Tag Archives: Finland

Carbon nanotubes (CNTs) in 466 colours

Caption: A color map illustrates the inherent colors of 466 types of carbon nanotubes with unique (n,m) designations based their chiral angle and diameter. Credit: Image courtesy of Kauppinen Group/Aalto University

This is, so to speak, a new angle on carbon nanotubes (CNTs). It’s also the first time I’ve seen two universities place identical news releases on EurekAlert under their individual names.

From the Dec. 14, 2020 Rice University (US) news release or the Dec. 14, 2020 Aalto University (Finland) press release on EurekAlert,

Nanomaterials researchers in Finland, the United States and China have created a color atlas for 466 unique varieties of single-walled carbon nanotubes.

The nanotube color atlas is detailed in a study in Advanced Materials about a new method to predict the specific colors of thin films made by combining any of the 466 varieties. The research was conducted by researchers from Aalto University in Finland, Rice University and Peking University in China.

“Carbon, which we see as black, can appear transparent or take on any color of the rainbow,” said Aalto physicist Esko Kauppinen, the corresponding author of the study. “The sheet appears black if light is completely absorbed by carbon nanotubes in the sheet. If less than about half of the light is absorbed in the nanotubes, the sheet looks transparent. When the atomic structure of the nanotubes causes only certain colors of light, or wavelengths, to be absorbed, the wavelengths that are not absorbed are reflected as visible colors.”

Carbon nanotubes are long, hollow carbon molecules, similar in shape to a garden hose but with sides just one atom thick and diameters about 50,000 times smaller than a human hair. The outer walls of nanotubes are made of rolled graphene. And the wrapping angle of the graphene can vary, much like the angle of a roll of holiday gift wrap paper. If the gift wrap is rolled carefully, at zero angle, the ends of the paper will align with each side of the gift wrap tube. If the paper is wound carelessly, at an angle, the paper will overhang on one end of the tube.

The atomic structure and electronic behavior of each carbon nanotube is dictated by its wrapping angle, or chirality, and its diameter. The two traits are represented in a “(n,m)” numbering system that catalogs 466 varieties of nanotubes, each with a characteristic combination of chirality and diameter. Each (n,m) type of nanotube has a characteristic color.

Kauppinen’s research group has studied carbon nanotubes and nanotube thin films for years, and it previously succeeded in mastering the fabrication of colored nanotube thin films that appeared green, brown and silver-grey.

In the new study, Kauppinen’s team examined the relationship between the spectrum of absorbed light and the visual color of various thicknesses of dry nanotube films and developed a quantitative model that can unambiguously identify the coloration mechanism for nanotube films and predict the specific colors of films that combine tubes with different inherent colors and (n,m) designations.

Rice engineer and physicist Junichiro Kono, whose lab solved the mystery of colorful armchair nanotubes in 2012, provided films made solely of (6,5) nanotubes that were used to calibrate and verify the Aalto model. Researchers from Aalto and Peking universities used the model to calculate the absorption of the Rice film and its visual color. Experiments showed that the measured color of the film corresponded quite closely to the color forecast by the model.

The Aalto model shows that the thickness of a nanotube film, as well as the color of nanotubes it contains, affects the film’s absorption of light. Aalto’s atlas of 466 colors of nanotube films comes from combining different tubes. The research showed that the thinnest and most colorful tubes affect visible light more than those with larger diameters and faded colors.

“Esko’s group did an excellent job in theoretically explaining the colors, quantitatively, which really differentiates this work from previous studies on nanotube fluorescence and coloration,” Kono said.

Since 2013, Kono’s lab has pioneered a method for making highly ordered 2D nanotube films. Kono said he had hoped to supply Kauppinen’s team with highly ordered 2D crystalline films of nanotubes of a single chirality.

“That was the original idea, but unfortunately, we did not have appropriate single-chirality aligned films at that time,” Kono said. “In the future, our collaboration plans to extend this work to study polarization-dependent colors in highly ordered 2D crystalline films.”

The experimental method the Aalto researchers used to grow nanotubes for their films was the same as in their previous studies: Nanotubes grow from carbon monoxide gas and iron catalysts in a reactor that is heated to more than 850 degrees Celsius. The growth of nanotubes with different colors and (n,m) designations is regulated with the help of carbon dioxide that is added to the reactor.

“Since the previous study, we have pondered how we might explain the emergence of the colors of the nanotubes,” said Nan Wei, an assistant research professor at Peking University who previously worked as a postdoctoral researcher at Aalto. “Of the allotropes of carbon, graphite and charcoal are black, and pure diamonds are colorless to the human eye. However, now we noticed that single-walled carbon nanotubes can take on any color: for example, red, blue, green or brown.”

Kauppinen said colored thin films of nanotubes are pliable and ductile and could be useful in colored electronics structures and in solar cells.

“The color of a screen could be modified with the help of a tactile sensor in mobile phones, other touch screens or on top of window glass, for example,” he said.

Kauppinen said the research can also provide a foundation for new kinds of environmentally friendly dyes.

