Tag Archives: University of Bristol

Moths with sound absorption stealth technology

The cabbage tree emperor moth (Thomas Neil) [downloaded from https://www.cbc.ca/radio/quirks/nov-17-2018-greenland-asteroid-impact-short-people-in-the-rain-forest-reef-islands-and-sea-level-and-more-1.4906857/how-moths-evolved-a-kind-of-stealth-jet-technology-to-sneak-past-bats-1.4906866]

I don’t think I’ve ever seen a more gorgeous moth and it seems a perfect way to enter 2019, from a November 16, 2018 news item on CBC (Canadian Broadcasting Corporation),

A species of silk moth has evolved special sound absorbing scales on its wings to absorb the sonar pulses from hunting bats. This is analogous to the special coatings on stealth aircraft that allow them to be nearly invisible to radar.

“It’s a battle out there every night, insects flying for their lives trying to avoid becoming a bat’s next dinner,” said Dr. Marc Holderied, the senior author on the paper and an associate professor in the School of Biological Sciences at the University of Bristol.

“If you manage to absorb some of these sound energies, it would make you look smaller and let you be detectable over a shorter distance because echoe isn’t strong enough outside the detection bubble.”

Many moths have ears that warn them when a bat is nearby. But not the big and juicy cabbage tree emperor moths which would ordinarily make the perfect meal for bats.

The researchers prepared a brief animated feature illustrating the research,

Prior to publication of the study, the scientists made a presentation at the Acoustical Society of America’s 176th Meeting, held in conjunction with the Canadian Acoustical Association’s 2018 Acoustics Week, Nov. 5-9 at the Victoria Conference Centre in Victoria, Canada according to a November 7, 2018 University of Bristol press release (also on EurekAlert but submitted by the Acoustical Society of America on November 6, 2018),

Moths are a mainstay food source for bats, which use echolocation (biological sonar) to hunt their prey. Scientists such as Thomas Neil, from the University of Bristol in the U.K., are studying how moths have evolved passive defenses over millions of years to resist their primary predators.

While some moths have evolved ears that detect the ultrasonic calls of bats, many types of moths remain deaf. In those moths, Neil has found that the insects developed types of “stealth coating” that serve as acoustic camouflage to evade hungry bats.

Neil will describe his work during the Acoustical Society of America’s 176th Meeting, held in conjunction with the Canadian Acoustical Association’s 2018 Acoustics Week, Nov. 5-9 at the Victoria Conference Centre in Victoria, Canada.

In his presentation, Neil will focus on how fur on a moth’s thorax and wing joints provide acoustic stealth by reducing the echoes of these body parts from bat calls.

“Thoracic fur provides substantial acoustic stealth at all ecologically relevant ultrasonic frequencies,” said Neil, a researcher at Bristol University. “The thorax fur of moths acts as a lightweight porous sound absorber, facilitating acoustic camouflage and offering a significant survival advantage against bats.” Removing the fur from the moth’s thorax increased its detection risk by as much as 38 percent.

Neil used acoustic tomography to quantify echo strength in the spatial and frequency domains of two deaf moth species that are subject to bat predation and two butterfly species that are not.

In comparing the effects of removing thorax fur from insects that serve as food for bats to those that don’t, Neil’s research team found that thoracic fur determines acoustic camouflage of moths but not butterflies.

“We found that the fur on moths was both thicker and denser than that of the butterflies, and these parameters seem to be linked with the absorptive performance of their respective furs,” Neil said. “The thorax fur of the moths was able to absorb up to 85 percent of the impinging sound energy. The maximum absorption we found in butterflies was just 20 percent.”

Neil’s research could contribute to the development of biomimetic materials for ultrathin sound absorbers and other noise-control devices.

“Moth fur is thin and lightweight,” said Neil, “and acts as a broadband and multidirectional ultrasound absorber that is on par with the performance of current porous sound-absorbing foams.”

Moth fur? This has changed my view of moths although I reserve the right to get cranky when local moths chew through my wool sweaters. Here’s a link to and a citation for the paper,

Biomechanics of a moth scale at ultrasonic frequencies by Zhiyuan Shen, Thomas R. Neil, Daniel Robert, Bruce W. Drinkwater, and Marc W. Holderied. PNAS [Proccedings of the National Academy of Sciences of the United States of America] November 27, 2018 115 (48) 12200-12205; published ahead of print November 12, 2018 https://doi.org/10.1073/pnas.1810025115

This paper is behind a paywall.

