Metal-Filtering Sponge Removes Lead from Water                       

The researchers tested their new sponge on a highly contaminated sample of tap water.                                                 May 11, 2023

                                            Source: Caroline Harms/Northwestern University

Northwestern University engineers have developed a new sponge that can remove metals — including toxic heavy metals like lead and critical metals like cobalt — from contaminated water, leaving safe, drinkable water behind.

In proof-of-concept experiments, the researchers tested their new sponge on a highly contaminated sample of tap water, containing more than 1 part per million of lead. With one use, the sponge filtered lead to below detectable levels.

After using the sponge, researchers also were able to successfully recover metals and reuse the sponge for multiple cycles. The new sponge shows promise for future use as an inexpensive, easy-to-use tool in home water filters or large-scale environmental remediation efforts.

The study was published late yesterday (May 10) in the journal ACS ES&T Water. The paper outlines the new research and sets design rules for optimizing similar platforms for removing — and recovering — other heavy-metal toxins, including cadmium, arsenic, cobalt, and chromium.

“The presence of heavy metals in the water supply is an enormous public health challenge for the entire globe,” said Northwestern’s Vinayak Dravid, senior author of the study. “It is a gigaton problem that requires solutions that can be deployed easily, effectively, and inexpensively. That’s where our sponge comes in. It can remove the pollution and then be used again and again.”

Dravid is the Abraham Harris Professor of Materials Science and Engineering at Northwestern’s McCormick School of Engineering and director of global initiatives at the International Institute for Nanotechnology.

Sopping up spills

The project builds on Dravid’s previous work to develop highly porous sponges for various aspects of environmental remediation. In May 2020, his team unveiled a new sponge designed to clean up oil spills. The nanoparticle-coated sponge, which is now being commercialized by Northwestern spinoff MFNS Tech, offers a more efficient, economic, ecofriendly, and reusable alternative to current approaches to oil spills.

But Dravid knew it wasn’t enough. “When there is an oil spill, you can remove the oil,” he said. “But there also are toxic heavy metals — like mercury, cadmium, sulfur, and lead — in those spills. So, even when you remove the oil, some of the other toxins might remain.

Rinse and repeat

To tackle this aspect of the issue, Dravid’s team, again, turned to sponges coated with an ultrathin layer of nanoparticles. After testing many different types of nanoparticles, the team found that a manganese-doped goethite coating worked best. Not only are manganese-doped goethite nanoparticles inexpensive to make, easily available and nontoxic to humans, but they also have the properties necessary to selectively remediate heavy metals.

“You want a material with a high surface area, so there’s more room for the lead ions to stick to it,” said Benjamin Shindel, a Ph.D. student in Dravid’s lab and the paper’s first author. “These nanoparticles have high-surface areas and abundant reactive surface sites for adsorption and are stable, so they can be reused many times.”

The team synthesized slurries of manganese-doped goethite nanoparticles, as well as several other compositions of nanoparticles, and coated commercially available cellulose sponges with these slurries. Then, they rinsed the coated sponges with water in order to wash away any loose particles. The final coatings measured just tens of nanometers in thickness.

When submerged into contaminated water, the nanoparticle-coated sponge effectively sequested lead ions. The U.S. Food and Drug Administration requires that bottled drinking water is below 5 parts per billion of lead. In filtration trials, the sponge lowered the amount of lead to approximately 2 parts per billion, making it safe to drink.

“We’re really happy with that,” Shindel said. “Of course, this performance can vary based on several factors. For instance, if you have a large sponge in a tiny volume of water, it will perform better than a tiny sponge in a huge lake.”

Recovery bypasses mining

From there, the team rinsed the sponge with mildly acidified water, which Shindel likened to “having the same acidity of lemonade.” The acidic solution caused the sponge to release the lead ions and be ready for another use. Although the sponge’s performance declined after the first use, it still recovered more than 90% of the ions during subsequent use cycles.

This ability to gather and then recover heavy metals is particularly valuable for removing rare, critical metals, such as cobalt, from water sources. A common ingredient in lithium-ion batteries, cobalt is energetically expensive to mine and accompanied by a laundry list of environmental and human costs.

If researchers could develop a sponge that selectively removes rare metals, including cobalt, from water, then those metals could be recycled into products like batteries.

“For renewable energy technologies, like batteries and fuel cells, there is a need for metal recovery,” Dravid said. “Otherwise, there is not enough cobalt in the world for the growing number of batteries. We must find ways to recover metals from very diluted solutions. Otherwise, it becomes poisonous and toxic, just sitting there in the water. We might as well make something valuable with it.”

Standardized scale

As a part of the study, Dravid and his team set new design rules to help others develop tools to target particular metals, including cobalt. Specifically, they pinpointed which low-cost and nontoxic nanoparticles also have high-surface areas and affinities for sticking to metal ions. They studied the performance of coatings of manganese, iron, aluminum, and zinc oxides on lead adsorption. Then, they established relationships between the structures of these nanoparticles and their adsorptive properties.

Called Nanomaterial Sponge Coatings for Heavy Metals (or “Nano-SCHeMe”), the environmental remediation platform can help other researchers differentiate which nanomaterials are best suited for particular applications.

“I’ve read a lot of literature that compares different coatings and adsorbents,” said Caroline Harms, an undergraduate student in Dravid’s lab and paper co-author. “There really is a lack of standardization in the field. By analyzing different types of nanoparticles, we developed a comparative scale that actually works for all of them. It could have a lot of implications in moving the field forward.”

Dravid and his team imagine that their sponge could be used in commercial water filters, for environmental clean-up or as an added step in water reclamation and treatment facilities.

“This work may be pertinent to water quality issues both locally and globally,” Shindel said. “We want to see this out in the world, where it can make a real impact.”

TRIZ:  The use of Principles #24, Mediator and  #31, Porous Materials, to filter out harmful contaminants (heavy-metals) from polluted water. Ideal Final Results is to have a robust filtering system that removes harmful contaminants and remains in continuous use, Principle #20. Also, recapturing the harmful contaminants and recycling them will generate a cashflow is Principle #22 and keep the contaminants from being dumped into the environment.

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Unmanned Aerial Vehicle is Based on da Vinci Aerial Screw Design

Crimson Spin, a small, unmanned aerial vehicle (UAV) — flies through the combined lift of four, whirring red spiral-shaped blades. (Image: UMD Design Team)

In the fifteenth century, artist and engineer Leonardo da Vinci envisioned a craft that flew using a single helix-shaped propeller — the aerial screw — viewed by many as the first vertical take-off and landing (VTOL) machine ever designed.

In 2020, the Vertical Flight Society’s (VFS) 37th Annual Student Design Competition challenged students from across the world to reimagine da Vinci’s design. Using modern-day analytical and design tools, students were tasked to design and demonstrate a feasible modern-day VTOL vehicle based on the aerial screw concept and demonstrate the consistency of its physics.

