Bye-Bye Wash and Dry: Scientists are Developing Self-Cleaning Fabrics

"Autumn Laundry", Image by Walter A. Aue

“Autumn Laundry”, Image by Walter A. Aue

It is likely – – or if it isn’t, it should be – – a universal truth that everyone loves clean clothes but no one likes doing the laundry. I have arrived at this conclusion through many years of my own thoroughly unscientific observations in the laundry room in my apartment building. (My other research project is focused upon discovering the origin of the rift in the time and space continuum where stray socks always seem to disappear into in the washers and dryers.)

This ages old situation might be about to change based upon an interesting new development. This story is neither made from whole cloth nor a fabric-ation.

A group of scientists in Australia claim to have discovered a means to keep clothes clean by treating them with nano-size particles of two common metals and then exposing the fabric to sunlight. This could perhaps one day mean an end to washing clothes in the traditional soap and water manner. This research was reported in an article in the April 25, 2016 edition of The Wall Street Journal entitled An End to Laundry? The Promise of Self-Cleaning Fabric, by Rachel Pannett. I will summarize and annotate this story, and then pose several of my own questions about this, well, material.

Dry Cleaning

Rajesh Ramanathan, a postdoctoral fellow at RMIT University in Melbourne, Australia, explained the basic principal being tested: Minute flecks of copper and silver (called nanostructures), are embedded into cotton fabrics that, when exposed to sunlight, generate small amounts of energy “that degrade organic matter ” on the cloth in about six minutes. He and his team are conducting their work at the Ian Potter NanoBioSensing Facility, within RMIT.

The results of their research were recently published in Advanced Materials Interfaces in a paper entitled Surface Plasmon Resonance: Robust Nanostructured Silver and Copper Fabrics with Localized Surface Plasmon Resonance Property for Effective Visible Light Induced Reductive Catalysis (Volume 3, Issue 6, March 23, 2016). The authors, including Dr. Ramanathan, are Samuel R. Anderson, Mahsa Mohammadtaheri, Dipesh Kumar, Anthony P. O’Mullane, Matthew R. Field, and Vipul Bansal.

Dr. Ramanathan characterized the team’s work as being in its early stages and involving “nano-enhanced fabrics” with the “ability to clean themselves”.  The silver and copper do not alter the fabric in any way and remain embedded even when rinsed in water. As a result, their self-cleaning abilities will persist in successive multiple cleanings.

While encouraging no one to get rid of their washing machines just yet, he does believe that his team’s work “lays a strong foundation” for additional advancements in creating “fully self-cleaning textiles”.

Other current research is investigating whether such nano-enhanced fabrics are capable of affecting germs and even whether they can eradicate “superbugs” that resist today’s antibacterials.

To date, the research team has been testing their fabrics with organic dyes and artificial light. Next they are planning experiments with “real world stains” such as ketsup and wine in an effort to measure how long it will take them to “degrade in natural sunlight”. Additional planed testing will be to see how the nanostructures affect odors in the fabrics.

Spin Cycle

However, another scientist named Christopher Sumby, an associate professor in chemistry and physics at the University of Adelaide, expressed his reluctance at talking about self-cleaning fabrics “at this stage”.

Nonetheless, this experimental new process that use silver and copper, are two “commonly used” chemical catalysts and are “relatively cheap”. Two of the challenges currently facing the research team are how to scale up production of these nanostructures and “how to permanently attach them to textiles”. They are using cotton in their work because it has “a natural three-dimensional structure” that enables the nanostructures to embed themselves and absorb light. They have also found that this works well in removing organic stains from polyester and nylon.

Dr. Ramanathan said that a variety of industries, including textile manufacturers, have expressed their interest to his team. He believes that to enable them to commercialize their process, they would need to make sure the nanostructures can “comply with industry standards for clothing and textiles”.