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

Colors of Single‐Wall Carbon Nanotubes by Nan Wei, Ying Tian, Yongping Liao, Natsumi Komatsu, Weilu Gao, Alina Lyuleeva‐Husemann, Qiang Zhang, Aqeel Hussain, Er‐Xiong Ding, Fengrui Yao, Janne Halme. Kaihui Liu, Junichiro Kono, Hua Jiang, Esko I. Kauppinen. Advanced Materials DOI: https://doi.org/10.1002/adma.202006395 First published: 14 December 2020

Thi8s paper is open access.

Colloidal quantum dots as ultra-sensitive hyper-spectral photodetectors

An October 16, 2019 news item on Nanowerk announces some of the latest work with colloidal quantum dots,

Researchers of the Optoelectronics and Measurement Techniques Unit (OPEM) at the University of Oulu [Finland] have invented a new method of producing ultra-sensitive hyper-spectral photodetectors. At the heart of the discovery are colloidal quantum dots, developed together with the researchers at the University of Toronto, Canada.

Quantum dots are tiny particles of 15-150 atoms of semiconducting material that have extraordinary optical and electrical properties due to quantum mechanics phenomena.

By controlling the size of the dots, the researchers are able to finetune how they react to different light colors (light wavelengths), especially those invisible for the human eye, namely the infrared spectrum.

The figure briefly introduces the concept of the study conducted by the researchers of the University of Oulu and the University of Toronto. The solution consisting of colloidal quantum dots is inkjet-printed, creating active photosensitive layer of the photodetector. Courtesy: Oulu University

An October 16, 2019 Oulu University press release, which originated the news item, provides more detail,

-Naturally, it is very rewarding that our hard work has been recognized by the international scientific community but at the same time, this report helps us to realize that there is a long journey ahead in incoming years. This publication is especially satisfying because it is the result of collaboration with world-class experts at the University of Toronto, Canada. This international collaboration where we combined the expertise of Toronto’s researchers in synthesizing quantum dots and our expertise in printed intelligence resulted in truly unique devices with astonishing performance, says docent Rafal Sliz, a leading researcher in this project.
 
Mastered in the OPEM unit, inkjet printing technology makes possible the creation of optoelectronic devices by designing functional inks that are printed on various surfaces, for instance, flexible substrates, clothing or human skin. Inkjet printing combined with colloidal quantum dots allowed the creation of photodetectors of impresive detectivity characteristics. The developed technology is a milestone in the creation of a new type of sub-micron-thick, flexible, and inexpensive IR sensing devices, the next generation of solar cells and other novel photonic systems.

-Oulus’ engineers and scientists’ strong expertise in optoelectronics resulted in many successful Oulu-based companies like Oura, Specim, Focalspec, Spectral Engines, and many more. New optoelectronic technologies, materials, and methods developed by our researchers will help Oulu and Finland to stay at the cutting edge of innovation, says professor Tapio Fabritius, a leader of the OPEM.

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

Stable Colloidal Quantum Dot Inks Enable Inkjet-Printed High-Sensitivity Infrared Photodetectors by Rafal Sliz, Marc Lejay, James Z. Fan, Min-Jae Choi, Sachin Kinge, Sjoerd Hoogland, Tapio Fabritius, F. Pelayo García de Arquer, Edward H. Sargent. ACS Nano 2019 DOI: https://doi.org/10.1021/acsnano.9b06125 Publication Date:September 23, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.

Achieving precise control by decorating iron nanocubes with gold

A June 17,2019 news item on phys.org describes a new technique for producing nanoparticles,

One of the major challenges in nanotechnology is the precise control of shape, size and elemental composition of every single nanoparticle. Physical methods are able to produce homogeneous nanoparticles free of surface contamination. However, they offer limited opportunity to control the shape and specific composition of the nanoobjects when they are being built up.

A recent collaboration between the University of Helsinki and the Okinawa Institute of Science and Technology (OIST) Graduate University revealed that hybrid Au/Fe nanoparticles can grow in an unprecedentedly complex structure with a single-step fabrication method. Using a computational modeling framework, the groups of Professor Flyura Djurabekova at the University of Helsinki and Prof. Sowwan at OIST succeeded in deciphering the growth mechanism by a detailed multistage model.

A June 14, 2019 University of Helsinki press release (also on EurekAlert but published June 17, 2019), which originated the news item, expands on the theme,

Elegantly combined considerations of kinetic and thermodynamic effects explained the formation of embedded gold layers and the site-specific surface gold decoration. These results open up a possibility for engineering a multitude of hybrid nanoparticles for a wide range of emerging applications. Their research was recently published in the highly ranked open access journal Advanced Science.

“When nature surprises us with an unexpectedly beautiful pattern, we must recognize it and explain. This is the way to cooperate with nature that is always ready to teach and expecting us to learn,” says Dr. Junlei Zhao, a postdoctoral researcher in the group of Prof. Djurabekova.

Nowadays, scientists are able to study nano-scale phenomena with great accuracy by using high-performance computational software and modern supercomputing infrastructures. These are of great support, not only for advancing fundamental science but also for finding promising solutions for many challenges of humanity.