Unveiled at the Vertical Flight Society’s 2022 Transformative Vertical Flight Conference — Crimson Spin, a small, unmanned aerial vehicle (UAV) — flies through the combined lift of four whirring red spiral-shaped blades.

The craft was the culmination of more than two years’ worth of work stemming from UMD’s 2020 winning graduate entry. The prize-winning design, named Elico, derived its name from the Italian root for the words “helicopter,” “propeller,” “helix,” and “screw,” all rooted in Leonardo’s drawing of the aerial screw.

The design did in fact look functional — on paper and in computer simulations — but could it actually fly in reality? “We saw some really interesting behaviors in the lift mechanisms of the air screw in our computational fluid dynamics simulations and models, where we found an edge vortex that would form,” explained team member Ilya Semenov. “But with such a novel design, we couldn’t be 100 percent sure that the phenomenon was true, so creating a working model would help us validate if it was in fact happening.”

Developed as a technology demonstrator, Crimson Spin was designed as a fully autonomous, manned quadrotor vehicle, and improves on da Vinci’s design by using a tapered aerial screw rotor to provide all lift, thrust, and control of the vehicle. A modular framework allows Crimson Spin to adapt to changing mission requirements and has hover and forward flight capabilities. According to the team, it allows riders to experience the genius of Leonardo da Vinci first-hand, safely and easily, by using an all-electric power plant, ultralight composite airframe, and pushbutton operation.

“That first successful flight was an incredible moment,” said team member Austin Prete. “It took three months, just trying to get it to fly correctly.”

While the research and findings are far too preliminary to extract potential applications at this point, making a working model based on the design has been a success in and of itself.

“Just the way the air screw worked was surprising,” added James Sutherland, Ph.D. candidate and team captain of the 2020 design team. “It’s possible that the aerial screw might be less noisy or create less downwash than a regular rotor with the same amount of thrust, but there is still a lot to learn and study before we know where it could be applied.”

Prete added that another interesting finding of the design was that the screws can create the same amount of lift but with fewer rotations compared to a traditional rotor, which may contribute to the reduced downwash — a not insignificant issue when flying traditional rotorcrafts.

Since the technology is so new, the team agrees that characterizing the rotors is important so future work can be done to evaluate the aerial screw against existing rotor styles. That will help them to understand in what flight regimes the screw design might perform best.

“For example, can you make an adjustable rotor screw?” said Prete. “You can make adjustments to a traditional rotor inflight, so what adjustments could you make to an aerial screw mid-flight to change its performance?”

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MRI FOR ALL

by ADRIAN CHO                                                              23 FEB 2023

Hyperfine’s Swoop, the first U.S. FDA–approved low-field brain scanner, can be

wheeled to a patient’s bedside. DEREK DUDEK/HYPERFINE

The patient, a man in his 70s with a shock of silver hair, lies in the neuro intensive care unit (neuro ICU) at Yale New Haven Hospital. Looking at him, you’d never know that a few days earlier a tumor was removed from his pituitary gland. The operation didn’t leave a mark because, as is standard, surgeons reached the tumor through his nose. He chats cheerfully with a pair of research associates who have come to check his progress with a new and potentially revolutionary device they are testing.

The cylindrical machine stands chest high and could be the brooding older brother of R2D2, the Star Wars robot. One of the researchers carefully guides the 630-kilogram self-propelled scanner up to the head of the bed, steering it with a joystick. Lifting the man by his bed sheet, the researchers help him ease his head into the Swoop—a portable magnetic resonance imaging (MRI) scanner made by a company called Hyperfine.

“Do you want ear plugs?” asks Vineetha Yadlapalli, the second researcher.

“Is it as loud as a regular MRI?”

“Not at all.”

“Then I guess I don’t need them.”

After propping up the patient’s legs to ease the strain on his back, Yadlapalli sets the machine to work, tapping in a few instructions from an iPad. The machine emits a low growl, then proceeds to beep and click. Within minutes, an image of the patient’s brain appears on Yadlapalli’s tablet.

For a half-hour, the man lies quietly, hands folded across his belly. He could be getting his hair set in an old-fashioned hair dryer. In a small way, he’s a pioneer helping take MRI where it’s never gone before.

In many cases, MRI sets the gold standard in medical imaging. The first useful MRI images emerged in the late 1970s. Within a decade, commercial scanners had spread through medicine, enabling physicians to image not just bone, but soft tissues. If doctors suspect you have had a stroke, developed a tumor, or torn cartilage in your knee, they’ll likely prescribe an MRI.

If you’re fortunate enough to be able to get one, that is. An MRI scanner employs a magnetic field to twirl atomic nuclei in living tissue—specifically the protons at the heart of hydrogen atoms—so that they emit radio waves. To generate the field, a standard scanner employs a large, powerful superconducting electromagnet that pushes a machine’s cost to $1.5 million or more, pricing MRI out of reach of 70% of the world’s population. Even in the United States, getting an MRI may require days of waiting and a midnight drive to some distant hospital. The patient must come to the scanner, not the other way around.

For years, some researchers have been striving to build scanners that use much smaller permanent magnets, made of the alloy often found in desk toys. They produce fields roughly 1/25th as strong as a standard MRI magnet, which once would have been far too weak to glean a usable image. But, thanks to better electronics, more efficient data collection, and new signal processing techniques, multiple groups have imaged the brain in such low fields—albeit with lower resolution than standard MRI. The result is scanners small enough to roll to a patient’s bed and possibly cheap enough to make MRI accessible across the globe.

The resolution of a brain scan from a low-field machine (first image) is coarser than conventional MRI (second image), but both images clearly reveal a hemorrhage. YALE SCHOOL OF MEDICINE

The machines mark a technological triumph. Kathryn Keenan, a biomedical engineer at the National Institute of Standards and Technology who is testing a Hyperfine scanner, says, “Everyone that comes through is super impressed that it even works.” Some say the scanners could also transform medical imaging. “We’re potentially opening up a whole new field,” says Kevin Sheth, a neurologist at the Yale School of Medicine who has worked extensively with the Swoop but has no financial interest in Hyperfine. “It’s not a question of ‘Is this going to happen?’ It’s going to be a thing.”

In August 2020, the Swoop became the first low-field scanner to win U.S. Food and Drug Administration (FDA) approval to image the brain, and physicians are putting it through clinical studies at Yale New Haven and elsewhere. Other devices are close behind. But Andrew McDowell, a physicist and founder of the consulting firm NeuvoMR, LLC, cautions it’s not clear there’s a market for a low-field scanner, with its lower resolution. “The real challenge is going to be convincing doctors to start using it,” he says. “That’s very difficult because for good reasons they’re very conservative.”

AN MRI SCANNER WORKS nothing like a camera; it is actually a radio that tunes in to protons in living tissue. Like a tiny compass needle, each proton is magnetic, and ordinarily the protons point randomly in all directions (see graphic, below). However, an external magnetic field can align them. At that point, a pulse of radio waves of the right frequency and duration can tip them by 90°. The aligned protons then twirl like gyroscopes, emitting a radio signal of their own, whose frequency increases with the field’s strength.

