Tag Archives: Florida State University

Synthesizing spider silk

Most of the research on spider silk and spider webs that’s featured here is usually from the Massachusetts Institute of Technology (MIT) and, more specifically, from professor Markus J. Buehler. This May 28, 2015 news item on ScienceDaily, which heralds the development of synthetic spider silk, is no exception,

After years of research decoding the complex structure and production of spider silk, researchers have now succeeded in producing samples of this exceptionally strong and resilient material in the laboratory. The new development could lead to a variety of biomedical materials — from sutures to scaffolding for organ replacements — made from synthesized silk with properties specifically tuned for their intended uses.

The findings are published this week in the journal Nature Communications by MIT professor of civil and environmental engineering (CEE) Markus Buehler, postdocs Shangchao Lin and Seunghwa Ryu, and others at MIT, Tufts University, Boston University, and in Germany, Italy, and the U.K.

The research, which involved a combination of simulations and experiments, paves the way for “creating new fibers with improved characteristics” beyond those of natural silk, says Buehler, who is also the department head in CEE. The work, he says, should make it possible to design fibers with specific characteristics of strength, elasticity, and toughness.

The new synthetic fibers’ proteins — the basic building blocks of the material — were created by genetically modifying bacteria to make the proteins normally produced by spiders. These proteins were then extruded through microfluidic channels designed to mimic the effect of an organ, called a spinneret, that spiders use to produce natural silk fibers.

A May 28, 2015 MIT news release (also on EurekAlert), which originated the news item, describes the work in more detail,

While spider silk has long been recognized as among the strongest known materials, spiders cannot practically be bred to produce harvestable fibers — so this new approach to producing a synthetic, yet spider-like, silk could make such strong and flexible fibers available for biomedical applications. By their nature, spider silks are fully biocompatible and can be used in the body without risk of adverse reactions; they are ultimately simply absorbed by the body.

The researchers’ “spinning” process, in which the constituent proteins dissolved in water are extruded through a tiny opening at a controlled rate, causes the molecules to line up in a way that produces strong fibers. The molecules themselves are a mixture of hydrophobic and hydrophilic compounds, blended so as to naturally align to form fibers much stronger than their constituent parts. “When you spin it, you create very strong bonds in one direction,” Buehler says.

The team found that getting the blend of proteins right was crucial. “We found out that when there was a high proportion of hydrophobic proteins, it would not spin any fibers, it would just make an ugly mass,” says Ryu, who worked on the project as a postdoc at MIT and is now an assistant professor at the Korea Advanced Institute of Science and Technology. “We had to find the right mix” in order to produce strong fibers, he says.

The researchers made use of computational modelling to speed up the process of synthesizing proteins for synthetic spider silk, from the news release,

This project represents the first use of simulations to understand silk production at the molecular level. “Simulation is critical,” Buehler explains: Actually synthesizing a protein can take several months; if that protein doesn’t turn out to have exactly the right properties, the process would have to start all over.

Using simulations makes it possible to “scan through a large range of proteins until we see changes in the fiber stiffness,” and then home in on those compounds, says Lin, who worked on the project as a postdoc at MIT and is now an assistant professor at Florida State University.

Controlling the properties directly could ultimately make it possible to create fibers that are even stronger than natural ones, because engineers can choose characteristics for a particular use. For example, while spiders may need elasticity so their webs can capture insects without breaking, those designing fibers for use as surgical sutures would need more strength and less stretchiness. “Silk doesn’t give us that choice,” Buehler says.

The processing of the material can be done at room temperature using water-based solutions, so scaling up manufacturing should be relatively easy, team members say. So far, the fibers they have made in the lab are not as strong as natural spider silk, but now that the basic process has been established, it should be possible to fine-tune the materials and improve its strength, they say.

“Our goal is to improve the strength, elasticity, and toughness of artificially spun fibers by borrowing bright ideas from nature,” Lin says. This study could inspire the development of new synthetic fibers — or any materials requiring enhanced properties, such as in electrical and thermal transport, in a certain direction.