Unusually I’m going to include the paper’s abstract here,

The wings of moths and butterflies are densely covered in scales that exhibit intricate shapes and sculptured nanostructures. While certain butterfly scales create nanoscale photonic effects [emphasis mine], moth scales show different nanostructures suggesting different functionality. Here we investigate moth-scale vibrodynamics to understand their role in creating acoustic camouflage against bat echolocation, where scales on wings provide ultrasound absorber functionality. For this, individual scales can be considered as building blocks with adapted biomechanical properties at ultrasonic frequencies. The 3D nanostructure of a full Bunaea alcinoe moth forewing scale was characterized using confocal microscopy. Structurally, this scale is double layered and endowed with different perforation rates on the upper and lower laminae, which are interconnected by trabeculae pillars. From these observations a parameterized model of the scale’s nanostructure was formed and its effective elastic stiffness matrix extracted. Macroscale numerical modeling of scale vibrodynamics showed close qualitative and quantitative agreement with scanning laser Doppler vibrometry measurement of this scale’s oscillations, suggesting that the governing biomechanics have been captured accurately. Importantly, this scale of B. alcinoe exhibits its first three resonances in the typical echolocation frequency range of bats, suggesting it has evolved as a resonant absorber. Damping coefficients of the moth-scale resonator and ultrasonic absorption of a scaled wing were estimated using numerical modeling. The calculated absorption coefficient of 0.50 agrees with the published maximum acoustic effect of wing scaling. Understanding scale vibroacoustic behavior helps create macroscopic structures with the capacity for broadband acoustic camouflage.

Those nanoscale photonic effects caused by butterfly scales are something I’d usually describe as optical effects due to the nanoscale structures on some butterfly wings, notably those of the Blue Morpho butterfly. In fact there’s a whole field of study on what’s known as structural colo(u)r. Strictly speaking I’m not sure you could describe the nanostructures on Glasswing butterflies as an example of structure colour since those structures make that butterfly’s wings transparent but they are definitely an optical effect. For the curious, you can use ‘blue morpho butterfly’, ‘glasswing butterfly’ or ‘structural colo(u)r’ to search for more on this blog or pursue bigger fish with an internet search.

Tractor beams for humans?

I got excited for a moment before realizing that, if tractor beams for humans result from this work, it will be many years in the future. Still, one can dream, eh? Here’s more about the current state of tractor beams (the acoustic kind) from a January 21, 2018 news item on ScienceDaily,

Acoustic tractor beams use the power of sound to hold particles in mid-air, and unlike magnetic levitation, they can grab most solids or liquids. For the first time University of Bristol engineers have shown it is possible to stably trap objects larger than the wavelength of sound in an acoustic tractor beam. This discovery opens the door to the manipulation of drug capsules or micro-surgical implements within the body. Container-less transportation of delicate larger samples is now also a possibility and could lead to levitating humans.

A January 22, 2018 University of Bristol press release (also on EurekAlert but dated January 21, 2018), which originated the news item, expands on the theme,

Researchers previously thought that acoustic tractor beams were fundamentally limited to levitating small objects as all the previous attempts to trap particles larger than the wavelength had been unstable, with objects spinning uncontrollably. This is because rotating sound field transfers some of its spinning motion to the objects causing them to orbit faster and faster until they are ejected.

The new approach, published in Physical Review Letters today [Monday 22 January]{2018}], uses rapidly fluctuating acoustic vortices, which are similar to tornadoes of sound, made of a twister-like structure with loud sound surrounding a silent core.

The Bristol researchers discovered that the rate of rotation can be finely controlled by rapidly changing the twisting direction of the vortices, this stabilises the tractor beam. They were then able to increase the size of the silent core allowing it to hold larger objects. Working with ultrasonic waves at a pitch of 40kHz, a similar pitch to that which only bats can hear, the researchers held a two-centimetre polystyrene sphere in the tractor beam. This sphere measures over two acoustic wavelengths in size and is the largest yet trapped in a tractor beam. The research suggests that, in the future much larger objects could be levitated in this way.

Dr Asier Marzo, lead author on the paper from Bristol’s Department of Mechanical Engineering, said: “Acoustic researchers had been frustrated by the size limit for years, so its satisfying to find a way to overcome it. I think it opens the door to many new applications.”

Dr Mihai Caleap, Senior Research Associate, who developed the simulations, explained: “In the future, with more acoustic power it will be possible to hold even larger objects. This was only thought to be possible using lower pitches making the experiment audible and dangerous for humans.”