That fleeting monotone radio hum reveals little. To create an image, the scanner must distinguish among waves coming from different points in the body. To do this, it sculpts the magnetic field, which makes protons at different locations sing at different frequencies and states of synchrony. The scanner must also distinguish one type of tissue from another, which it does by exploiting the fact that the radio signals fade at different rates in different tissues.

One reason the signal dies out is that the protons knock one another out of alignment through their own magnetic fields. The rate at which this happens differs between, say, fatty brain matter and watery cerebrospinal fluid. To measure the rate, the scanner applies pairs of pulses. The first pulse creates a signal that fades as the orientations of twirling protons fan out. The second reverses much of that evolution, eliciting an echo of the signal. The proton-proton interactions mute that echo, however. So the scanner can measure their rate by tracking how the echo shrinks as the delay between the two pulses increases.

While applying pair after pair of pulses, the scanner must simultaneously sort the echoes coming from different points in the brain. To do that, it relies on magnetic field gradients applied at key moments. For example, a gradient applied during the echo from chin to crown makes protons in different sideways slices through the head radiate at different frequencies. A gradient applied between pulses and across the head will set protons in vertical slices ahead or behind in their twirling, a “phase” difference that makes echoes from some slices reinforce one another and others cancel. By varying the gradient, the scanner can deduce the strength of the echo from each slice.

Over many repetitions, the scanner gathers a plethora of echoes in which intensity varies with delay, frequency, and phase. A standard mathematical algorithm decodes them to produce a map of how the proton-proton interactions vary throughout the brain, forming one type of MRI image. Other pulse sequences probe other tissue-specific processes—such as how fast protons diffuse, which can track fluid flow.

All that pulsing explains why MRI scans take time and why an MRI machine chirps, clicks, and buzzes. Those sounds emerge as mechanical stresses rattle the current-carrying coils that create the magnetic gradients. A technician can tell what kind of a scan a machine is doing just from those sounds, Yadlapalli says.

A stronger field makes all this easier by polarizing the protons more thoroughly and creating a bigger signal. A standard scanner’s magnet produces a field of 1.5 tesla—30,000 times as strong as Earth’s field—and some reach 3 or 7 tesla. Even so, the protons pointing along a 1.5-tesla field outnumber those pointing the other way by just 0.001%. Reduce the field strength by a factor of 25 and the polarization falls with it. The signal-to-noise ratio plummets even more, by a factor of nearly 300.

In principle, a low-field scanner could coax a signal from the noise by taking data over a longer time period—just as radio astronomers sift a weak signal from noise by training their dishes on a star for hours or days. That tack won’t work with a human, who can hold still only so long. So, in developing low-field MRI, researchers had to find ways to extract data much faster.

One key element is better hardware, says Joshua Harper, a neural engineer at the German Paraguayan University. “We now have really fast, really cheap electronics,” he says. “That’s really why it works.” Even so, doing low-field MRI in a hospital room is tricky. Metal in other machines and even the walls can distort the field, and static from other devices can disrupt the radio signal. So, scanners employ countermeasures. For example, Hyperfine’ s Swoop uses antennas to measure radio noise and cancel it, similar to how noise-canceling headphones block sound.

The new scanners also turn an aspect of the lower field to their advantage to run faster. To manipulate the protons, a high-field scanner must use higher frequency, higher energy radio waves, so it can pulse only so fast before it begins to heat the patient. Free of that speed limit, a low-field scanner can pulse faster and use more efficient pulse sequences, says Matthew Rosen of Massachusetts General Hospital, a physicist who co-founded Hyperfine. “We can interrogate very, very rapidly, doing things that you could never do at high field.”

Even so, gathering data fast enough for standard image reconstruction remains a challenge. One solution is to employ novel signal processing techniques, including artificial intelligence. Hyperfine engineers use a set of training images to teach a program called a neural network to construct brain images from relatively sparse data, says Khan Siddiqui, Hyperfine’ s chief medical officer and chief strategy officer. “That’s where our secret sauce comes in.”

Compared with a standard scan, a low-field image looks blurrier. Still, physicists see its beauty. “It’s this incredible physics success story,” Rosen says. “It’s not just we pointy headed physicists [goofing] off and doing stuff that nobody cares about.” The technology vindicates those toiling in a forgotten corner of the field, McDowell says. “Who in their right mind would build a 65-millitesla machine when the glory is in building the 11-tesla one?”

HYPERFINE SAYS ITS SWOOP SCANNER is off to a pretty glorious start. It has sold more than 100 of the machines, mostly in the United States, at about $250,000 apiece. The goal is not to replace high-field scanners, but to expand how MRI is used, Siddiqui says. “Our portable scanner brings MRI closer to the patient, both in time and in distance.” Hyperfine envisions using it in the neuro ICU to quickly assess patients too ill or unstable to wheel to a conventional MRI or a CT machine, which produces a type of 3D x-ray.

A Swoop’s magnet consists of two disks and produces a field of 64 millitesla. A scan from it feels dramatically different from a standard scan. In a conventional scanner, an automated table glides you bodily into the cylindrical magnet. With the Swoop, an able patient can scooch into the magnet as if wriggling under a car’s bumper. A helmetlike head piece containing the antennas cradles your head so snugly it may touch your nose, yet your arms and legs are free. The machine’s chirping is soft, even soothing.

In late 2019 and early 2020, as the coronavirus pandemic took hold, Sheth and colleagues tested the Swoop’s promise by scanning 50 ICU patients, including 20 with COVID-19. Because many were on ventilators and sedated, “we had no idea what their neurological status was and no way to take a look by any available imaging modality,” Sheth recalls. “And this provided us a way to do that at the bedside.” The scans revealed brain trauma in 37 cases, including eight COVID-19 patients, the researchers reported in January 2021 in JAMA Neurology.

A low-field MRI scanner images a patient in their bed in the intensive care unit at Yale New Haven

Hospital. YALE SCHOOL OF MEDICINE

The cheaper, smaller machines might also allow patients to get more frequent follow-up scans. That’s a prospect that resonates with Ronald Walsworth, a physicist at the University of Maryland, College Park, and co-founder of Hyperfine. In 2007, his then–2-year-old son developed a noncancerous brain tumor. He was treated successfully, says Walsworth, who serves on Hyperfine’s advisory board. Still, he says, “There were signs that were not caught early and things that were not decided most efficiently because the MRIs only could happen once in a while.”

The Swoop’s advantages have won it fans. “Oh, my God, what a beautiful, beautiful piece of technology,” says Steven Schiff, a pediatric neurosurgeon at Yale University who has no financial interest in Hyperfine. Still, the Swoop can miss details a high-field scanner would catch because its resolution of 1.5 millimeters is half that of a standard scanner. For example, Sheth’s team used it to image the brains of 50 patients who had had an ischemic stroke, visible with standard MRI. The Swoop missed the five smallest, millimeter-size strokes, the researchers reported in April 2022 in Science Advances.