My Questions

  • What would be the measurable benefits to the environment and energy savings if the needs for electric washers and dryers was significantly reduced by self-cleaning fabrics? Should the researchers use this prospect to their advantage in seeking regulatory approval and additional financing?
  • Although using sunlight, which is free and abundant across the entire world, would be the most renewable and environmentally sound source of energy for this, could the process also be extended for use with artificial light (as is currently being used in the team), for instances where sufficient sunlight becomes unavailable due to weather conditions or other environmental factors?
  • Could this process also be adapted to other forms of porous materials such as wood, paper, and plastics? For example, if people go outside for a picnic, could they could theoretically clean up the table, food containers and paper plates just by leaving them in the sun and then reusing them later? This might further cut down on the volumes of these materials being thrown in the trash or else being sent for recycling.
  • What other entrepreneurial opportunities might arise if this process becomes commercialized?

Applying Origami Folding Techniques to Strands of DNA to Produce Faster and Cheaper Computer Chips

"Origami", Image by David Wicks

“Origami”, Image by David Wicks

We all learned about the periodic table of elements in high school chemistry class. This involved becoming familiar with the names, symbols and atomic weights of all of the chemical occupants of this display. Today, the only thing I still recall from this academic experience was when the teacher told us on the first day of class that we would soon learn to laugh at the following:

Two hydrogen atoms walk into a bar and the first one says to the other “I’ve lost my electron”. The other one answers “Are you sure?”. The first one says “I’m positive.”

I still find this hilarious but whatever I recall today about learning chemistry would likely get lost at the bottom of a thimble. I know, you are probably thinking “Sew what”.

Facing the Elements

Besides everyone’s all-time favorites like oxygen and hydrogen that love to get mixed up with each other and most of the other 116 elements, another one stands alone as the foundation upon which the modern information age was born and continues to thrive today. Silicon has been used to create integrated circuits, much more commonly known as computer chips.

This has been the case since they were first fabricated in the late 1950’s. It has remained the material of choice including nearly all the chips running every imaginable one of our modern computing and communication devices. Through major advances in design, engineering and fabrication during the last five decades, chip manufacturers have been able to vastly shrink this circuitry and pack millions of components into smaller squares of this remarkable material.

A fundamental principle that has held up and guided the semiconductor industry, under relentlessly rigorous testing during silicon’s enduring run, is Moore’s Law. In its simplest terms, it states that the number of transistors that can be written onto a chip doubles nearly every two years. There have been numerous predictions for many years that the end of Moore’s Law is approaching and that another substrate, other than silicon, will be found in order to continue making chips smaller, faster and cheaper. This has not yet come to pass and may not do so for years to come.

Nonetheless, scientists and developers from a diversity of fields, industries and academia have remained in pursuit of alternative computing materials. This includes elements and compounds to improve or replace silicon’s extensible properties, and other efforts to research and fabricate entirely new computing architectures. One involves exploiting the spin states of electrons in a rapidly growing field called quantum computing (this Wikipedia link provides a detailed and accessible survey of its fundamentals and operations), and another involves using, of all things, DNA as a medium.

The field of DNA computing has actually been around in scientific labs and journals for several decades but has not gained much real traction as a viable alternative ready to produce computing chips for the modern marketplace. Recently though, a new advance was reported in a fascinating article posted on Phys.org on March 13, 2016, entitled DNA ‘origami’ Could Help Build Faster, Cheaper Computer Chips, provided by the American Chemical Society (no author is credited). I will summarize and annotate it in order to add some more context, and then pose several of my own molecular questions.

Know When to Fold ‘Em

A team of researchers reported that fabricating such chips is possible when DNA is folded and “formed into specific shapes” using a process much like origami, the Japanese art of folding paper into sculptures. They presented their findings at the 251st American Chemical Society Meeting & Exposition held in San Diego, CA during March 13 through 17, 2016. Their paper entitled 3D DNA Origami Templated Nanoscale Device Fabrication, appears listed as number 305 on Page 202 of the linked document.  Their presentation on March 14, 2016, was captured on this 16-minute YouTube video, with Adam T. Woolley, Ph.D. of Brigham Young University as the presenter for the researchers.