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

Site‐Specific Wetting of Iron Nanocubes by Gold Atoms in Gas‐Phase Synthesis by Jerome Vernieres, Stephan Steinhauer, Junlei Zhao, Panagiotis Grammatikopoulos, Riccardo Ferrando, Kai Nordlund, Flyura Djurabekova, Mukhles Sowwan. Advanced Science Volume 6, Issue 13
1900447 uly 3, 2019 DOI: https://doi.org/10.1002/advs.201900447 First published online: 02 May 2019

This paper is open access.

Colo(u)ring your carbon nanotubes

Finnish research is highlighted in an August 28, 2018 news item on phys.org,

A method developed at Aalto University, Finland, can produce large quantities of pristine single-walled carbon nanotubes in select shades of the rainbow. The secret is a fine-tuned fabrication process—and a small dose of carbon dioxide. The films could find applications in touch screen technologies or as coating agents for new types of solar cells.

An August 28, 2018 Aalto University press release (also on EurekAlert), which originated the news item, provides more detail,

Samples of the colourful carbon nanotube thin films, as produced in the fabrication reactor. Image: Aalto University.
 

Single-walled carbon nanotubes, or sheets of one atom-thick layers of graphene rolled up into different sizes and shapes, have found many uses in electronics and new touch screen devices. By nature, carbon nanotubes are typically black or a dark grey.

In their new study published in the Journal of the American Chemical Society (JACS), Aalto University researchers present a way to control the fabrication of carbon nanotube thin films so that they display a variety of different colours—for instance, green, brown, or a silvery grey.

The researchers believe this is the first time that coloured carbon nanotubes have been produced by direct synthesis. Using their invention, the colour is induced straight away in the fabrication process, not by employing a range of purifying techniques on finished, synthesized tubes.

With direct synthesis, large quantities of clean sample materials can be produced while also avoiding damage to the product in the purifying process—which makes it the most attractive approach for applications.

‘In theory, these coloured thin films could be used to make touch screens with many different colours, or solar cells that display completely new types of optical properties,’ says Esko Kauppinen, Professor at Aalto University.

To get carbon structures to display colours is a feat in itself. The underlying techniques needed to enable the colouration also imply finely detailed control of the structure of the nanotube structures. Kauppinen and his team’s unique method, which uses aerosols of metal and carbon, allows them to carefully manipulate and control the nanotube structure directly from the fabrication process.

‘Growing carbon nanotubes is, in a way, like planting trees: we need seeds, feeds, and solar heat. For us, aerosol nanoparticles of iron work as a catalyst or seed, carbon monoxide as the source for carbon, so feed, and a reactor gives heat at a temperature more than 850 degrees Celsius,’ says Dr. Hua Jiang, Senior Scientist at Aalto University.

Professor Kauppinen’s group has a long history of using these very resources in their singular production method. To add to their repertoire, they have recently experimented with administering small doses of carbon dioxide into the fabrication process.

‘Carbon dioxide acts as a kind of graft material that we can use to tune the growth of carbon nanotubes of various colors,’ explains Jiang.

With an advanced electron diffraction technique, the researchers were able to find out the precise atomic scale structure of their thin films. They found that they have very narrow chirality distributions, meaning that the orientation of the honeycomb-lattice of the tubes’ walls is almost uniform throughout the sample. The chirality more or less dictates the electrical properties carbon nanotubes can have, as well as their colour.

The method developed at Aalto University promises a simple and highly scalable way to fabricate carbon nanotube thin films in high yields.

‘Usually you have to choose between mass production or having good control over the structure of carbon nanotubes. With our breakthrough, we can do both,’ trusts Dr. Qiang Zhang, a postdoctoral researcher in the group.

Follow-up work is already underway.

‘We want to understand the science of how the addition of carbon dioxide tunes the structure of the nanotubes and creates colours. Our aim is to achieve full control of the growing process so that single-walled carbon nanotubes could be used as building blocks for the next generation of nanoelectronics devices,’ says professor Kauppinen.

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

Direct Synthesis of Colorful Single-Walled Carbon Nanotube Thin Films by Yongping Liao, Hua Jiang, Nan Wei, Patrik Laiho, Qiang Zhang, Sabbir A. Khan, and Esko I. Kauppinen. J. Am. Chem. Soc., 2018, 140 (31), pp 9797–9800 DOI: 10.1021/jacs.8b05151 Publication Date (Web): July 26, 2018

Copyright © 2018 American Chemical Society

This paper appears to be open access.

For the curious, here’s a peek at the coloured carbon nanotube films,

 

Caption: Samples of the colorful carbon nanotube thin films, as produced in the fabrication reactor. Credit: Authors / Aalto University

Quantum entanglement in near-macroscopic objects

Researchers at Finland’s Aalto University seem excited in an April 25, 2018 news item on phys.org,

Perhaps the strangest prediction of quantum theory is entanglement, a phenomenon whereby two distant objects become intertwined in a manner that defies both classical physics and a common-sense understanding of reality. In 1935, Albert Einstein expressed his concern over this concept, referring to it as “spooky action at a distance.”

