Crowdsurfing motor proteins create nerve-like polymer networks
by Neal Singer
Using a succession of biological mechanisms, Sandia researchers have created linkages of polymer nanotubes that resemble the structure of a nerve, with many outthrust filaments poised to gather or send electrical impulses.
“This is the first demonstration of biomolecular machines assembling complex polymer structures,” says George Bachand (1132).
Creation of the neural structure, unachievable by normal manufacturing techniques, begins by altering the behavior of kinesin motor proteins — biological machines found in every human cell. These tiny motors, portrayed in videographics as a vertical body with two legs, tote cellular matter as they stride along protein microtubules that form the cell structure. In their purposefulness, the motors resemble the enchanted brooms in Disney’s Fantasia, relentlessly carrying buckets of water up the castle stairs.
Turning nature’s machinery on its head, the researchers used known techniques to glue the “shoulders” of kinesin motors to a glass substrate. This prevents their bodies from traveling, but their “legs” above them continue their vigorous movements. These pass microtubules above them like an audience crowdsurfing entertainers on upraised hands.
In the next laboratory step, these traveling protein microtubules, microns in length, encounter relatively large polymer spheres, tens of microns in diameter, inserted by the researchers.
“At that point, we have structures that want to do work — the kinesin-powered microtubules — and something they want to do work on — the spheres,” says co-primary investigator Wally Paxton (1132).
The microtubules, pre-coated with a sticky substance, pinch off polymer nanotubes from the polymer ball that lengthen as the kinesin motors travel on. The process resembles strands of string cheese lengthening as a piece of pizza is removed from a pan, says Wally.
As the nanotubes lengthen and crosslink, they form structures complex enough to bring to mind the lights of a city seen at night from an airplane at high altitude. The networks range from hundreds of micrometers to tens of millimeters in total size and are composed of tubes 30 to 50 nanometers in diameter.
“One goal of our work is to make artificial, highly branched neural structures,” says George. “The next step is, can we wire them together? The answer is, the motors should do it naturally. And two such networks, joined together, would have self-healing built into them. The motors never stop running until they run out of fuel. A neural branch breaks, and then a motor can act on that area to produce a new branch.”
“This is foundational science,” says Wally. “It’s the first time a chemically created network has been arranged by biological means without going through the macrostage of normal manufacture. Now we have a robust artificial network that could communicate with an artificial limb as a prosthetic interface. Currently, we use hard rigid electrodes to penetrate nerve tissue; they cause inflammation. One possibility we see is to use soft structure like those created here to painlessly interface with the body’s nerve structures.”
The insertion of quantum dots also proved stable, which means that light could be used to carry information through the structure as well as electricity.
A paper on the work was published in April in the journal Nanoscale. Other authors were Nathan Bouxsein, Ian Henderson (both 1132), and Andrew Gomez (1815).
The work is supported by DOE’s Office of Basic Energy Sciences and performed in part at its Center for Integrated Nanotechnologies, an Office of Science user facility.-- Neal Singer
Red and White Fleet going green
by Patti Koning
When it comes to environmental sustainability, Red and White Fleet president Tom Escher is all in.
“Everyone is talking about reducing emissions by 20 percent, 40 percent, or more,” he says. “I thought, ‘Why not do away with emissions altogether?’”
Sandia , which recently signed a cooperative research and development agreement with Red and White Fleet, is helping the San Francisco-based company realize that goal. Named SF-BREEZE (San Francisco Bay Renewable Energy Electric vessel with Zero Emissions), the project aims to eventually design, build, and operate a high-speed hydrogen fuel cell passenger ferry and hydrogen refueling station, pending the results of a feasibility study.
Hydrogen fuel cells have several advantages over the diesel engines that power most passenger ferries — no harmful exhaust emissions, higher energy efficiency, quiet operation, and no risk of fuel spills. Replacing diesel engines and generators with hydrogen fuel cells could greatly improve air and water quality in harbor areas.
The hydrogen refueling station is planned to be the largest in the world and serve fuel cell electric cars, buses, and fleet vehicles in addition to the ferry and other maritime vehicles.