According to Dr. Woolley, researchers want to use DNA’s “small size, base-pairing capabilities and ability to self-assemble” in order to produce “nanoscale electronics”. By comparison, silicon chips currently in production contain features 14 nanometers wide, which turn out to be 10 times “the diameter of single-stranded DNA”. Thus, DNA could be used to build chips on a much smaller and efficient scale.

However, the problem with using DNA as a chip-building material is that it is not a good conductor of electrical current. To circumvent this, Dr. Woolley and his team is using “DNA as a scaffold” and then adding other materials to the assembly to create electronics. He is working on this with his colleagues, Robert C. Davis, Ph.D. and John N. Harb, Ph.D, at Brigham Young University. They are drawing upon their prior work on “DNA origami and DNA nanofabrication”.

Know When to Hold ‘Em

To create this new configuration of origami-ed DNA, they begin with a single long strand of it, which is comparable to a “shoelace” insofar as it is “flexible and floppy”. Then they mix this with shorter stand of DNA called “staples” which, in turn, “use base pairing” to gather and cross-link numerous other “specific segments of the long strand” to build an intended shape.

Dr. Woolley’s team is not satisfied with just replicating “two-dimensional circuits”, but rather, 3D circuitry because it can hold many more electronic components. An undergraduate who works with Dr. Woolley named Kenneth Lee, has already build such a “3-D, tube-shaped DNA origami structure”. He has been further experimenting with adding more components including “nano-sized gold particles”. He is planning to add still more nano-items to his creations with the objective of “forming a semiconductor”.

The entire team’s lead objective is to “place such tubes, and other DNA origami structures, at particular sites on the substrate”. As well, they are seeking us use gold nanoparticles to create circuits. The DNA is thus being used as “girders” to create integrated circuits.

Dr. Woolley also pointed to the advantageous cost differential between the two methods of fabrication. While traditional silicon chip fabrication facilities can cost more than $1 billion, exploiting DNA’s self-assembling capabilities “would likely entail much lower startup funding” and yield potentially “huge cost savings”.

My Questions

  • What is the optimal range and variety in design, processing power and software that can elevate DNA chips to their highest uses? Are there only very specific applications or can they be more broadly used in commercial computing, telecom, science, and other fields?
  • Can any of the advances currently being made and widely followed in the media using the CRISPR gene editing technology somehow be applied here to make more economical, extensible and/or specialized DNA chips?
  • Does DNA computing represent enough of a potential market to attract additional researchers, startups, venture capital and academic training to be considered a sustainable technology growth sector?
  • Because of the potentially lower startup and investment costs, does DNA chip development lend itself to smaller scale crowd-funded support such Kickstarter campaigns? Might this field also benefit if it was treated more as an open source movement?

February 19, 2017 Update:  On February 15, 2017, on the NOVA science show on PBS in the US, there was an absolutely fascinating documentary shown entitled The Origami Revolution. (The link is to the full 53-minute broadcast.) It covered many of the today’s revolutionary applications of origami in science, mathematics, design, architecture and biology. It was both highly informative and visually stunning. I highly recommend clicking through to learn about how some very smart people are doing incredibly imaginative and practical work in modern applications of this ancient art.

Google is Giving Away Certain Patents to 50 Startups In Their Latest Effort to Thwart Patent Trolls

"She Runs Neon Fraction of a Second", Image by Wonderlane

“She Runs Neon Fraction of a Second”, Image by Wonderlane

In the highly competitive world of creating, monetizing, defending and challenging tech-based intellectual property, “free” is neither a word often heard nor an offer frequently made.

However, Google has just begun a new program, for a limited time, to give away a certain types of patents they own to an initial group of 50 startups.  This is principally being done in an effort to resist time and resources devouring litigation with “patent trolls“, companies that purchase patents for no other purpose than to litigate infringement claims in their attempts to win monetary judgments. (We first visited this issue in an April 21, 2015 Subway Fold post entitled New Analytics Process Uses Patent Data to Predict Advancements in Specific Technologies.)