Today, entanglement is considered a cornerstone of quantum mechanics, and it is the key resource for a host of potentially transformative quantum technologies. Entanglement is, however, extremely fragile, and it has previously been observed only in microscopic systems such as light or atoms, and recently in superconducting electric circuits.

In work recently published in Nature, a team led by Prof. Mika Sillanpää at Aalto University in Finland has shown that entanglement of massive objects can be generated and detected.

The researchers managed to bring the motions of two individual vibrating drumheads—fabricated from metallic aluminium on a silicon chip—into an entangled quantum state. The macroscopic objects in the experiment are truly massive compared to the atomic scale—the circular drumheads have a diametre similar to the width of a thin human hair.

An April 20,2018 Aalto University press release (also on EurekAlert), which originated the news item, provides more detail,

‘The vibrating bodies are made to interact via a superconducting microwave circuit. The electromagnetic fields in the circuit carry away any thermal disturbances, leaving behind only the quantum mechanical vibrations’, says Professor Sillanpää, describing the experimental setup.

Eliminating all forms of external noise is crucial for the experiments, which is why they have to be conducted at extremely low temperatures near absolute zero, at –273 °C. Remarkably, the experimental approach allows the unusual state of entanglement to persist for long periods of time, in this case up to half an hour. In comparison, measurements on elementary particles have witnessed entanglement to last only tiny fractions of a second.

‘These measurements are challenging but extremely fascinating. In the future, we will attempt to teleport the mechanical vibrations. In quantum teleportation, properties of physical bodies can be transmitted across arbitrary distances using the channel of “spooky action at a distance”. We are still pretty far from Star Trek, though,’ says Dr. Caspar Ockeloen-Korppi, the lead author on the work, who also performed the measurements.

The results demonstrate that it is now possible to have control over the most delicate properties of objects whose size approaches the scale of our daily lives. The achievement opens doors for new kinds of quantum technologies, where the entangled drumheads could be used as routers or sensors. The finding also enables new studies of fundamental physics in, for example, the poorly understood interplay of gravity and quantum mechanics.

The team also included scientists from the University of New South Wales in Australia, the University of Chicago in the USA, and the University of Jyväskylä in Finland, whose theoretical innovations paved the way for the laboratory experiment.

An illustration has been made available,

An illustration of the 15-micrometre-wide drumheads prepared on silicon chips used in the experiment. The drumheads vibrate at a high ultrasound frequency, and the peculiar quantum state predicted by Einstein was created from the vibrations. Image: Aalto University / Petja Hyttinen & Olli Hanhirova, ARKH Architects.

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

Stabilized entanglement of massive mechanical oscillators by C. F. Ockeloen-Korppi, E. Damskägg, J.-M. Pirkkalainen, M. Asjad, A. A. Clerk, F. Massel, M. J. Woolley & M. A. Sillanpää. Nature volume 556, pages478–482 (2018) doi:10.1038/s41586-018-0038-x Published online: 25 April 2018

This paper is behind a paywall.

Equality doesn’t necessarily lead to greater women’s STEM (science, technology, engineering, and mathematics) participation?

It seems counter-intuitive but societies where women have achieved greater equality see less participation by women in STEM (science, technology, engineering and mathematics) than countries where women are treated differently. This rather stunning research was released on February 14, 2018 (yes, Valentine’s Day).

Women, equality, STEM

Both universities involved in this research have made news/press releases available. First, there’s the February 14, 2018 Leeds Beckett University (UK) press release,

Countries with greater gender equality see a smaller proportion of women taking degrees in science, technology, engineering and mathematics (STEM), a new study by Leeds Beckett has found.

Dubbed the ‘gender equality paradox’, the research found that countries such as Albania and Algeria have a greater percentage of women amongst their STEM graduates than countries lauded for their high levels of gender equality, such as Finland, Norway or Sweden.

The researchers, from Leeds Beckett’s School of Social Sciences and the University of Missouri, believe this might be because countries with less gender equality often have little welfare support, making the choice of a relatively highly-paid STEM career more attractive.

The study, published in Psychological Science, also looked at what might motivate girls and boys to choose to study STEM subjects, including overall ability, interest or enjoyment in the subject and whether science subjects were a personal academic strength.

Using data on 475,000 adolescents across 67 countries or regions, the researchers found that while boys’ and girls’ achievement in STEM subjects was broadly similar, science was more likely to be boys’ best subject.

Girls, even when their ability in science equalled or excelled that of boys, were often likely to be better overall in reading comprehension, which relates to higher ability in non-STEM subjects.

Girls also tended to register a lower interest in science subjects. These differences were near-universal across all the countries and regions studied.

This could explain some of the gender disparity in STEM participation, according to Leeds Beckett Professor in Psychology Gijsbert Stoet.

“The further you get in secondary and then higher education, the more subjects you need to drop until you end with just one.

“We are inclined to choose what we are best at and also enjoy. This makes sense and matches common school advice.