Bruce Drinkwater, Professor of Ultrasonics from the Department of Mechanical Engineering, who supervised the work, added: “Acoustic tractor beams have huge potential in many applications. I’m particularly excited by the idea of contactless production lines where delicate objects are assembled without touching them.”

The researchers have included a video representing their work,

I always liked the tractor beams on Star Trek as they seemed very useful. For those who can dream in more technical language, here’s a link to and a citation for the paper,

Acoustic Virtual Vortices with Tunable Orbital Angular Momentum for Trapping of Mie Particles by Asier Marzo, Mihai Caleap, and Bruce W. Drinkwater. Phys. Rev. Lett. Vol. 120, Iss. 4 — 26 January 2018 DOI:https://doi.org/10.1103/PhysRevLett.120.044301 Published 22 January 2018

This paper is open access.

Nanotechnology cracks Wall Street (Daily)

David Dittman’s Jan. 11, 2017 article for wallstreetdaily.com portrays a great deal of excitement about nanotechnology and the possibilities (I’m highlighting the article because it showcases Dexter Johnson’s Nanoclast blog),

When we talk about next-generation aircraft, next-generation wearable biomedical devices, and next-generation fiber-optic communication, the consistent theme is nano: nanotechnology, nanomaterials, nanophotonics.

For decades, manufacturers have used carbon fiber to make lighter sports equipment, stronger aircraft, and better textiles.

Now, as Dexter Johnson of IEEE [Institute of Electrical and Electronics Engineers] Spectrum reports [on his Nanoclast blog], carbon nanotubes will help make aerospace composites more efficient:

Now researchers at the University of Surrey’s Advanced Technology Institute (ATI), the University of Bristol’s Advanced Composite Centre for Innovation and Science (ACCIS), and aerospace company Bombardier [headquartered in Montréal, Canada] have collaborated on the development of a carbon nanotube-enabled material set to replace the polymer sizing. The reinforced polymers produced with this new material have enhanced electrical and thermal conductivity, opening up new functional possibilities. It will be possible, say the British researchers, to embed gadgets such as sensors and energy harvesters directly into the material.

When it comes to flight, lighter is better, so building sensors and energy harvesters into the body of aircraft marks a significant leap forward.

Johnson also reports for IEEE Spectrum on a “novel hybrid nanomaterial” based on oscillations of electrons — a major advance in nanophotonics:

Researchers at the University of Texas at Austin have developed a hybrid nanomaterial that enables the writing, erasing and rewriting of optical components. The researchers believe that this nanomaterial and the techniques used in exploiting it could create a new generation of optical chips and circuits.

Of course, the concept of rewritable optics is not altogether new; it forms the basis of optical storage mediums like CDs and DVDs. However, CDs and DVDs require bulky light sources, optical media and light detectors. The advantage of the rewritable integrated photonic circuits developed here is that it all happens on a 2-D material.

“To develop rewritable integrated nanophotonic circuits, one has to be able to confine light within a 2-D plane, where the light can travel in the plane over a long distance and be arbitrarily controlled in terms of its propagation direction, amplitude, frequency and phase,” explained Yuebing Zheng, a professor at the University of Texas who led the research… “Our material, which is a hybrid, makes it possible to develop rewritable integrated nanophotonic circuits.”

Who knew that mixing graphene with homemade Silly Putty would create a potentially groundbreaking new material that could make “wearables” actually useful?

Next-generation biomedical devices will undoubtedly include some of this stuff:

A dash of graphene can transform the stretchy goo known as Silly Putty into a pressure sensor able to monitor a human pulse or even track the dainty steps of a small spider.

The material, dubbed G-putty, could be developed into a device that continuously monitors blood pressure, its inventors hope.

The guys who made G-putty often rely on “household stuff” in their research.

It’s nice to see a blogger’s work be highlighted. Congratulations Dexter.

G-putty was mentioned here in a Dec. 30, 2016 posting which also includes a link to Dexter’s piece on the topic.

Soft contact lenses key to supercapacitor breaththrough

It seems like pretty exciting news for anyone following the supercapacitor story but they are being awfully cagey about it all in a Dec. 6, 2016 news item on Nanowerk,

Ground-breaking research from the University of Surrey and Augmented Optics Ltd., in collaboration with the University of Bristol, has developed potentially transformational technology which could revolutionise the capabilities of appliances that have previously relied on battery power to work.

This development by Augmented Optics Ltd., could translate into very high energy density super-capacitors making it possible to recharge your mobile phone, laptop or other mobile devices in just a few seconds.

