Science Institute at the University of Oregon [UO]. “In math, that property is self-similarity. Trees, clouds, rivers, galaxies, lungs and neurons are fractals. What we hope to do is adapt the technology to nature’s geometry.”

Named in U.S. patent 9079017 are Taylor, the UO, Taylor’s research collaborator Simon Brown, and Brown’s home institution, the University of Canterbury in New Zealand.

A July 28, 2015 University of Oregon news release (also on EurekAlert) by Jim Barlow, which originated the news item, continues the patent celebration,

“We’re very delighted,” Taylor said. “The U.S. Patent and Trademark Office has recognized the novelty and utility of our general concept, but there is a lot to do. We want to get all of the fundamental science sorted out. We’re looking at least another couple of years of basic science before moving forward.”

The patent solidifies the relationship between the two universities, said Charles Williams, associate vice president for innovation at the UO. “This is still in the very early days. This project has attracted national attention, awards and grants.

“We hope to engage the right set of partners to develop the technology over time as the concept moves into potentially vast forms of medical applications,” Williams added. “Dr. Taylor’s interdisciplinary science is a hallmark of the creativity at the University of Oregon and a great example of the international research collaborations that our faculty engage in every day.”

Here’s an image illustrating the ‘fractal neurons’,


Caption: Retinal neurons, outlined in yellow, attach to and follows branches of a fractal interconnect. Such connections, says University of Oregon physicist Richard Taylor, could some day help to treat eye diseases such as macular degeneration. Credit: Courtesy of Richard Taylor

The news release goes on to describe the ‘fractal approach’ to eye implants which is markedly different from the implants entering the marketplace,

Taylor raised the idea of a fractal-based approach to treat eye diseases in a 2011 article in Physics World, writing that it could overcome problems associated with efforts to insert photodiodes behind the eyes. Current chip technology doesn’t allow sufficient connections with neurons.

“The wiring — the neurons — in the retina is fractal, but the chips are not fractal,” Taylor said. His vision, based on research with Brown, is to grow nanoflowers seeded from nanoparticles of metals that self assemble in a natural process, producing fractals that mimic and communicate with neurons.

It is conceivable, Taylor said, that fractal interconnects — as the implants are called in the patent — could be shaped so they network with like-shaped neurons to address narrow needs, such as a feedback loop for the sensation of touch from a prosthetic arm or leg to the brain.

Such implants would overcome the biological rejection of implants with smooth surfaces or those randomly patterned that have been developed in a trial-and-error approach to link to neurons.

Once perfected, he said, the implants would generate an electrical field that would fool a sea of glial cells that insulate and protect neurons from foreign invaders. Fractal interconnects would allow electrical signals to operate in “a safety zone biologically” that avoids toxicity issues.

“The patent covers any generic interface for connecting any electronics to any nerve,” Taylor said, adding that fractal interconnects are not electrodes. “Our interface is multifunctional. The primary thing is to get the electrical field into the system so that reaches the neurons and induces the signal.”

Taylor’s proposal for using fractal-based technology earned the top prize in a contest held by the innovation company InnoCentive. Taylor was honored in April [2015] at a meeting of the White House Office of Science and Technology Policy.

The competition was sponsored by a collaboration of science philanthropies including the Research Corporation for Science Advancement, the Gordon and Betty Moore Foundation, the W.M. Keck Foundation, the Kavli Foundation, the Templeton Foundation and the Burroughs Wellcome Fund.

You can find out more about InnoCentive here. As for other types of artificial eye implants, the latest here is a June 30, 2015 post titled, Clinical trial for bionic eye (artificial retinal implant) shows encouraging results (safety and efficacy).

“Spring is like a perhaps hand,” E. E. Cummings, Harvard, and nano flowers

It’s always a treat to read a news/press/media release that starts with poetry. From the May 16, 2013 Harvard University press release,

“Spring is like a perhaps hand,” wrote the poet E. E. Cummings: “carefully / moving a perhaps / fraction of flower here placing / an inch of air there… / without breaking anything.”

This was written to celebrate the publication of a paper by Wim L. Noorduin and others, from the press release (Note: Links have been removed),

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.

The precipitation of the crystals depends on a reaction of compounds that are diffusing through a liquid solution. The crystals grow toward or away from certain chemical gradients as the pH of the reaction shifts back and forth. The conditions of the reaction dictate whether the structure resembles broad, radiating leaves, a thin stem, or a rosette of petals.

Replicating this type of effect in the laboratory was a matter of identifying a suitable chemical reaction and testing, again and again, how variables like the pH, temperature, and exposure to air might affect the nanoscale structures.

The project fits right in with the work of Joanna Aizenberg, an expert in biologically inspired materials science, biomineralization, and self-assembly, and principal investigator for this research.

Aizenberg is the Amy Smith Berylson Professor of Materials Science at Harvard SEAS, Professor of Chemistry and Chemical Biology in the Harvard Department of Chemistry and Chemical Biology, and a Core Faculty Member of the Wyss Institute for Biologically Inspired Engineering at Harvard.

Here are some details about how the scientists created their ‘flowers, from the press release,

To create the flower structures, Noorduin and his colleagues dissolve barium chloride (a salt) and sodium silicate (also known as waterglass) into a beaker of water. Carbon dioxide from air naturally dissolves in the water, setting off a reaction which precipitates barium carbonate crystals. As a byproduct, it also lowers the pH of the solution immediately surrounding the crystals, which then triggers a reaction with the dissolved waterglass. This second reaction adds a layer of silica to the growing structures, uses up the acid from the solution, and allows the formation of barium carbonate crystals to continue.

“You can really collaborate with the self-assembly process,” says Noorduin. “The precipitation happens spontaneously, but if you want to change something then you can just manipulate the conditions of the reaction and sculpt the forms while they’re growing.”

Increasing the concentration of carbon dioxide, for instance, helps to create ‘broad-leafed’ structures. Reversing the pH gradient at the right moment can create curved, ruffled structures.

Noorduin and his colleagues have grown the crystals on glass slides and metal blades; they’ve even grown a field of flowers in front of President Lincoln’s seat on a one-cent coin.

“When you look through the electron microscope, it really feels a bit like you’re diving in the ocean, seeing huge fields of coral and sponges,” describes Noorduin. “Sometimes I forget to take images because it’s so nice to explore.”

Here’s a link to and a citation for the paper,

Rationally Designed Complex, Hierarchical Microarchitectures by Wim L. Noorduin, Alison Grinthal, L. Mahadevan, and Joanna Aizenberg. Science 17 May 2013: Vol. 340 no. 6134 pp. 832-837 DOI: 10.1126/science.1234621

H/T to the May 17, 2013 news item on Azonano.