“So, even though girls can match boys in terms of how well they do at science and mathematics in school, if those aren’t their best subjects and they are less interested in them, then they’re likely to choose to study something else.”

The researchers also looked at how many girls might be expected to choose further study in STEM based on these criteria.

They took the number of girls in each country who had the necessary ability in STEM and for whom it was also their best subject and compared this to the number of women graduating in STEM.

They found there was a disparity in all countries, but with the gap once again larger in more gender equal countries.

In the UK, 29 per cent of STEM graduates are female, whereas 48 per cent of UK girls might be expected to take those subjects based on science ability alone. This drops to 39 per cent when both science ability and interest in the subject are taken into account.

Countries with higher gender equality tend also to be welfare states, providing a high level of social security for their citizens.

Professor Stoet said: “STEM careers are generally secure and well-paid but the risks of not following such a path can vary.

“In more affluent countries where any choice of career feels relatively safe, women may feel able to make choices based on non-economic factors.

“Conversely, in countries with fewer economic opportunities, or where employment might be precarious, a well-paid and relatively secure STEM career can be more attractive to women.”

Despite extensive efforts to increase participation of women in STEM, levels have remained broadly stable for decades, but these findings could help target interventions to make them more effective, say the researchers.

“It’s important to take into account that girls are choosing not to study STEM for what they feel are valid reasons, so campaigns that target all girls may be a waste of energy and resources,” said Professor Stoet.

“If governments want to increase women’s participation in STEM, a more effective strategy might be to target the girls who are clearly being ‘lost’ from the STEM pathway: those for whom science and maths are their best subjects and who enjoy it but still don’t choose it.

“If we can understand their motivations, then interventions can be designed to help them change their minds.”

Then, there’s the February 14, 2018 University of Missouri news release, some of which will be repetitive,

The underrepresentation of girls and women in science, technology, engineering and mathematics (STEM) fields occurs globally. Although women currently are well represented in life sciences, they continue to be underrepresented in inorganic sciences, such as computer science and physics. Now, researchers from the University of Missouri and Leeds Beckett University in the United Kingdom have found that as societies become wealthier and more gender equal, women are less likely to obtain degrees in STEM. The researchers call this a “gender-equality paradox.” Researchers also discovered a near-universal sex difference in academic strengths and weaknesses that contributes to the STEM gap. Findings from the study could help refine education efforts and policies geared toward encouraging girls and women with strengths in science or math to participate in STEM fields.

The researchers found that, throughout the world, boys’ academic strengths tend to be in science or mathematics, while girls’ strengths are in reading. Students who have personal strengths in science or math are more likely to enter STEM fields, whereas students with reading as a personal strength are more likely to enter non-STEM fields, according to David Geary, Curators Professor of Psychological Sciences in the MU College of Arts and Science. These sex differences in academic strengths, as well as interest in science, may explain why the sex differences in STEM fields has been stable for decades, and why current approaches to address them have failed.

“We analyzed data on 475,000 adolescents across 67 countries or regions and found that while boys’ and girls’ achievements in STEM subjects were broadly similar in all countries, science was more likely to be boys’ best subject,” Geary said. “Girls, even when their abilities in science equaled or excelled that of boys, often were likely to be better overall in reading comprehension, which relates to higher ability in non-STEM subjects. As a result, these girls tended to seek out other professions unrelated to STEM fields.”

Surprisingly, this trend was larger for girls and women living in countries with greater gender equality. The authors call this a “gender-equality paradox,” because countries lauded for their high levels of gender equality, such as Finland, Norway or Sweden, have relatively few women among their STEM graduates. In contrast, more socially conservative countries such as Turkey or Algeria have a much larger percentage of women among their STEM graduates.

“In countries with greater gender equality, women are actively encouraged to participate in STEM; yet, they lose more girls because of personal academic strengths,” Geary said. “In more liberal and wealthy countries, personal preferences are more strongly expressed. One consequence is that sex differences in academic strengths and interests become larger and have a stronger influence college and career choices than in more conservative and less wealthy countries, creating the gender-equality paradox.”

The combination of personal academic strengths in reading, lower interest in science, and broader financial security explains why so few women choose a STEM career in highly developed nations.

“STEM careers are generally secure and well-paid but the risks of not following such a path can vary,” said Gijsbert Stoet, Professor in Psychology at Leeds Beckett University. “In more affluent countries where any choice of career feels relatively safe, women may feel able to make choices based on non-economic factors. Conversely, in countries with fewer economic opportunities, or where employment might be precarious, a well-paid and relatively secure STEM career can be more attractive to women.”

Findings from this study could help target interventions to make them more effective, say the researchers. Policymakers should reconsider failing national policies focusing on decreasing the gender imbalance in STEM, the researchers add.

The University of Missouri also produced a brief video featuring Professor David Geary discussing the work,

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

The Gender-Equality Paradox in Science, Technology, Engineering, and Mathematics Education by Gijsbert Stoet, David C. Geary. Psychological Studies https://doi.org/10.1177/0956797617741719 First Published February 14, 2018 Research Article

This paper is behind a paywall.