The technology could have a seismic impact across a number of industries, including transport, aerospace, energy generation, and household applications such as mobile phones, flat screen electronic devices, and biosensors. It could also revolutionise electric cars, allowing the possibility for them to recharge as quickly as it takes for a regular non-electric car to refuel with petrol – a process that currently takes approximately 6-8 hours to recharge. Imagine, instead of an electric car being limited to a drive from London to Brighton, the new technology could allow the electric car to travel from London to Edinburgh without the need to recharge, but when it did recharge for this operation to take just a few minutes to perform.

I imagine the reason for the caginess has to do with the efforts to commercialize the technology. In any event, here’s a little more from a Dec. 5, 2016 University of Surrey press release by Ashley Lovell,

Supercapacitor buses are already being used in China, but they have a very limited range whereas this technology could allow them to travel a lot further between recharges. Instead of recharging every 2-3 stops this technology could mean they only need to recharge every 20-30 stops and that will only take a few seconds.

Elon Musk, of Tesla and SpaceX, has previously stated his belief that supercapacitors are likely to be the technology for future electric air transportation. We believe that the present scientific advance could make that vision a reality.

The technology was adapted from the principles used to make soft contact lenses, which Dr Donald Highgate (of Augmented Optics, and an alumnus of the University of Surrey) developed following his postgraduate studies at Surrey 40 years ago. Supercapacitors, an alternative power source to batteries, store energy using electrodes and electrolytes and both charge and deliver energy quickly, unlike conventional batteries which do so in a much slower, more sustained way. Supercapacitors have the ability to charge and discharge rapidly over very large numbers of cycles. However, because of their poor energy density per kilogramme (approximately just one twentieth of existing battery technology), they have, until now, been unable to compete with conventional battery energy storage in many applications.

Dr Brendan Howlin of the University of Surrey, explained: “There is a global search for new energy storage technology and this new ultra capacity supercapacitor has the potential to open the door to unimaginably exciting developments.”

The ground-breaking research programme was conducted by researchers at the University of Surrey’s Department of Chemistry where the project was initiated by Dr Donald Highgate of Augmented Optics Ltd. The research team was co-led by the Principal Investigators Dr Ian Hamerton and Dr Brendan Howlin. Dr Hamerton continues to collaborate on the project in his new post at the University of Bristol, where the electrochemical testing to trial the research findings was carried out by fellow University of Bristol academic – David Fermin, Professor of Electrochemistry in the School of Chemistry.

Dr Ian Hamerton, Reader in Polymers and Composite Materials from the Department of Aerospace Engineering, University of Bristol said: “While this research has potentially opened the route to very high density supercapacitors, these *polymers have many other possible uses in which tough, flexible conducting materials are desirable, including bioelectronics, sensors, wearable electronics, and advanced optics. We believe that this is an extremely exciting and potentially game changing development.”

*the materials are based on large organic molecules composed of many repeated sub-units and bonded together to form a 3-dimensional network.

Jim Heathcote, Chief Executive of both Augmented Optics Ltd and Supercapacitor Materials Ltd, said: “It is a privilege to work with the teams from the University of Surrey and the University of Bristol. The test results from the new polymers suggest that extremely high energy density supercapacitors could be constructed in the very new future. We are now actively seeking commercial partners [emphasis mine] in order to supply our polymers and offer assistance to build these ultra high energy density storage devices.”

I was not able to find a website for Augmented Optics but there is one for SuperCapacitor Materials here.

D-PLACE: an open access database of places, language, culture, and enviroment

In an attempt to be a bit more broad in my interpretation of the ‘society’ part of my commentary I’m including this July 8, 2016 news item on ScienceDaily (Note: A link has been removed),

An international team of researchers has developed a website at d-place.org to help answer long-standing questions about the forces that shaped human cultural diversity.

D-PLACE — the Database of Places, Language, Culture and Environment — is an expandable, open access database that brings together a dispersed body of information on the language, geography, culture and environment of more than 1,400 human societies. It comprises information mainly on pre-industrial societies that were described by ethnographers in the 19th and early 20th centuries.

A July 8, 2016 University of Toronto news release (also on EurekAlert), which originated the news item, expands on the theme,

“Human cultural diversity is expressed in numerous ways: from the foods we eat and the houses we build, to our religious practices and political organisation, to who we marry and the types of games we teach our children,” said Kathryn Kirby, a postdoctoral fellow in the Departments of Ecology & Evolutionary Biology and Geography at the University of Toronto and lead author of the study. “Cultural practices vary across space and time, but the factors and processes that drive cultural change and shape patterns of diversity remain largely unknown.