The details of this initiative were carried in a most interesting new article on TechCrunch.com posted on July 23, 2015 entitled Google Offers To Give Away Patents To Startups In Its Push Against Patent Trolls by Ingrid Lunden. I will summarize, annotate, and pose some free questions of my own.

In April 2015, Google successfully started a temporary program for companies to offer to sell them (Google) their patents. Then on July 23, 2015, they launched a reciprocal program to give away, at no cost, “non-organic” patents (that is, those purchased by Google from third parties), to startups.

The recipients of these giveaways are required to abide by two primary conditions:

  • They must join the LOT Network for two years.  This is a tech industry association of patent owners dedicated to reducing the volume of patent troll-driven litigation.
  • The patents can only be used defensively to “protect a company against another patent suit”. Thus, the patents cannot be used to bring a case “against another company” or else its ownership “reverts back to Google”.

Kurt Brasch, one of Google’s senior patent licensing managers who was interviewed for the TechCrunch story, expects other members of the LOT Network to start their own similar programs.

For any of the 50 startups to be eligible for Google’s program, another key requirement is that their 2014 revenues must fall between $500,000 and $20 million. Next, if eligibility is determined, within 30 days they will receive “a list of three to five families of patents”, from which they can make their selection. Still, Google “will retain a broad, nonexclusive license to all divested assets”, as these patents might still be important to the company.

For those startups that apply and are determined to be ineligible, Google will nonetheless provide them with access “to its own database of patents”. These are presumed to alas be categorized as “non-organic”. The unselected startups will be able to ask Google to consider “the potential purchase of any such assets”.

Back in April, when Google began their acquisitions of patents, they were approached by many operating companies and patent brokers. Both types of entities told Mr. Brasch about a “problem in the secondary market“. These businesses were looking for an alternative means to sell their patents to Google and Mr. Brasch was seeking a means to assist interested buyers and sellers.

Google eventually purchased 28% of the patents they were offered that the company felt could potentially be used in their own operations. As these patents were added to Google’s patent portfolio, a portion of them were categorized as “non-organic” and, as such, the company is now seeking to give them away.

Both sides of Google’s latest patent initiative demonstrate two important strategic points as the company is now:

  • Taking more action in enabling other tech firms to provide assistance against litigation brought by troll-driven lawsuits.
  • Presenting the company as a comprehensive “broker and portal” for patents matters.

Last week, as another part of this process, Google substantially upgraded the features on its Google Patents Search. This included the addition of search results from both Google Scholar and Google Prior Art Finder.  (For the full details and insights on the changes to these services see Google’s New, Simplified Patent Search Now Integrates Prior Art And Google Scholar, also by Ingrid Lunden, posted on TechCrunch.com on July 16, 2015.)

While both the purchasing and selling operations of Google’s effort to test new approaches to the dynamics of the patent marketplace appear to be limited, they might become more permanent later on depending on the  results achieved. Mr. Brasch also anticipates continuing development of this patent market going forward either from his company or a larger “group of organizations”.  Just as Google has moved into other commercial sector including, among others, “shopping, travel and media”, so too does he expect the appearance of more new and comparable marketplaces.

My own questions are as follows:

  • In addition to opposing patent troll litigation, what other policy, public relations, technical and economic benefits does Google get from their new testbed of marketplace services?
  • What other industries would benefit from Google’s new marketplace? What about pharmaceuticals and medical devices, materials science (see these four recent Subway Fold posts in this category),  and/or automotive and aerospace?
  • Should Google limit this project only to startups? Would they consider a more expansive multi-tiered approach to include different ranges of yearly revenue? If so, how might the selection of patents to be offered and other eligibility requirements be decided?
  • Might there be some instances where Google and perhaps other companies would consider giving away non-organic patents to the public domain and allowing further implementation and development of them to operate on an open source basis? (These 10 Subway Fold posts have variously touched upon open source projects and methods.)