Gender equality and STEM: a deeper dive

Olga Khazan in a February 18, 2018 article for The Atlantic provides additional insight (Note: Links have been removed),

Though their numbers are growing, only 27 percent of all students taking the AP Computer Science exam in the United States are female. The gender gap only grows worse from there: Just 18 percent of American computer-science college degrees go to women. This is in the United States, where many college men proudly describe themselves as “male feminists” and girls are taught they can be anything they want to be.

Meanwhile, in Algeria, 41 percent of college graduates in the fields of science, technology, engineering, and math—or “STEM,” as its known—are female. There, employment discrimination against women is rife and women are often pressured to make amends with their abusive husbands.

According to a report I covered a few years ago, Jordan, Qatar, and the United Arab Emirates were the only three countries in which boys are significantly less likely to feel comfortable working on math problems than girls are. In all of the other nations surveyed, girls were more likely to say they feel “helpless while performing a math problem.”

… this line of research, if it’s replicated, might hold useful takeaways for people who do want to see more Western women entering STEM fields. In this study, the percentage of girls who did excel in science or math was still larger than the number of women who were graduating with STEM degrees. That means there’s something in even the most liberal societies that’s nudging women away from math and science, even when those are their best subjects. The women-in-STEM advocates could, for starters, focus their efforts on those would-be STEM stars.

Final thoughts

This work upends notions (mine anyway) about equality and STEM with regard to women’s participation in countries usually described as ‘developed’ as opposed to ‘developing’. I am thankful to have my ideas shaken up and being forced to review my assumptions about STEM participation and equality of opportunity.

John Timmer in a February 19, 2018 posting on the Ars Technica blog offers a critique of the research and its conclusions,

… The countries where the science-degree gender gap is smaller tend to be less socially secure. The researchers suggest that the economic security provided by fields like engineering may have a stronger draw in these countries, pulling more women into the field.

They attempt to use a statistical pathway analysis to see if the data is consistent with this being the case, but the results are inconclusive. It may be right, but there would be at least one other strong factor that they have not identified involved.

Timmer’s piece is well worth reading.

For some reason the discussion about a lack of social safety nets and precarious conditions leading women to greater STEM participation reminds me of a truism about the arts. Constraints can force you into greater creativity. Although balance is necessary as you don’t want to destroy what you’re trying to encourage. In this case, it seems that comfortable lifestyles can lead women to pursue that which comes more easily whereas women trying to make a better life in difficult circumstance will pursue a more challenging path.

New breed of memristors?

This new ‘breed’ of memristor (a component in brain-like/neuromorphic computing) is a kind of thin film. First, here’s an explanation of neuromorphic computing from the Finnish researchers looking into a new kind of memristor, from a January 10, 2018 news item on Nanowerk,

The internet of things [IOT] is coming, that much we know. But still it won’t; not until we have components and chips that can handle the explosion of data that comes with IoT. In 2020, there will already be 50 billion industrial internet sensors in place all around us. A single autonomous device – a smart watch, a cleaning robot, or a driverless car – can produce gigabytes of data each day, whereas an airbus may have over 10 000 sensors in one wing alone.

Two hurdles need to be overcome. First, current transistors in computer chips must be miniaturized to the size of only few nanometres; the problem is they won’t work anymore then. Second, analysing and storing unprecedented amounts of data will require equally huge amounts of energy. Sayani Majumdar, Academy Fellow at Aalto University, along with her colleagues, is designing technology to tackle both issues.

Majumdar has with her colleagues designed and fabricated the basic building blocks of future components in what are called “neuromorphic” computers inspired by the human brain. It’s a field of research on which the largest ICT companies in the world and also the EU are investing heavily. Still, no one has yet come up with a nano-scale hardware architecture that could be scaled to industrial manufacture and use.

An Aalto University January 10, 2018 press release, which originated the news item, provides more detail about the work,

“The technology and design of neuromorphic computing is advancing more rapidly than its rival revolution, quantum computing. There is already wide speculation both in academia and company R&D about ways to inscribe heavy computing capabilities in the hardware of smart phones, tablets and laptops. The key is to achieve the extreme energy-efficiency of a biological brain and mimic the way neural networks process information through electric impulses,” explains Majumdar.

Basic components for computers that work like the brain

In their recent article in Advanced Functional Materials, Majumdar and her team show how they have fabricated a new breed of “ferroelectric tunnel junctions”, that is, few-nanometre-thick ferroelectric thin films sandwiched between two electrodes. They have abilities beyond existing technologies and bode well for energy-efficient and stable neuromorphic computing.

The junctions work in low voltages of less than five volts and with a variety of electrode materials – including silicon used in chips in most of our electronics. They also can retain data for more than 10 years without power and be manufactured in normal conditions.

Tunnel junctions have up to this point mostly been made of metal oxides and require 700 degree Celsius temperatures and high vacuums to manufacture. Ferroelectric materials also contain lead which makes them – and all our computers – a serious environmental hazard.