That finding shows physicians will have to exercise judgment in deciding when to use each type of scanner, Sheth says. “You shouldn’t be too worried, but you should understand the context in which you might miss something,” he says. Still, McDowell notes doctors may shy away from a low-field scanner if they think using it could leave them open to a malpractice suit.

IN MUCH OF THE WORLD, MRI is simply unavailable. A team in the Netherlands hopes its scanner will change that. Its magnet differs dramatically from the Swoop’s. It consists of 4098 cubes of neodymium iron boron—an alloy developed in the 1980s by carmakers—embedded in a hollow plastic cylinder, and arranged in a configuration called a Halbach array to produce a uniform horizontal field. “Our system is intrinsically better and has fewer distortions,” asserts Andrew Webb, an MRI physicist at Leiden University Medical Centre, so it requires less help from processing such as machine learning.

A private company, Multiwave Technologies in Switzerland, is trying to bring the scanner to market. It will apply for FDA approval this year and aims to rent its machines in a subscription model, says Tryfon Antonakakis, Multiwave’s co-CEO. “Our goal is to make it as affordable as possible and not necessarily to be in the hospital,” says Antonakakis, an engineer and applied mathematician. “We are looking to go into the mountains, into the medical deserts in developing countries.”

Webb and his colleagues, including Martin van Gijzen, an applied mathematician at the Delft University of Technology, have another plan for spreading their technology: giving it away. “We made the decision—Martin, myself, all our team—that we were not going to patent things,” Webb says. “Everything is going to be open source,” so that anyone can download their design from the internet and build scanners. Webb and colleagues hope entrepreneurs in developing nations will manufacture them locally.

To seed the idea, they shipped a scanner, packaged as a kit, to Johnes Obungoloch, a biomedical engineer at Mbarara University of Science and Technology in Uganda, who was a graduate student at Pennsylvania State University, University Park, when Webb and Schiff were also there. In September 2022, Webb and others flew to Uganda to help Obungoloch and his team assemble the scanner in 11 days.

 Soon it will be put to use in a project to test the utility of low-field MRI in the developing world. The CURE Children’s Hospital of Uganda, a 55-bed pediatric neurosurgical facility in Mbale run by an international nonprofit, plans to compare Obugoloch’s scanner, a Swoop, and a CT scanner. Doctors will image children with hydrocephalus, in which cerebrospinal fluid collects in the brain and compresses it, potentially causing debilitating or fatal damage. Globally, hydrocephalus afflicts 400,000 children every year, and it accounts for 75% of the CURE hospital’s patients. In Africa, an infection is the usual cause..For years, Schiff and colleagues at the hospital have used CT scans to guide an innovative surgery that allows the fluid to drain into the brain’s ventricles—an alternative to installing a shunt to the abdomen. However, a CT scan exposes children to considerable x-ray radiation, so CURE doctors will see whether low-field MRI images can guide surgeons. “If the MRI proves comparable to the CT scan, then there is no reason why we should be using the CT scan anymore,” says Ronald Mulondo, a physician at CURE who directs the project.

The study is awaiting final governmental approval. If it’s successful, Obungoloch envisions building more scanners, perhaps for Africa’s six other CURE hospitals, and even sourcing some of the parts locally. Uganda has public health care, so that vision depends on government funding, he says.

Still, like their peers elsewhere, doctors in Uganda may have reservations about the technique’s limited resolution, Obungoloch notes. “The radiologists see it and say, ‘Well, this is a crappy image, and we don’t care how long it took you to acquire it.’” Government officials may also think Ugandans shouldn’t have to settle for lower resolution imaging, no matter how useful, he says.

In truth, developers of low-field MRI are pushing for nothing less than a rethink of medical imaging. “Is the best technology the scanner that can provide the highest quality images or is it the scanner that can lead to the most improved patient outcomes?” asks Harper, who collaborated on Webb’s open-source rig and hopes to acquire a Swoop.

What will win over doctors, Sheth says, will be a “use case”—a killer app for the scanners. For example, they might be put into special ambulances for stroke care. He questions whether Hyperfine and others have found that use case but predicts it will come.

file:///C:/Users/Owner/AppData/Local/Temp/msohtmlclip1/01/clip_image017.jpg" alt="Adrian Cho" width="86" height="120" />Then there are patients to win over. After his time in the Hyperfine scanner, the pituitary tumor patient confides to Yadlapalli that it wasn’t quite as comfortable as a regular MRI. Noting that he still can’t breathe through his nose because of the surgery, he says the snug-fitting head basket bothered him. “I’d rather be scooted over to a real MRI.” Call him a reluctant pioneer.

ABOUT THE AUTHOR

Adrian Cho, Author,  Staff Writer

TRIZ Notes: This new MRI system has been reduced in size, weight, do it in reverse and convenient to use. The system is more IDEAL and will continue to evolve closer to the IFR.  Just needs a few more “S” curves.

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Innovation for Urgency:

Understanding the Different Types of Innovations

by admin | Mar 10, 2023 |Innovation

IntroductionInnovation is a key driver of progress and success in any industry. However, not all innovations are created equal. Innovation can be classified in terms of impact or urgency. Impact-driven innovation is motivated by the desire to make more financial profits; impact is not necessarily seen as an impact for a better world. Urgency-driven innovation is driven by the need to address a problem that has pressing aspects on human quality of life; here impact is seen from the perspective of quality of life in general, including the positive impact on flora and fauna. Both types of innovation are essential for different industries and situations. Some innovations focus on addressing progress and superior performance, while others are designed to stop or control negative effects. Additionally, some innovations go beyond control and aim to eliminate problems altogether. In this post, we will explore the different types of innovations and their impact on industries.

Classification based on urgency for quality of lifeClassification based on urgency for quality of life

One type of innovation is the “vitamin” type. This innovation focuses on addressing progress and superior performance. It involves creating products or services that improve an existing process or provide a better experience for the user. This type of innovation is essential for industries that want to stay competitive and continue to grow. Examples of vitamin-type innovations include smartphones, high-performance vehicles, and advanced medical equipment.Some more examples in this category are:

• The introduction of smartphones with new features, such as higher resolution cameras and more powerful processors, improves the performance of previous models.

• The introduction of smartphones with new features, such as higher resolution cameras and more powerful processors, improves the performance of previous models.

• The development of new materials, such as graphene, that offer improved mechanical and electrical properties compared to traditional materials.

• The creation of more efficient solar cells that generate more electricity per unit area.

• Apple’s Air Pods Pro with noise-canceling technology enhances the user experience.