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

Predictive modelling-based design and experiments for synthesis and spinning of bioinspired silk fibres by Shangchao Lin, Seunghwa Ryu, Olena Tokareva, Greta Gronau, Matthew M. Jacobsen, Wenwen Huang, Daniel J. Rizzo, David Li, Cristian Staii, Nicola M. Pugno, Joyce Y. Wong, David L. Kaplan, & Markus J. Buehler. Nature Communications 6, Article number: 6892 doi:10.1038/ncomms7892 Published 28 May 2015

This paper is behind a paywall.

My two most recent (before this one) postings about Buehler’s work are an August 5, 2014 piece about structural failures and a June 4, 2014 piece about spiderwebs and music.

Finally, I recognized one of the authors, Nicola Pugno from Italy. He’s been mentioned here more than once in regard to his biomimicry work which has often been focused on geckos and their adhesive qualities as per this April 3, 2014 post announcing his book ‘An Experimental Study on Adhesive or Anti-Adhesive, Bio-Inspired Experimental Nanomaterials‘ (co-authored with Emiliano Lepore).

Buckypaper technology in Florida (US) receives $!.4M grant

Just after suggesting (as per my Nov. 26, 2013 posting) that Florida is quietly becoming a center for nanotechnology efforts in the US, there’s a $1.4M funding announcement for Florida State University’s High-Performance Materials Institute (HPMI. From the Nov. 27, 2013 news item on Nanowerk,

Florida State researchers have been awarded more than $1.4 million from the National Science Foundation to develop a system that will produce large amounts of a state-of-the-art material made from carbon nanotubes that researchers believe could transform everything from the way airplanes are built to how prosthetic limbs fit the human body.

“The goal is clear — to show industry the ability to use this in large-scale quantities,” said Richard Liang, director of FSU’s High-Performance Materials Institute (HPMI) and a professor for the FAMU-FSU College of Engineering. “We’re looking at a more efficient, cost effective way to do this.”

The Nov. 26, 2013 Florida State University (FSU) news release (also on EurekAlert), which originated the news item, provides greater detail about buckypaper, the team’s research work, and the team’s hopes for this grant,

The material, buckypaper, is a feather-light sheet made of carbon nanotubes that is being tested in electronics, energy, medicine, space and transportation.  The aviation industry, for example, is doing tests with buckypaper, and it’s projected that it could replace metal shielding in the Boeing 787, currently made up of 60 miles of cable.

Engineers believe that replacing the cable with buckypaper could reduce the weight of the Boeing 787 by as much as 25 percent.

Florida State researchers have been engaged in other projects with buckypaper as well, including the use of the material in creating more advanced and comfortable prosthetic sockets for amputee patients and multifunctional lightweight composites for aerospace applications.

As revolutionary as buckypaper technology is, a major hurdle for its future use is that it can take two or more hours and can cost as much as $500 to make just a small 7-inch by 7-inch piece.  Companies like Boeing need large amounts of it to use on an aircraft.

However, the current process is neither fast nor cheap.

So, Liang will spend the next four years developing a process to produce large-scale amounts of buckypaper. The process and materials would then be patented and marketed to meet the demands of the industrial partners.

Liang will be joined on the project by Arda Vanli, an HPMI researcher and an assistant professor in the Department of Industrial and Manufacturing Engineering, as well as researchers from Georgia Institute of Technology.