“Our junctions are made out of organic hydro-carbon materials and they would reduce the amount of toxic heavy metal waste in electronics. We can also make thousands of junctions a day in room temperature without them suffering from the water or oxygen in the air”, explains Majumdar.

What makes ferroelectric thin film components great for neuromorphic computers is their ability to switch between not only binary states – 0 and 1 – but a large number of intermediate states as well. This allows them to ‘memorise’ information not unlike the brain: to store it for a long time with minute amounts of energy and to retain the information they have once received – even after being switched off and on again.

We are no longer talking of transistors, but ‘memristors’. They are ideal for computation similar to that in biological brains.  Take for example the Mars 2020 Rover about to go chart the composition of another planet. For the Rover to work and process data on its own using only a single solar panel as an energy source, the unsupervised algorithms in it will need to use an artificial brain in the hardware.

“What we are striving for now, is to integrate millions of our tunnel junction memristors into a network on a one square centimetre area. We can expect to pack so many in such a small space because we have now achieved a record-high difference in the current between on and off-states in the junctions and that provides functional stability. The memristors could then perform complex tasks like image and pattern recognition and make decisions autonomously,” says Majumdar.

The probe-station device (the full instrument, left, and a closer view of the device connection, right) which measures the electrical responses of the basic components for computers mimicking the human brain. The tunnel junctions are on a thin film on the substrate plate. Photo: Tapio Reinekoski

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

Electrode Dependence of Tunneling Electroresistance and Switching Stability in Organic Ferroelectric P(VDF-TrFE)-Based Tunnel Junctions by Sayani Majumdar, Binbin Chen, Qi Hang Qin, Himadri S. Majumdar, and Sebastiaan van Dijken. Advanced Functional Materials Vol. 28 Issue 2 DOI: 10.1002/adfm.201703273 Version of Record online: 27 NOV 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Adopting robots into a health care system, Finnish style

The Finns have been studying the implementation of a logistics robotic system in a hospital setting according to an August 30, 2017 news item on phys.org,

VTT Technical Research Centre of Finland studied the implementation of a logistics robot system at the Seinäjoki Central Hospital in South Ostrobothnia. The aim is to reduce transportation costs, improve the availability of supplies and alleviate congestion on hospital hallways by running deliveries around the clock on every day of the week. Joint planning and dialogue between the various occupational groups and stakeholders involved was necessary for a successful change process.

This study is part of a larger project as the August 30, 2017 VTT press release (also on EurekAlert), which originated the news item, makes clear,

As the population ages, the need for robotic services is on the increase. Adopting new technology to support care and nursing work is not straightforward, however. Autonomous service robots and robot systems raise questions about safety as well as about their impact on care quality and jobs, among others.

VTT has studied the implementation of a next-generation logistics robot system at the Seinäjoki Central Hospital. First steps are being taken in Finland to introduce automated delivery systems in hospitals, with Seinäjoki Central Hospital acting as one of the pioneers. The Seinäjoki hospital’s robot system will include a total of 5–8 automated delivery robots, two of which were deployed during the study.

With deliveries running 24/7, the system will help to improve the availability of supplies and alleviate congestion on hallways. Experiences gained during the first six months show that transport personnel expenses and the physical strain of transport work have been reduced. The personnel’s views on the delivery robots have developed favourably and other hospitals have shown plenty of interest in the Seinäjoki hospital’s experiences.

From the perspective of various occupational groups, adoption of the system has had a varied effect on their perceived level of sense of control and appreciation of their work, as well as competence requirements. This study by VTT, employing work research approaches and a systems-oriented view, highlights the importance of taking into account in the change process the interdependencies between various players, along with their roles in the hospital’s core task.

Careful planning, piloting and implementation are required to ensure that the adoption of new robots runs smoothly as a whole. “As the system is expanded with new robots and types of deliveries, even more guidance, communication and dialogue is needed. Joint planning that brings various players to the same table ensures that the system’s implementation goes as smoothly as possible, making it easier to achieve the desired overall benefits”, says Senior Scientist Inka Lappalainen of the ROSE project.

VTT’s study is part of the Robots and the Future of Welfare Services project (ROSE), running from 2015 to 2020. The project investigates Finland’s opportunities for adopting assisting robotics to support the ageing population’s independent living, wellbeing and care. There is also a blog post on the topic: http://roseproject.aalto.fi/fi/blog/32-blog8.

Roadmap

Intermediate results of the project are presented in the publication Robotics in Care Services: A Finnish Roadmap, providing recommendations for both policy making and research. The roadmap is available on the ROSE project website, at http://roseproject.aalto.fi/ or http://roseproject.aalto.fi/fi/blog/29-roadmap-blog-fi.

The roadmap has been compiled by the project consortium comprising Aalto University, the project’s coordinator, and research organisations Laurea University of Applied Sciences, Lappeenranta University of Technology, Tampere University of Technology, University of Tampere and VTT.