Self-Healing Concrete Due to Soon Enter the Construction Market

"Second Avenue Subway: 96th Street", Image by MTA Photos

“Second Avenue Subway: 96th Street”, Image by MTA Photos

Please see the end of this post below for a related and most interesting December 7, 2016 update on a related new development on an experimental material called programmable cement.

While nearly all new technologies, products and services vigorously try to keep any bugs out, a modern improvement in an ancient technology that nearly everyone in the world still, well, heavily relies upon is based upon deliberately keeping all of its bugs in.

A microbiologist named Henk Jonkers at Delft University of Technology in the Netherlands, has created self-healing concrete involving bugs of a biological rather than electronic nature. The remarkable story of how he has accomplished this was reported in an article on Smithsonianmag.com entitled With This Self-Healing Concrete, Buildings Repair Themselves, by Emily Matchar, posted on June 5, 2015.

I will sum up, annotate and ask a few additional microbe-free questions.

Taking his inspiration from human biology, Jonkers has created this self-healing material by embedding concrete with limestone capsules. When the limestone is activated by “cracks, air or moisture”, it will then produce one of two forms of bacteria plus another compound called calcium lactate. In turn, these bugs will commence reacting with the calcium lactate to convert it to another chemical called calcite which then seals the cracks.

This advance could potentially solve an enduring problem when concrete is used in construction: Micro-cracks that develop later and, over time, may affect the structural integrity of a building. Moreover, further “leakage” like this in a structure can eventually result in a collapse. Jonker’s creation could put a halt this corrosive activity. The two strains of bacteria that emerge from the limestone can potentially remain “dormant for as long as 200 years”. *

Since 2011, Jonkers has been field testing his self-healing concrete on a lifeguard station which is subject to the corrosive forces at the beach. To date, it remains “watertight”.

The material will be brought to market in 2015 in the forms of “self-healing concrete, a repair mortar and a liquid repair medium”, costing between $33US to $44US per square meter. Because of this relatively high expense, it will only be used at first in structures where “leakage and corrosion” are potentially significant factors.  Nonetheless, Jonkers is working on less costly alternatives to his formulation. He also expects to scale up production of his new concrete by mid-2016.

Self-healing concrete mixtures have also been under development elsewhere at the following universities:

  • In the UK at the University of Bath, Cardiff University, also based upon bacteria (details described here)
  • In the US at MIT using “sunlight to activate polymer microcapsules” to fill in cracks (details described here), and
  • At the University of Michigan by embedding microfibers in conjunction with calcium carbonate (details described here)

Another potentially environmental benefit from self-healing concrete might be a reduction in the worldwide amount of energy used to produce concrete. Currently, it generates 5% of all of global carbon emissions and demand for concrete continues to rise as a result of growing urbanization. Thus, the increasing usage of self-healing concrete may lower the demand for the more carbon-emitting production of new concrete.

My questions are as follows:

  • Can added bacteria likewise bring self-healing capabilities to other building materials such as wood, glass, iron, marble and others?
  • In addition to self-healing, are there other beneficial properties that microbes can add to concrete as well as other construction materials?
  • Conversely, can microbes be similarly and safely somehow used in the demolition of buildings and the clearing of the resulting debris?
  • Are there any possible applications of metamaterials, as covered in the April 10, 2015 Subway Fold post entitled The Next Wave in High Tech Materials Science, to concrete formulations?

There is a common expression among software programmers and developers to try to explain instances when end-users find flaws in their work. They will often, half-jokingly, say “It’s not a bug it’s a feature“. In the case of self-healing concrete, it turns out to be both.


*  For a fascinating journey through the several-millennia history of concrete, I very highly recommend Planet Concrete (Prometheus Books, 2011), by Robert Courland. The author has skillfully enlivened and fully engaged his readers in what might otherwise sound like a somewhat dull topic for a book.



December 27, 2016 Update:

A story was posted on Phys.org today entitled Scientists Develop ‘Programmable’ Cement Particles to Attain Enhanced Properties. (No author is credited.) Scientists at Rice University have created a new form of “programmable” cement that, at the microscopic level, forms new shapes that make the resulting hardened product more durable while less porous. In turn, this may result in “stronger  structures that require less concrete”. I highly recommend clicking through for a full read of this fascinating news.