• Tesla’s electric cars offer superior performance compared to traditional combustion engine cars (YES! It is only a vitamin-type innovation. Why? Please, have a look here)

• Google’s search algorithm updates improve the accuracy and relevance of search results.

Another type of innovation is the “analgesic” type. This innovation focuses on stopping or keeping some negative effects under control. It involves creating products or services that address a problem or limitation of an existing product. This type of innovation is crucial for industries that want to prevent negative effects from impacting their business. Examples of analgesic-type innovations include cybersecurity software, pollution control systems, and safety equipment.

Examples in this category are also the followings:

• The development of vaccines and treatments for diseases, such as the COVID-19 vaccines, that help to mitigate the negative effects of the illness.

• The introduction of filters in cigarettes to reduce the amount of harmful chemicals that are released when smoking.

• The use of pollution control devices in factories to reduce the amount of harmful emissions released into the environment.

• Robots that collect waste from lakes and rivers to reduce the amount of harmful effects on environment.

• Robots that collect waste from lakes and rivers to reduce the amount of harmful effects on environment.

• Lifting car-parking that can park 20 cars on the surface covered by 3 cars.

• Water filters that remove harmful contaminants from drinking water, keeping people healthy and safe.

• Noise-cancelling headphones that reduce stress and fatigue caused by loud noises.

• Apps that limit screen time to help prevent digital addiction and associated negative effects.

The “antibiotic” type of innovation takes things to the next level. This type of innovation aims to eliminate problems or negative effects altogether. It involves creating products or services that fundamentally change the way things are done, often creating entirely new industries. This type of innovation is essential for industries that want to stay ahead of the curve and address major problems in a game-changing way. Examples of antibiotic-type innovations include renewable energy sources, autonomous vehicles, and artificial intelligence.The “antibiotic” type of innovation takes things to the next level. This type of innovation aims to eliminate problems or negative effects altogether. It involves creating products or services that fundamentally change the way things are done, often creating entirely new industries. This type of innovation is essential for industries that want to stay ahead of the curve and address major problems in a game-changing way. Examples of antibiotic-type innovations include renewable energy sources, autonomous vehicles, and artificial intelligence.Examples we can add here are also:

• The development of antibiotics to treat bacterial infections, which have helped to reduce mortality rates from infectious diseases.

• The introduction of water treatment technologies, such as chlorination and filtration, that have helped to eliminate waterborne diseases in developed countries.

• The creation of renewable energy sources, such as wind and solar power, that help to eliminate reliance on fossil fuels and reduce carbon emissions.

• Recycling technology that can convert waste materials into usable products is an “antibiotic” type innovation in the waste management industry. It aims to eliminate the negative effects of waste, including environmental pollution and resource depletion.

• Tesla Powerwall – addresses the elimination of energy problems by providing an efficient and sustainable energy storage solution for households and businesses.

• Zero Waste manufacturing – addresses the elimination of waste problems by designing manufacturing processes that eliminate waste, increase efficiency, and reduce environmental impact.

• Automated Inventory Management Systems – addresses the elimination of inventory problems by using sensors, machine learning, and analytics to optimize inventory levels, reduce waste, and improve supply chain efficiency.

• Carbon Capture Technology – addresses the elimination of carbon emissions by capturing and storing carbon dioxide emissions from industrial processes before they are released into the atmosphere.

All three categories of innovations have the potential to be of interest to investors, depending on the specific context and industry.All three categories of innovations have the potential to be of interest to investors, depending on the specific context and industry.

Vitamin-type innovations, which focus on progress and superior performance, may be particularly appealing to investors looking for growth opportunities and high returns on investment.

Analgesic-type innovations, which address negative effects or problems that already exist, may also be attractive to investors if they offer cost savings or other benefits to customers.

Antibiotic-type innovations, which aim to eliminate problems or negative effects, may be less immediately attractive to investors because they often require significant investment and may take longer to generate returns. However, these types of innovations may be more valuable in the long term as they can create new markets or disrupt existing ones and may also have more significant social and environmental impacts.

Conclusions

Understanding the different types of innovations and their potential impact can help individuals and organizations prioritize their efforts and investments. While all types of innovations have value, it is important to recognize that analgesic and antibiotic innovations have a significant impact on society and can offer attractive investment opportunities. These types of innovations may not receive the same level of attention as vitamin-type innovations because of much higher research and development risks, but they can provide more stable and predictable returns on investment over the long term. Usually in hackathons we see vitamin-type innovations, which are not necessarily the stringent ones for humankind. We must address this issue and find new models to support ideation and development around analgesic and antibiotic-types of innovations. It is worth considering how these different types of innovations are addressed in different industries and sectors. Furthermore, it is important to consider the potential trade-offs and unintended consequences of each type of innovation. For example, an impact-driven innovation may generate significant financial returns, but it may also have negative societal or environmental impacts. Similarly, an analgesic-type innovation or even an antibiotic-type innovation may solve a particular problem, but it may also create new problems or unintended consequences. So, we have to analyze any type of innovation in a holistic way and from multiple angles, over their life-cycles, over the supply and value chains, etc.Innovation is a complex and multifaceted process, and there is no one-size-fits-all approach to addressing the challenges and opportunities that it presents. By understanding the different types of innovations and their potential impact, individuals and organizations can make more informed decisions about where to focus their efforts and investments, and how to balance short-term and long-term goals.

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Credits: Stelian Brad

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PRODUCT DEVELOPMENT

Keeping Drivers Safe with a Road That Can Melt Snow, Ice on Its Own

The researchers prepared a sodium acetate salt and combined it with a surfactant, silicon dioxide, sodium bicarbonate and blast furnace slag.

American Chemical Society                                                                                  Feb 17, 2023

Adapted from ACS Omega 2023, DOI: 10.1021/acsomega.2c07212

Slipping and sliding on snowy or icy roads is dangerous. Salt and sand help melt ice or provide traction, but excessive use is bad for the environment. And sometimes, a surprise storm can blow through before these materials can be applied. Now, researchers reporting in ACS Omega have filled microcapsules with a chloride-free salt mixture that’s added into asphalt before roads are paved, providing long-term snow melting capabilities in a real-world test. 

Driving on snowy roads at or near-freezing temperatures can create unsafe conditions, forming nearly invisible, slick black ice, if roads aren’t cleaned quickly enough. But the most common ways to keep roads clear have significant downsides:

• Regular plowing requires costly equipment, is labor intensive and can damage pavement. 
• Heavy salt or sand applications can harm the environment.
• Heated pavement technologies are prohibitively expensive to use on long roadways.

Recently, researchers have incorporated salt-storage systems into “anti-icing asphalt” to remove snow and prevent black ice from forming. However, these asphalt pavements use corrosive chloride-based salts and only release snow-melting substances for a few years. So, Yarong Peng, Quansheng Zhao, Xiaomeng Chu and colleagues wanted to develop a longer-term, chloride-free additive to effectively melt and remove snow cover on winter roads. 