The US Department of Transportation’s Maritime Administration is funding the feasibility study to examine the technical, regulatory, and economic aspects of the project.
“The Maritime Administration is committed to finding new and efficient technologies for use in the maritime industry that reduce pollution and protect our environment,” says Maritime Administrator Paul “Chip” Jaenichen. “This industry continues moving forward on renewable energy and clean-fuel options, and this project encourages a shift toward lower-impact maritime fuels that may further green the waterborne link in our national transportation system.”
Sandia is leading the study in partnership with Red and White Fleet, the American Bureau of Shipping, the US Coast Guard, and naval architect Elliott Bay Design Group. Other contributors include the California Environmental Protection Agency’s Air Resources Board and the Governor’s Office of Business and Economic Development.
“We are involving so many stakeholders up front because if the feasibility study shows a ‘go’ we want to make sure the next phase has a rock-solid foundation,” says mechanical engineer Joe Pratt (8367), the Sandia project lead. “We hope the feasibility study, regardless of the outcome, can be useful to others nationally and around the world who are looking at hydrogen fuel cell vessels as clean energy alternatives.”
Boat speed critical to economic viability
Economic viability is essential to the success of SF-BREEZE.
“Rather than a tour boat that would primarily be a demonstration project, Red and White Fleet believes a high-speed passenger ferry makes economic sense,” says Joe. To compete with existing transportation methods — cars, buses, Bay Area Rapid Transit, and other ferries — the ferry must be fast. But speed adds complexity.
“If you are trying to achieve speed, boat weight is important,” Joe says. “Fuel cells and hydrogen are heavier than existing diesel engines and fuel, so the question becomes can you build a boat powered by hydrogen fuel cells that is both large and fast enough? The feasibility study will provide that answer.”
A preliminary conceptual study shows the answer is probably yes, but it will require a boat specially designed to accommodate hydrogen fuel and the fuel cell technology. A traditional passenger ferry can’t easily be retrofitted with a hydrogen fuel cell, so it was essential to include a naval architect in the feasibility study. The ferry design will include collaboration with the American Bureau of Shipping and the Coast Guard to ensure the final design conforms to safety and reliability rules and regulations.
World’s largest hydrogen refueling station
The boat — design, operation, maintenance, and fueling — is one part of the equation; the hydrogen refueling station is the other. The high-speed passenger ferry would use about 1,000 kilograms of hydrogen per day. To put this in perspective, an average hydrogen fuel cell car might use less than 5 kilograms of hydrogen per week.
To support the ferry and other potential users, the refueling station would have a capacity of 1,500 kilograms a day — about twice the size of the largest hydrogen refueling station in the world. It would also be the first hydrogen refueling station to simultaneously serve land and marine uses.
The economy of scale could boost the local hydrogen fuel cell marketplace. “A larger station reduces the cost per kilogram of hydrogen,” says Joe. “Higher use will drive down that cost even more.”
Reducing the cost of hydrogen refueling could stimulate the market for hydrogen fuel cell cars and accelerate wider adoption of the technology in other vehicle markets, such as heavy-duty trucks and buses.
“This project offers an opportunity to closely examine how hydrogen can take its rightful place as a clean, low-carbon fuel for high-volume transportation operations, and also build the business case as part of an innovative application for fuel cells,” says Catherine Dunwoody, chief of the Fuel Cell Program at the California Air Resources Board.
Feasibility study will address regulations
SF-BREEZE will enter new regulatory space, both for the high-speed ferry and refueling station. The feasibility study will examine those regulations and their impact on the project.
For the refueling station, Sandia can draw on its technical expertise in developing and optimizing safe, cost-effective vehicular hydrogen fueling stations. DOE’s Fuel Cell Technologies Office funds most of Sandia’s efforts in this area. Sandia is a leading partner in two nationwide infrastructure initiatives: H2USA, a private-public partnership focused on advancing hydrogen infrastructure, and the Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST), a DOE project established to support H2USA.
“The knowledge, tools, and stakeholder resources we’ve cultivated through these initiatives will directly apply to developing the large, multi-use hydrogen refueling station,” says Joe. “We will work closely with the Air Resources Board and the California Governor’s Office of Business and Economic Development to determine the best location for the refueling station and understand the associated regulations.”