 Photo: a logistics robot at the Seinäjoki Central Hospital (photo Marketta Niemelä, VTT)

To make it easier for those without Finnish language reading skills, I have a link to the English language version of the ROSE website. In looking at the ROSE website’s video page, I found this amongst others,

This reminded me of an initiative in Canada introducing a robot designed for use in clinical settings. In a July 4, 2017 posting, I posed this question,

A Canadian project to introduce robots like Pepper into clinical settings (aside: can seniors’ facilities be far behind?) is the subject of a June 23, 2017 news item on phys.org, …

There’s also been some work on robots and seniors in Holland (Netherlands) and Japan although I don’t have any details.

Bio-based standup pouches (food packaging) made from cellulose

CAPTION: VTT has developed lightweight 100% bio-based stand-up pouches with high technical performance. (Photo by VTT)

A March 14, 2017 news item on ScienceDaily describes a new nanocellulose-based product developed by the Technical Research Centre of Finland (VTT),

VTT Technical Research Centre of Finland Ltd has developed lightweight 100% bio-based stand-up pouches with high technical performance. High performance in both oxygen, grease and mineral oil barrier properties has been reached by using different biobased coatings on paper substrate. The pouches exploit VTT’s patent pending high consistency enzymatic fibrillation of cellulose (HefCel) technology.

A March 14, 2017 VTT press release (also on EurekAlert), which originated the news item, describes why the researchers want to change how food is packaged,

“One-third of food produced for human consumption is lost or wasted globally. Packaging with efficient barrier properties is a crucial factor in the reduction of the food loss. Our solution offers an environmentally friendly option for the global packaging industry”, says Senior Scientist Jari Vartiainen of VTT.

VTT’s HefCel technology provides a low-cost method for the production of nanocellulose resulting in a tenfold increase in the solids content of nanocellulose. Nanocellulose has been shown to be potentially very useful for a number of future technical applications. The densely packed structure of nanocellulose films and coatings enable their outstanding oxygen, grease and mineral oil barrier properties.

HefCel technology exploits industrial enzymes and simple mixing technology as tools to fibrillate cellulose into nanoscale fibrils without the need for high energy consuming process steps. The resulting nanocellulose is in the consistency of 15-25% when traditional nanocellulose production methods result in 1-3% consistency.

The stand-up pouch is the fastest growing type of packaging, growing at a rate of 6.5% per year from 2015-2020. Fossil-based plastic films still dominate the packaging market. However, the development of environmentally friendly new materials is of growing importance. Nanocellulose has been shown to be potentially very useful for a number of future technical applications.

VTT has solid expertise in various bio-based raw materials and their application technologies for producing bio-based coatings, films and even multilayered structures both at lab-scale and pilot-scale. A versatile set of piloting facilities are available from raw material sourcing through processing to application testing and demonstration.

I’m glad to hear they’re finding uses for nanocellulose and I keep wondering when Canadian scientists who at one point were leaders in developing crystal nanocellulose (CNC or sometimes known as nanocrystalline cellulose [NCC]) will be making announcements about potential products.

Harvesting plants for electricity

A Feb. 27, 2017 article on Nanowerk describes research which could turn living plants into solar cells and panels (Note: Links have been removed),

Plants power life on Earth. They are the original food source supplying energy to almost all living organisms and the basis of the fossil fuels that feed the power demands of the modern world. But burning the remnants of long-dead forests is changing the world in dangerous ways. Can we better harness the power of living plants today?

One way might be to turn plants into natural solar power stations that could convert sunlight into energy far more efficiently. To do this, we’d need a way of getting the energy out in the form of electricity. One company has found a way to harvest electrons deposited by plants into the soil beneath them. But new research (PNAS, “In vivo polymerization and manufacturing of wires and supercapacitors in plants”) from Finland looks at tapping plants’ energy directly by turning their internal structures into electric circuits.

A Feb. 27, 2017 essay by Stuart Thompson for The Conversation (which originated the article) explains the principles underlying the research (Note: A link has been removed),

Plants contain water-filled tubes called “xylem elements” that carry water from their roots to their leaves. The water flow also carries and distributes dissolved nutrients and other things such as chemical signals. The Finnish researchers, whose work is published in PNAS, developed a chemical that was fed into a rose cutting to form a solid material that could carry and store electricity.

Previous experiments have used a chemical called PEDOT to form conducting wires in the xylem, but it didn’t penetrate further into the plant. For the new research, they designed a molecule called ETE-S that forms similar electrical conductors but can also be carried wherever the stream of water travelling though the xylem goes.

This flow is driven by the attraction between water molecules. When water in a leaf evaporates, it pulls on the chain of molecules left behind, dragging water up through the plant all the way from the roots. You can see this for yourself by placing a plant cutting in food colouring and watching the colour move up through the xylem. The researchers’ method was so similar to the food colouring experiment that they could see where in the plant their electrical conductor had travelled to from its colour.

The result was a complex electronic network permeating the leaves and petals, surrounding their cells and replicating their pattern. The wires that formed conducted electricity up to a hundred times better than those made from PEDOT and could also store electrical energy in the same way as an electronic component called a capacitor.

I recommend reading Thompson’s piece in its entirety.