The US National Science Foundation (NSF) webpage listing the award describes the specific research being undertaken and introduces the term ‘Bucky-tapes’,

Award Abstract #1344672
SNM: Roll-to-Roll Manufacturing of High Quality Bucky-tape with Aligned and Crosslinked Carbon Nanotubes Through In-line Sensing and Control

Carbon nanotubes (CNTs) demonstrate amazing properties; however, currently only a fraction of these properties can be transferred into products that can be used by engineers and consumers. To effectively transfer CNTs? properties into useful products requires a method to efficiently align and covalently interconnect the CNTs into tailored architectures at the nanoscale. This project will establish the fundamental understanding and foundation for using CNTs to make thin sheet materials, called Bucky-tapes, which can be rapidly produced in roll form and scaled-up for industrial applications. The proposed method will use a modified die-casting manufacturing process utilizing the self-repelling effects of selected flow media. In-situ ultra-violet (UV) reaction chemistry can covalently interconnect the CNTs rapidly to improve the load transfer and thermal and electronic transport properties of CNT networks. In-line multi-stage stretching of the web could orient the randomly dispersed interconnected CNT networks into specific patterns to provide greater strength and optimized transport properties. In-line Raman spectra monitoring and multistage process models will provide affordable, closed loop quality control and variation reduction methods for a high quality consistent nanomanufacturing process. A prototype will be built to demonstrate the continuous roll-to-roll process for manufacturing strong Bucky-tapes with high electrical and thermal conductivity, and low manufacturing cost.

This project can transform CNT thin films networks from a lab-scale demonstration material into commercially viable products with superior properties potentially surpassing the state-of-the-art carbon fiber material. The continuous Bucky-tapes can lead to new materials applications in aerospace, electronics, energy, medicine, and transportation. For example, continuous Bucky-tape could replace metal shielding of 60 miles of cables in the Boeing 787 and reduce cable weight by 25%. The education and outreach plan will expose especially under-represented students to molecular design, nanomanufacturing process development and quality control, structure-property relationship studies. Application oriented materials-by-design and nanomanufacturing process development will motivate students into nanotechnology, manufacturing and new materials development.

I had mentioned this team’s work on buckypaper (or are they now calling it Bucky-tape?) in an Oct. 4, 2011 posting which features a video about buckypaper and in which I noted the possible applications for buckypaper closely mirror those for CNC (cellulose nanocrystals) or, as it’s also known,  NCC (nanocrystalline cellulose).

You can check out Florida State University’s High Performance Materials Institute here.

Where do buckyballs come from?

I’ve always wondered where buckyballs come from (as have scientists for the last 25 years) and now there’s an answer of sorts  (from the July 31, 2012 Florida State University news release Note: I have removed some links),

“We started with a paste of pre-existing fullerene molecules mixed with carbon and helium, shot it with a laser, and instead of destroying the fullerenes we were surprised to find they’d actually grown,” they wrote. The fullerenes were able to absorb and incorporate carbon from the surrounding gas.

By using fullenes  that contained heavy metal atoms in their centers, the scientists showed that the carbon cages remained closed throughout the process.

“If the cages grew by splitting open, we would have lost the metal atoms, but they always stayed locked inside,” Dunk [Paul Dunk, a doctoral student in chemistry and biochemistry at Florida State and lead author of the study published in Nature Communications] noted.

The researchers worked with a team of MagLab chemists using the lab’s 9.4-tesla Fourier transform ion cyclotron resonance mass spectrometer to analyze the dozens of molecular species produced when they shot the fullerene paste with the laser. The instrument works by separating molecules according to their masses, allowing the researchers to identify the types and numbers of atoms in each molecule. The process is used for applications as diverse as identifying oil spills, biomarkers and protein structures.

Dexter Johnson in his Aug. 6, 2012 posting on the Nanoclast blog on the IEEE (Institute of Electrical and Electronics Engineers) provides some context and commentary (Note: I have removed a link),

When Richard Smalley, Robert Curl, James Heath, Sean O’Brien, and Harold Kroto prepared the first buckminsterfullerene (C60) (or buckyball), they kicked off the next 25 years of nanomaterial science.