Sandia leads the Maritime Fuel Cell project, which is piloting the use of a hydrogen fuel cell to power refrigerated containers on land and on transport barges at the Port of Honolulu.
“Working with the Bureau of Shipping and the Coast Guard, we’ve explored some of the unique issues related to using a hydrogen fuel cell on a vessel and in the marine environment,” says Joe. “But there is more at stake when the fuel cell is powering the boat, not an auxiliary system, and the boat is carrying passengers.”
Vessel design next step
If the feasibility study indicates that SF-BREEZE could succeed technically, economically, and within regulations, the next step is to design the vessel. The project will need additional funding, resources, and partners, which could come from the federal government, the state of California, investors, industry, or private foundations.
Escher jokes that if the project ultimately succeeds, it could hurt him financially.
“It will make all of my boats obsolete and I’ll have to replace my entire fleet,” he says. “But in all seriousness, this is really about preserving the environment for future generations.”
He hopes to continue Red and White’s tradition of leadership and environmental stewardship established by his grandfather Thomas Crowley, who started the company in 1892.
“I want to ride across the San Francisco Bay on a quiet, fast boat with no emissions,” he says. “If we get thirsty, we can drink the exhaust.”Visit maritime.sandia.gov for more information.
-- Patti Koning
Lab to market: Sandia brings home FLC regional tech transfer awards
by nancy Salem
Sandia won four regional awards from the Federal Laboratory Consortium (FLC) for its work to develop and commercialize innovative technologies. One of them honored business development specialist Bianca Thayer (8539) as Technology Transfer Professional of the Year.
Sandia technologies recognized by the FLC’s Far West/Mid-Continent regions for 2015 are:
- Dynamic Prosthetic Socket System with a Notable Technology Development Award
- Decontamination Technology for Chemical and Biological Agents with an Excellence in Technology Transfer Award
- Twistact with an Outstanding Technology Development Award
The awards will be presented Aug. 26 at the Hilton Airport/Harbor Bay Marina in San Diego, California.
“Sandia is truly honored to be recognized by our peers for our work in technology development and technology transfer,” says Jackie Kerby Moore, manager of Technology and Economic Development Dept. 7933 and Sandia’s representative to the FLC. “Congratulations to the all principal investigators and teams who are being acknowledged for their inspiring accomplishments.”
A passion for tech transfer
Bianca started her Sandia career five years ago as a licensing executive in Albuquerque after working 30 years in industry. She has negotiated new industry and academic partnerships and transferred a wide range of Labs technologies through licensing and cooperative research and development and Work for Others agreements. She also developed the TEDS courses for intellectual property and licensing and has personally trained many technical staff on the value of IP.
Among Bianca’s successes was negotiating the patent license in 2012 with UOP Honeywell for crystalline silico-titanates used to remove radioactive cesium from contaminated seawater following the Fukushima nuclear power plant disaster in Japan. She also negotiated numerous new licenses for Sandia’s decontamination technology resulting in more widespread use of the product.
“Bianca Thayer has been outstanding to work with on technology transfer,” says Mark Rigali (6224). “Her understanding of the mindset of our business partners and the nature of technology being licensed made the tech transfer effort smooth and almost effortless. She’s really good at what she does and makes it look easy when it’s not.”
Her manager, Carrie Burchard, says Bianca, who transferred to Sandia/California in 2013, “is constantly thinking of new ways to help her licensees be successful in commercializing technologies from Sandia. She’s got a true passion for technology transfer.”
A better prosthesis
The national Amputee Coalition says nearly 2 million people in the United States live with limb loss, and about two-thirds have lost a lower limb. Diabetes is the leading cause, accounting for more than 65,000 amputations a year nationwide.
The fit of a prosthesis is a challenge for amputees because fluid in the leg shifts and muscles shrink while walking on an artificial leg. A custom-fit socket doesn’t always fit.
Jason Wheeler (6533) has been studying prosthetics at the Labs for a decade and is part of a robotics group that developed a sensor to tell how a limb changes, along with a system that automatically accommodates those changes.