“D-PLACE will enable a whole new generation of scholars to answer these long-standing questions about the forces that have shaped human cultural diversity.”

Co-author Fiona Jordan, senior lecturer in anthropology at the University of Bristol and one of the project leads said, “Comparative research is critical for understanding the processes behind cultural diversity. Over a century of anthropological research around the globe has given us a rich resource for understanding the diversity of humanity – but bringing different resources and datasets together has been a huge challenge in the past.

“We’ve drawn on the emerging big data sets from ecology, and combined these with cultural and linguistic data so researchers can visualise diversity at a glance, and download data to analyse in their own projects.”

D-PLACE allows users to search by cultural practice (e.g., monogamy vs. polygamy), environmental variable (e.g. elevation, mean annual temperature), language family (e.g. Indo-European, Austronesian), or region (e.g. Siberia). The search results can be displayed on a map, a language tree or in a table, and can also be downloaded for further analysis.

It aims to enable researchers to investigate the extent to which patterns in cultural diversity are shaped by different forces, including shared history, demographics, migration/diffusion, cultural innovations, and environmental and ecological conditions.

D-PLACE was developed by an international team of scientists interested in cross-cultural research. It includes researchers from Max Planck Institute for the Science of Human history in Jena Germany, University of Auckland, Colorado State University, University of Toronto, University of Bristol, Yale, Human Relations Area Files, Washington University in Saint Louis, University of Michigan, American Museum of Natural History, and City University of New York.

The diverse team included: linguists; anthropologists; biogeographers; data scientists; ethnobiologists; and evolutionary ecologists, who employ a variety of research methods including field-based primary data collection; compilation of cross-cultural data sources; and analyses of existing cross-cultural datasets.

“The team’s diversity is reflected in D-PLACE, which is designed to appeal to a broad user base,” said Kirby. “Envisioned users range from members of the public world-wide interested in comparing their cultural practices with those of other groups, to cross-cultural researchers interested in pushing the boundaries of existing research into the drivers of cultural change.”

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

D-PLACE: A Global Database of Cultural, Linguistic and Environmental Diversity by Kathryn R. Kirby, Russell D. Gray, Simon J. Greenhill, Fiona M. Jordan, Stephanie Gomes-Ng, Hans-Jörg Bibiko, Damián E. Blasi, Carlos A. Botero, Claire Bowern, Carol R. Ember, Dan Leehr, Bobbi S. Low, Joe McCarter, William Divale, Michael C. Gavin.  PLOS ONE, 2016; 11 (7): e0158391 DOI: 10.1371/journal.pone.0158391 Published July 8, 2016.

This paper is open access.

You can find D-PLACE here.

While it might not seem like that there would be a close link between anthropology and physics in the 19th and early 20th centuries, that information can be mined for more contemporary applications. For example, someone who wants to make a case for a more diverse scientific community may want to develop a social science approach to the discussion. The situation in my June 16, 2016 post titled: Science literacy, science advice, the US Supreme Court, and Britain’s House of Commons, could  be extended into a discussion and educational process using data from D-Place and other sources to make the point,

Science literacy may not be just for the public, it would seem that US Supreme Court judges may not have a basic understanding of how science works. David Bruggeman’s March 24, 2016 posting (on his Pasco Phronesis blog) describes a then current case before the Supreme Court (Justice Antonin Scalia has since died), Note: Links have been removed,

It’s a case concerning aspects of the University of Texas admissions process for undergraduates and the case is seen as a possible means of restricting race-based considerations for admission.  While I think the arguments in the case will likely revolve around factors far removed from science and or technology, there were comments raised by two Justices that struck a nerve with many scientists and engineers.

Both Justice Antonin Scalia and Chief Justice John Roberts raised questions about the validity of having diversity where science and scientists are concerned [emphasis mine].  Justice Scalia seemed to imply that diversity wasn’t esential for the University of Texas as most African-American scientists didn’t come from schools at the level of the University of Texas (considered the best university in Texas).  Chief Justice Roberts was a bit more plain about not understanding the benefits of diversity.  He stated, “What unique perspective does a black student bring to a class in physics?”

To that end, Dr. S. James Gates, theoretical physicist at the University of Maryland, and member of the President’s Council of Advisers on Science and Technology (and commercial actor) has an editorial in the March 25 [2016] issue of Science explaining that the value of having diversity in science does not accrue *just* to those who are underrepresented.