The researchers prepared a sodium acetate salt and combined it with a surfactant, silicon dioxide, sodium bicarbonate and blast furnace slag — a waste product from power plant operations — to produce a fine powder. They then coated the particles in the powder with a polymer solution, forming tiny microcapsules. Next, the team replaced some of the mineral filler in an asphalt mixture with the microcapsules.

In initial experiments, a pavement block made with the new additive lowered the freezing point of water to -6 F. And the researchers estimated that a 5-cm-thick layer of the anti-icing asphalt would be effective at melting snow for seven to eight years. A real-world pilot test of the anti-icing asphalt on the off-ramp of a highway showed that it melted snow that fell on the road, whereas traditional pavement required additional removal operations. Because the additive used waste products and could release salt for most of a road’s lifetime, the researchers say that is a practical and economic solution for wintertime snow and ice removal.

TRIZ: Slippery, icy roads are dangerous to drive on. The Ideal Final Result concept tells us that the system should fix itself using resources that are readily available and free/low cost. The main component of the road system is the road, more accurately, the black top. The road surface should be able to melt/remove snow and ice. By merging (Prin #5) a low cost additive to the black top, we should be able to provide an environment where the road itself will melt the snow and ice.

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Engineers Grow “perfect” atom-thin Materials on

Industrial Silicon Wafers  

Their technique could allow chip manufacturers to produce next-generation transistors based on materials other than silicon.

MIT engineers grow “perfect” atom-thin materials on industrial silicon wafers. Their technique could allow chip manufacturers to produce next-generation transistors based on materials other than silicon.

Jennifer Chu | MIT News Office                       Publication Date:       January 18, 2023

Caption: By depositing atoms on a wafer coated in a “mask” (top left), MIT engineers can corral the atoms in the mask’s individual pockets (center middle), and encourage the atoms to grow into perfect, 2D, single-crystalline layers (bottom right).

Credits:  Courtesy of the researchers. Edited by MIT News.

Engineers grow defect-free, atomically thin films on top of silicon wafers; new method may allow computer chipmakers to produce 2D transistors for electronics.

True to Moore’s Law, the number of transistors on a microchip has doubled every year since the 1960s. But this trajectory is predicted to soon plateau because silicon — the backbone of modern transistors — loses its electrical properties once devices made from this material dip below a certain size.

Enter 2D materials — delicate, two-dimensional sheets of perfect crystals that are as thin as a single atom. At the scale of nanometers, 2D materials can conduct electrons far more efficiently than silicon. The search for next-generation transistor materials therefore has focused on 2D materials as potential successors to silicon.

But before the electronics industry can transition to 2D materials, scientists have to first find a way to engineer the materials on industry-standard silicon wafers while preserving their perfect crystalline form. And MIT engineers may now have a solution.

The team has developed a method that could enable chip manufacturers to fabricate ever-smaller transistors from 2D materials by growing them on existing wafers of silicon and other materials. The new method is a form of “nonepitaxial, single-crystalline growth,” which the team used for the first time to grow pure, defect-free 2D materials onto industrial silicon wafers.

With their method, the team fabricated a simple functional transistor from a type of 2D materials called transition-metal dichalcogenides, or TMDs, which are known to conduct electricity better than silicon at nanometer scales.

“We expect our technology could enable the development of 2D semiconductor-based, high-performance, next-generation electronic devices,” says Jeehwan Kim, associate professor of mechanical engineering at MIT. “We’ve unlocked a way to catch up to Moore’s Law using 2D materials.”

Kim and his colleagues detail their method in a paper appearing today in Nature. The study’s MIT co-authors include Ki Seok Kim, Doyoon Lee, Celesta Chang, Seunghwan Seo, Hyunseok Kim, Jiho Shin, Sangho Lee, Jun Min Suh, and Bo-In Park, along with collaborators at the University of Texas at Dallas, the University of California at Riverside, Washington University in Saint Louis, and institutions across South Korea.

A crystal patchwork

To produce a 2D material, researchers have typically employed a manual process by which an atom-thin flake is carefully exfoliated from a bulk material, like peeling away the layers of an onion.

But most bulk materials are polycrystalline, containing multiple crystals that grow in random orientations. Where one crystal meets another, the “grain boundary” acts as an electric barrier. Any electrons flowing through one crystal suddenly stop when met with a crystal of a different orientation, damping a material’s conductivity. Even after exfoliating a 2D flake, researchers must then search the flake for “single-crystalline” regions — a tedious and time-intensive process that is difficult to apply at industrial scales.

Recently, researchers have found other ways to fabricate 2D materials, by growing them on wafers of sapphire — a material with a hexagonal pattern of atoms which encourages 2D materials to assemble in the same, single-crystalline orientation.

“But nobody uses sapphire in the memory or logic industry,” Kim says. “All the infrastructure is based on silicon. For semiconductor processing, you need to use silicon wafers.”

However, wafers of silicon lack sapphire’s hexagonal supporting scaffold. When researchers attempt to grow 2D materials on silicon, the result is a random patchwork of crystals that merge haphazardly, forming numerous grain boundaries that stymie conductivity. “It’s considered almost impossible to grow single-crystalline 2D materials on silicon,” Kim says. “Now we show you can. And our trick is to prevent the formation of grain boundaries.”

Seed pockets

The team’s new “nonepitaxial, single-crystalline growth” does not require peeling and searching flakes of 2D material. Instead, the researchers use conventional vapor deposition methods to pump atoms across a silicon wafer. The atoms eventually settle on the wafer and nucleate, growing into two-dimensional crystal orientations. If left alone each “nucleus,” or seed of a crystal, would grow in random orientations across the silicon wafer. But Kim and his colleagues found a way to align each growing crystal to create single-crystalline regions across the entire wafer.

To do so, they first covered a silicon wafer in a “mask” — a coating of silicon dioxide that they patterned into tiny pockets, each designed to trap a crystal seed. Across the masked wafer, they then flowed a gas of atoms that settled into each pocket to form a 2D material — in this case, a TMD. The mask’s pockets corralled the atoms and encouraged them to assemble on the silicon wafer in the same, single-crystalline orientation.

“That is a very shocking result,” Kim says, “You have single-crystalline growth everywhere, even if there is no epitaxial relation between the 2D material and silicon wafer.” With their masking method, the team fabricated a simple TMD transistor and showed that its electrical performance was just as good as a pure flake of the same material.

They also applied the method to engineer a multilayered device. After covering a silicon wafer with a patterned mask, they grew one type of 2D material to fill half of each square, then grew a second type of 2D material over the first layer to fill the rest of the squares. The result was an ultrathin, single-crystalline bilayer structure within each square. Kim says that going forward, multiple 2D materials could be grown and stacked together in this way to make ultrathin, flexible, and multifunctional films.

“Until now, there has been no way of making 2D materials in single-crystalline form on silicon wafers, thus the whole community has been struggling to realize next-generation processors without transferring 2D materials,” Kim says. “Now we have completely solved this problem, with a way to make devices smaller than a few nanometers. This will change the paradigm of Moore’s Law.”