The Next Wave in High Tech Materials Science

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Optical Profilometer Metamaterials, Image by Oak Ridge National Laboratory

Metamaterials are not something used by the United Federation of Planets’ engineers to build the next iteration of the Starship Enterprise (which, btw, would be designated the NCC-1701-F, although some may differ).  Rather, they are materials fabricated in such a manner that they can bend light, sound, radar, radio and seismic waves. The technological implication of applying these materials in antennas, radar, cosmetics and soundproofing may prove to be transformative according to a fascinating article in the March 23, 2015 edition of The New York Times entitled The Waves of the Future May Bend Around Metamaterials, by John Markoff.  I will summarize this, add some links and annotations, and pose some questions.

These substances achieve their remarkable effect by being composed of microscopic “subcomponents” that are smaller than the wavelengths of the types of waves they are engineered to bend in certain ways. That is, they can be used to “manipulate” the waves in designated manners “that do not normally occur”.

Researchers have been developing a variety of metamaterials for the past 15 years. Their work has recently begun yielding some genuine innovations in systems that incorporate these advances in original and innovative ways. Some of these latest developments include:

  • Airbus*and Lamda Guard are about to test a coating on airline windows to deter attempts to blind them with laser pointing devices by someone on the ground. (See NYC Man Charged With Pointing Laser at Aircraft, in the March 15, 2015 edition of The New York Times for a recent case of this here in New York.)
  • Echodyne is working on several types of antennas, radar-based navigation systems and other devices.
  • Evolv Technology is developing airport security systems.
  • Kymeta has partnered with Intelsat to engineer “land-based and satellite-based intelligent antennas”.
  • Dr. Xiang Zhang at the University of California at Berkeley, is working on, among other metamaterials projects, “superlenses” for microscopes that might increase their magnification powers beyond today’s capabilities. He has received inquiries from “military contractors and commercial companies” and even cosmetics companies concerning metamaterials. As well, he and other developers are creating apps for optical computer networks.
  • Professor Vinod Menon and his research team at the City College of New York, in their Laboratory for Nano and Micro Photonics, have demo-ed “light emission from ultrafast-switching LEDs” made from metamaterials. Using this and other related developments may also lead to significantly faster optical computers networks.
  • Menard Construction published a paper in 2013 entitled Seismic Metamaterial: How to Shake Friends and Influence Waves? by S. Brûlé, E.H. Javelaud, S. Enoch and S. Guenneau, where the company successfully tested “a metamaterial grid of empty cylindrical columns bored into soil” in an effort to reduce the effects of a “simulated earthquake”. (The phases in quotes in the last sentence were from the NYTimes article, not the research paper itself.)

The article concludes on a note of great optimism from Professor Zhang about the future of metamaterials. I completely agree. Once these apps and development projects make their way into commercial markets and other scientists and companies from different fields and industries take greater notice, I strongly believe that new forms of metamaterials and their applications will emerge that have not even been imagined yet. Like any dramatically new technology, this will find its applications perhaps in some very unlikely and surprising sectors.

Just to start off, what about medical devices, optical computing and storage devices, visual displays, sound and video recording, and automotive safety technology? Let’s keep watching and see what springs from people’s needs and creativity.

Finally, just a quick mention of a recently published book that received many excellent reviews for a lively and engaging series of stories about the key developments of basic materials and materials science through history entitled Stuff Matters: Exploring the Marvelous Materials That Shape Our Man-Made World by Mark Midownik (Houghton Mifflin Harcourt, 2014).

[While I hope that this blog post will be enlightening, please be assured that no light waves were bent or harmed during the drafting process.]

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Another innovative project by Airbus to develop a drone for bringing Net access to remote and under-served regions was covered in the November 26, 2014 Subway Fold post entitled Robots and Diamonds and Drones, Aha! Innovations on the Horizon for 2015.