Jason says Sandia’s sensor is unique because it detects pressure in three directions: normal and two shear forces on the skin. Shear forces cause such problems as rubbing, blisters, and abrasions, but no appropriately sized commercial sensing system can monitor them, he says.
Sandia’s three-axis pressure sensor fits in a liner that slips into the socket of a prosthesis. The system automatically adjusts socket shape by moving fluid into bladders inside the liners that amputees normally wear to improve a socket’s fit and comfort. Since modifying a custom socket would be expensive and cumbersome and could require several fittings, Sandia adapted its technology to fit inside a liner made of elastomeric material similar in thickness to a gel liner.
“With the liner, you just take out your old one and drop in the new one and you’re good to go. That’s a very important component of this technology,” Jason says.
Development continues and more amputee testing is needed, but the technology “is getting mature enough to partner with companies who will commercialize it and make it available to people who need it,” he says. Sandia has applied for patents on the technology.
Sandia decontamination technology neutralizes chemical and biological agents using a mix of mild, nontoxic, and noncorrosive chemicals found in common household products such as hair conditioner and toothpaste. It contains both surfactants, which lift agents off a surface, and mild oxidizers, which break down the agent’s molecules into nontoxic pieces that can be washed down a household drain like detergent or dish soap.
The product works quickly and kills 99.99999 percent of bacteria, viruses, and fungi. Originally used by the military and first responders, Sandia has licensed the formula to companies that have developed it to battle toxic mold and decontaminate meth labs, disinfect healthcare facilities and schools, remove pesticides from farm equipment and agricultural packing plants, and fight the spread of the Ebola virus in Africa. It also has been used as a preventive measure against contaminants at presidential debates and a political convention.
Sandia has promoted the technology, worked with companies to license and commercialize it, and adapted it for new products and uses. Seven new licensees are manufacturing and distributing products based on the Sandia decontamination patents. Efforts continue to add more licensees and product applications.
The decontamination formula was developed with funding from DOE and NNSA Chemical and Biological National Security Program (CBNP).
New approach to an old problem
Sandia’s Twistact technology is designed to take wind energy to the next level. “It can eliminate the need for rare earth magnets in multimegawatt wind turbines, which is the last major hurdle to proliferation of cost-effective wind power,” says principal investigator Jeff Koplow (8366). “Anticipated rare earth supply disruptions are holding back large-scale investment in wind power.”
Twistact also should allow construction of very large wind turbines to achieve better economies of scale that exist at 10 megawatts and beyond, and reduce the weight of wind turbine housings and, potentially, construction costs.
“Twistact is a new approach to the very old problem of how to transmit electrical power between something that moves and something that doesn’t,” Jeff says. “Think of a moving subway train taking power off a stationary third rail.”
It is done now with a sliding contact device, a brush or shoe that rides along a surface. But sliding electrical contacts easily wear out. “Twistact connects an electrical circuit between something moving and something stationary or, in the case of a wind turbine, something rotating and something not, without a sliding contact and without electrical arcing.”
The technology could be important for wind turbines because it makes the use of copper and steel instead of rare earth magnets practical in the generators. “Twistact technology is designed to eliminate the need for high-maintenance components like gear boxes and brush contacts,” Jeff says.
Earlier this year, Twistact was chosen for DOE’s LabCorps entrepreneurship pilot program. Jeff will receive $75,000 to develop commercialization plans for the technology and will get business training and have access to other resources.
The FLC is a nationwide network of more than 300 members that provides a forum to develop strategies and opportunities to link laboratory mission technologies and expertise with the marketplace. Its awards program annually recognizes federal laboratories and their industry partners for outstanding technology transfer efforts. Since established in 1984 the FLC has presented awards to nearly 200 federal laboratories. It is considered one of the most prestigious honors in technology transfer.
“Decon technology, Twistact, and a better-fitting prosthesis are great examples of how Sandia’s scientific research translates into products that benefit the public,” says Pete Atherton, senior manager of Industry Partnerships Dept. 1930. “We look forward to working with partners to make these innovations widely available, and people like Bianca Thayer help make that possible.”
-- nancy Salem