This research was supported in part by the U.S. Defense Advanced Research Projects Agency, Intel, the IARPA MicroE4AI program, MicroLink Devices, Inc., ROHM Co., and Samsung.

TRIZ Applications: Follow Lines of Evolution, system should get larger or smaller. Principles of using a mediator and thin films. What other TRIZ tools do you find in the paper?

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Exploring the Effectiveness of Inventive Principles of TRIZ on Developing researchers’ innovative capabilities: a case study in an innovative Research Center 

 Mostafa Jafari, Peyman Akhavan, Hamaid R. Zarghami, and Naser Asgari

Department of Industrial Engineering, Iran University of Science and Technology, Tehran, Iran

Abstract

Purpose – The purpose of this paper is to explore the efficacy of 40 inventive principles of TRIZ for developing researchers’ innovative capabilities and to evaluate the extent of application of “40 inventive principles” by inventors In Research Center of Intelligent and Signal Processing (A Successful research center that is producing new products in the field of signal processing and medical engineering).

Design/methodology/approach

 – A range of relevant literature is explored initially. A questionnaire about 40 inventive principles of TRIZ was developed based on literature review.  

Finally, a data analysis including descriptive statistics, correlation and regression analysis was designed by using SPSS software.

Findings – 

The results showed that about 71% of the researchers have employed TRIZ above the average in their innovative products. Also these studied researchers used TRIZ principles unintentionally. Therefore, if this research center and similar institutes want to make full use of their Researchers’ abilities, they can facilitate innovation through offering courses on TRIZ, the principles of TRIZ and its other tools to them.

 Research limitations/implications

 – This research explore the using of 40 inventive principles as TRIZ simplest tools in an innovative research center without information of TRIZ field. It may need further research to be exploring through other tools of TRIZ and repeat this work in organizations using TRIZ with information from it. Although all of selected researchers were inventor and elite in their fields but a limitation of this research is exploring one successful research center and it can be done in a spread area in all of industries for generalized results. It is needed to note this research is a start for evaluate of using from TRIZ principles and continuing this work was needed through other researchers in all of field and organizations in all of countries.

Originality/value

 – This study is probably the first to provide an exploring of TRIZ inventive principles applications through a research center. Using finding of this research, this research center and other similar research organizations interested in implementing innovative problem-solving techniques will be more familiar with some benefits of TRIZ implementation in innovative accelerate for innovative problem solving in today’s complex competitive environment.

This research is somewhat different from previous works and the way of doing this research is unique in the world.

We explore efficacy of TRIZ inventive principles on researchers’ innovative capabilities through unintentional and intentional using from TRIZ principles by researchers of a successful inventor research center which have powerful researchers at field of signal processing. It is needed to note this research is a start for evaluate of using from TRIZ principles and continuing this work was needed through other researchers in all of field and organizations.

Keywords: Systematic innovation, TRIZ, 40 inventive principles, Researchers’ innovative capabilities, NPD.

The present research has been conducted in order to assess the usage and efficacy of the 40 inventive principles of TRIZ for developing researchers’ innovative capabilities. In other words, it was done to find out whether the principles formulated by Altshuller through an analysis of inventions in the past, are used by contemporary inventor researchers who are not familiar with TRIZ in our case, and whether explaining these principles can result in enhancing the ability of researchers to use existing knowledge more efficiently. In fact, contemporary researchers and those who lived before Altshuller have this in common, that they all had no understanding of TRIZ. We have made an effort to show how much the researchers in the Research Center of Intelligent Signal Processing, as a successful producer of inventive products, use the principles of TRIZ? The results showed that about 71% of the researchers have employed TRIZ above the average and the main hypothesis (H1) of the research was confirmed with confidence level of 95%. It means most researchers used TRIZ principles more than the average number. A considerable finding was that all 41 people who were selected from a population of 50 researchers said they didn’t know anything about TRIZ. It means the researchers used TRIZ principles unintentionally. Considering that the research center is an organization with lots of laboratories along with hardware and software facilities that help develop medical equipment and produce software for processing life indicators, probably the results achieved from this research center could be generalized to a wider population and to similar institutes. We could conclude that if this research center and similar institutes want to make full use of their researchers’ abilities, they should facilitate innovation through offering courses on systematic innovation, such as the principles of TRIZ to their employees; thanks to the researchers conducted by Altshuller, his students, and other scholars, TRIZ has already provided us with required tools. Exploring all innovative aspects of TRIZ needs a period of time as long as its existence. In addition, a trial-and-error approach to innovation is neither scientifically nor economically in the 3rd millennium. So, we can conclude that TRIZ could be applied for improving researchers’ capabilities. So, it would be good ideas to introduce TRIZ to knowledge-workers and researchers in research organizations in order to use its potential for developing their innovative practices. This research also shows that the priority given to each principle varies among researchers (see, table 5). This result supported previous findings in ranking principles about different ranking of principle in different fields (Mann, 2004a; Mann, 2004b). It was revealed that there is a positive and significant correlation between “using TRIZ principles” and “making use of previously invented methods to develop new products”. Considering that the philosophy of TRIZ is to summarize the knowledge of innovation so that inventors in any field of science would take advantage of it, the correlation between using previously invented methods and using TRIZ principles shows that TRIZ has done its best to summarize and simplify innovative principles. Regression analysis in table 7 shows, 60 percent of changing of “extent of unintentional usage of TRIZ principles by researchers” is predicted by” the extent of utilization of results of previously innovative products”. It also shows more extent of utilization of results of previously innovative products by researchers leads to higher unintentionally using from TRIZ inventive principles. So, Altshuller studied the previous patents completely and represents an excellent category of innovative principles (TRIZ). As it wasn’t observed any relationship between trial-and-error approach, the number of accomplished inventive projects, age and another demographic features and using TRIZ principles, we can conclude that these factors don’t affect the result of using TRIZ principles. Besides, more experience and other surveyed factors can’t lead to higher unintentionally using from TRIZ inventive principles, so we strongly suggest that innovators need to have access to these tools to increase their innovative capabilities through TRIZ intentionally with applicable learning of 40 inventive principles and other TRIZ tools. Perhaps evaluation of the usage of TRIZ, especially in terms of intentional or unintentional usage is carried out in the present research for the first time. It seems no similar research has ever been conducted in such organized and scientific fashion that is done in this research in the studied field.

Suggestions for Further Research

Considering that this research is the first scientific survey conducted on the use of TRIZ (basis not availability books and papers about it), it is necessary to evaluate the use of TRIZ principles in other innovative organizations to find out the efficacy of TRIZ in a more comprehensive way. In addition, other researchers might work on the practical methods of encouraging innovators to use TRIZ; they might work on training innovators to use correct and effective techniques of TRIZ as well. And researchers from other countries can make use of the same procedure to evaluate intentional and unintentional uses of TRIZ principles in creative institutes of their countries. For generalizing these results, a number of spread surveys at many innovative research organizations are need with the way of present research.