Here’s an artist’s illustration of  what these scientists have achieved, fullerene cage growth,

An artist’s representation of fullerene cage growth via carbon absorption from surrounding hot gases. Some of the cages contain lanthanum metal atoms. (Image courtesy National Science Foundation) [downloaded from Florida State University website]

 As I noted earlier I’m not alone in my fascination (from the news release),

Many people know the buckyball, also known by scientists as buckminsterfullerene, carbon 60 or C60, from the covers of their school chemistry textbooks. Indeed, the molecule represents the iconic image of “chemistry.” But how these often highly symmetrical, beautiful molecules with  fascinating properties form in the first place has been a mystery for a quarter-century. Despite worldwide investigation since the 1985 discovery of C60, buckminsterfullerene and other, non-spherical C60 molecules — known collectively as fullerenes — have kept their secrets. How? They’re born under highly energetic conditions and grow ultra-fast, making them difficult to analyze.

“The difficulty with fullerene formation is that the process is literally over in a flash — it’s next to impossible to see how the magic trick of their growth was performed,” said Paul Dunk, a doctoral student in chemistry and biochemistry at Florida State and lead author of the work.

There’s more than just idle curiosity at work (from the news release),

The buckyball research results will be important for understanding fullerene formation in extraterrestrial environments. Recent reports by NASA showed that crystals of C60 are in orbit around distant suns. This suggests that fullerenes may be more common in the universe than previously thought.

“The results of our study will surely be extremely valuable in deciphering fullerene formation in extraterrestrial environments,” said Florida State’s Harry Kroto, a Nobel Prize winner for the discovery of C60 and co-author of the current study.

The results also provide fundamental insight into self-assembly of other technologically important carbon nanomaterials such as nanotubes and the new wunderkind of the carbon family, graphene.

H/T to Nanowerk’s July 31, 2012 news item titled, Decades-old mystery how buckyballs form has been solved. In addition to Florida State University, National High Magnetic Field Laboratory (or MagLab), the CNRS  (Centre National de la Recherche Scientifique)Institute of Materials in France and Nagoya University in Japan were also involved in the research.

Buckypaper and nanocrystalline cellulose; two different paths to the same ends?

Buckypaper interests me largely because of its name (along with Buckyballs and Buckytubes [usually called carbon nanotubes]). I believe the names are derived from Buckminsterfullerenes a form of carbon engineered (it can be found in nature) in the labs at Rice University. From the Wikipedia essay on Buckminsterfullerenes,

Buckminsterfullerene is a spherical fullerene molecule with the formula C60. It was first prepared in 1985 by Harold Kroto, James Heath, Sean O’Brien, Robert Curl and Richard Smalley at Rice University.  Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of buckminsterfullerene and the related class of molecules, the fullerenes. The name is an homage to Richard Buckminster Fuller, whose geodesic domes it resembles. Buckminsterfullerene was the first fullerene molecule discovered and it is also the most common in terms of natural occurrence, as it can be found in small quantities in soot.

Buckypaper is a main focus at the High Performance Materials Institute at the Florida State University, which has just *released a promotional video (according to the Oct. 3, 2011 news item on Nanowerk). Here’s the video,

It reminds me a little of the video for Nokia’s Morph concept, which was released a few years back. I haven’t heard any substantive news about that project although there are the occasional updates. For example, the Morph was originally described it as a phone and then they changed it to the Morph concept. I’d love to see a prototype one of these days. (There’s more about the Morph and its incarnations in my Sept. 29, 2010 posting.)

The descriptions for applications using Buckypaper reminded me of nanocrystalline cellulose as I’ve seen some of the same claims made for that substance. I’m hoping to hear about the new plant in Windsor, Québec which is supposed to be opening this fall. From the ArboraNano new projects page,

Currently, Canada has an 18- to 24-month global lead in the commercial production of NCC as a 1 ton/day demonstration plant located in Windsor, Quebec enters the final phases of construction. Startup is planned for Fall 2011.

It’s good to see all these different research efforts and to reflect on the innovation being demonstrated.

* Nov. 27, 2013: changed ‘release’ to ‘released’.