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Trashfence Catches a Garbage Tsunami Heading Downriver    

Ben Munson, Unit,   202 Productions   Eric Sorensen                         Jul 28, 2022

Trash is everywhere. It’s on land, where it sometimes piles so high it becomes a smoldering mountain. It’s in space, where it breaks down differently while moving at blistering speeds and battered. And it’s in our water, which sometimes forms huge garbage waves.

The Ocean Cleanup, a nonprofit environmental engineering organization, has identified one river where the trash waves seem to be continually breaking. The group said the Rio Motagua basin in Guatemala is particularly messy, sending an estimated 20,000 tons of plastic into the Caribbean Sea annually. That means this one river is responsible for 2% of the plastic that enters the oceans worldwide.

To push back against the rush of rubbish, Ocean Cleanup has developed the eight-meter-tall Interceptor Trashfence. It looks like a significant metal volleyball net, and it’s designed to contain trash upstream before it can hit the ocean and disperse. It’s an upgraded version of the Interceptor Original, whose 10,000-kilogram capacity wouldn’t hold up long against the annual Motagua floods.

The Interceptor Trashfence uses technology standards in avalanche and landslide protection systems. With the reinforced model on the riverbed, the idea is to catch the trash and then wait for water levels to recede before moving the garbage pile with excavators.

In a video showing the Interceptor Trashfence in action earlier this year, a shocking amount of garbage rages down the Rio Motagua before the fence traps it. Unfortunately, the Trashfence eventually springs a leak because the river’s force erodes the river base below the fence. Fortunately, Ocean Cleanup engineers don’t seem discouraged.

For now, the organization is optimizing the design and figuring out just how many Trashfences it will take to keep all or most of the plastic from making it to the sea.

TRIZ Application: To clean up the ever-growing problem of plastic trash pollution in our oceans, the first step is that we need to stop the influx of plastic trash. Using TRIZ Principle # 10 Prior Action, we can perform this task by blocking the trash on rivers with an "Interceptor Trashfence." It is easier to recover this trash before it is dispersed into the ocean.

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July 21, 2022

With bans as early as 2025, BASF and MIT are searching for a biodegradable substitute.

MIT News

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Microplastics, tiny particles of plastic now found worldwide in the air, water, and soil, are increasingly recognized as a severe pollution threat and are now found in the bloodstreams of animals and people. Some microplastics are intentionally added to various products, including agricultural chemicals, paints, cosmetics, and detergents. According to the European Chemicals Agency, this substance amounts to an estimated 50,000 tons annually in the European Union alone. The EU has already declared that these added, nonbiodegradable microplastics must be eliminated by 2025. So the search is on for suitable replacements, which do not currently exist.

Now, a chemical company BASF and the Massachusetts Institute of Technology scientists have developed a silk-based system that could provide an inexpensive and easily manufactured substitute. The new process is described in a paper in the journal Small.

The microplastics widely used in industrial products generally protect some specific active ingredient (or ingredients) from being degraded by exposure to air or moisture until they are needed. They provide a slow release of the active ingredient for a targeted period and minimize adverse effects to its surroundings. For example, vitamins are often delivered as microcapsules packed into a pill or capsule, and pesticides and herbicides are similarly enveloped. But the materials used today for such microencapsulation are plastics that persist in the environment for a long time. Until now, no practical, economical substitute has been available to biodegrade naturally.

Much of the burden of environmental microplastics comes from other sources, such as the degradation over time of larger plastic objects such as bottles and packaging and the wear of car tires. Each of these sources may require its kind of solutions for reducing its spread, says Bernedetto Marelli, a co-author of the study and an MIT professor of civil and environmental engineering. The European Chemical Agency has estimated that the intentionally added microplastics represent approximately 10-15% of the total amount in the environment. Still, this source may be relatively easy to address using this nature-based biodegradable replacement.

"We cannot solve the whole microplastics problem with one solution that fits them all," Marelli says. "Ten percent of a big number is still a big number, and we'll solve climate change and pollution of the world one percent at a time."

Unlike the high-quality silk threads used for delicate fabrics, the silk protein used in the new alternative material is widely available and less expensive, Liu says. While silkworm cocoons must be painstakingly unwound to produce the fine threads needed for fabric, for this use, non-textile-quality cocoons can be used, and the silk fibers can be dissolved using a scalable water-based process. The processing is so simple and tunable that the resulting material can be adapted to work on existing manufacturing equipment, potentially providing a simple "drop-in" solution using existing factories.

Silk is considered safe for food or medical use, as it is non-toxic and degrades naturally in the body. In lab tests, the researchers demonstrated that the silk-based coating material could be used in existing, standard spray-based manufacturing equipment to make a water-soluble micro-capsule herbicide product. This method was then tested in a greenhouse on a corn crop. The test showed it worked even better than an existing commercial product, inflicting less damage to the plants, says Muchun Liu, an MIT postdoc who is the study's lead author.

While other groups have proposed biodegradable materials that may work at a small laboratory scale, Marelli says, there is a "strong need" for such a material to work well commercially without sacrificing performance.  

Liu explains that the secret to making the material compatible with existing equipment is in the silk material's tunability. By precisely adjusting the polymer chain arrangements of silk materials and the addition of a surfactant, it is possible to fine-tune the properties of the resulting coatings once they dry out and harden. The material can be hydrophobic (water-repelling) even though it is made and processed in a water solution. Or it can be hydrophilic (water-attracting) or anywhere in between, and for a given application, it can be made to match the characteristics of the material it is being used to replace.

The new method can use low-grade silk that is unusable for fabrics and large quantities of which are currently discarded because they have no significant uses, Liu says. It can also use discarded silk fabric, diverting that material from being disposed of in landfills.

Currently, 90% of the world's silk production takes place in China, Marelli says, but that's mainly because China has perfected the production of the high-quality silk threads needed for fabrics. But because this process uses bulk silk and does not need that quality, production could quickly be ramped up in other parts of the world to meet local demand if this process becomes widely used.

This process "represents a potentially highly significant advance in active ingredient delivery for a range of industries, particularly agriculture," says Jason White, director of the Connecticut Agricultural Experiment Station. He was not associated with the research. "Given the current and future challenges related to food insecurity, agricultural production, and a changing climate, novel strategies such as this are greatly needed."

The research team also included Pierre-Eric Millard, Ophelie Zeyons, Henning Urch, Douglas Findley, and Rupert Konradi from the BASF corporation in Germany. The U.S. BASF supported the work through the Northeast Research Alliance (NORA).

This article was originally published in MIT News. 

TRIZ thoughts: Ideality – Low-grade silk cocoons are cheap, readily available, and a biodegradable resource that can replace non- biodegradable microplastics.

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