Dr. Gates relates his personal experience as a researcher and teacher of how people’s background inform their practice of science, and that two different people may use the same scientific method, but think about the problem differently.

I’m guessing that both Scalia and Roberts and possibly others believe that science is the discovery and accumulation of facts. In this worldview science facts such as gravity are waiting for discovery and formulation into a ‘law’. They do not recognize that most science is a collection of beliefs and may be influenced by personal beliefs. For example, we believe we’ve proved the existence of the Higgs boson but no one associated with the research has ever stated unequivocally that it exists.

More generally, with D-PLACE and the recently announced Trans-Atlantic Platform (see my July 15, 2016 post about it), it seems Canada’s humanities and social sciences communities are taking strides toward greater international collaboration and a more profound investment in digital scholarship.

Cardiac pacemakers: Korea’s in vivo demonstration of a self-powered one* and UK’s breath-based approach

As i best I can determine ,the last mention of a self-powered pacemaker and the like on this blog was in a Nov. 5, 2012 posting (Developing self-powered batteries for pacemakers). This latest news from The Korea Advanced Institute of Science and Technology (KAIST) is, I believe, the first time that such a device has been successfully tested in vivo. From a June 23, 2014 news item on ScienceDaily,

As the number of pacemakers implanted each year reaches into the millions worldwide, improving the lifespan of pacemaker batteries has been of great concern for developers and manufacturers. Currently, pacemaker batteries last seven years on average, requiring frequent replacements, which may pose patients to a potential risk involved in medical procedures.

A research team from the Korea Advanced Institute of Science and Technology (KAIST), headed by Professor Keon Jae Lee of the Department of Materials Science and Engineering at KAIST and Professor Boyoung Joung, M.D. of the Division of Cardiology at Severance Hospital of Yonsei University, has developed a self-powered artificial cardiac pacemaker that is operated semi-permanently by a flexible piezoelectric nanogenerator.

A June 23, 2014 KAIST news release on EurekAlert, which originated the news item, provides more details,

The artificial cardiac pacemaker is widely acknowledged as medical equipment that is integrated into the human body to regulate the heartbeats through electrical stimulation to contract the cardiac muscles of people who suffer from arrhythmia. However, repeated surgeries to replace pacemaker batteries have exposed elderly patients to health risks such as infections or severe bleeding during operations.

The team’s newly designed flexible piezoelectric nanogenerator directly stimulated a living rat’s heart using electrical energy converted from the small body movements of the rat. This technology could facilitate the use of self-powered flexible energy harvesters, not only prolonging the lifetime of cardiac pacemakers but also realizing real-time heart monitoring.

The research team fabricated high-performance flexible nanogenerators utilizing a bulk single-crystal PMN-PT thin film (iBULe Photonics). The harvested energy reached up to 8.2 V and 0.22 mA by bending and pushing motions, which were high enough values to directly stimulate the rat’s heart.

Professor Keon Jae Lee said:

“For clinical purposes, the current achievement will benefit the development of self-powered cardiac pacemakers as well as prevent heart attacks via the real-time diagnosis of heart arrhythmia. In addition, the flexible piezoelectric nanogenerator could also be utilized as an electrical source for various implantable medical devices.”

This image illustrating a self-powered nanogenerator for a cardiac pacemaker has been provided by KAIST,

This picture shows that a self-powered cardiac pacemaker is enabled by a flexible piezoelectric energy harvester. Credit: KAIST

This picture shows that a self-powered cardiac pacemaker is enabled by a flexible piezoelectric energy harvester.
Credit: KAIST

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

Self-Powered Cardiac Pacemaker Enabled by Flexible Single Crystalline PMN-PT Piezoelectric Energy Harvester by Geon-Tae Hwang, Hyewon Park, Jeong-Ho Lee, SeKwon Oh, Kwi-Il Park, Myunghwan Byun, Hyelim Park, Gun Ahn, Chang Kyu Jeong, Kwangsoo No, HyukSang Kwon, Sang-Goo Lee, Boyoung Joung, and Keon Jae Lee. Advanced Materials DOI: 10.1002/adma.201400562
Article first published online: 17 APR 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

There was a May 15, 2014 KAIST news release on EurekAlert announcing this same piece of research but from a technical perspective,

The energy efficiency of KAIST’s piezoelectric nanogenerator has increased by almost 40 times, one step closer toward the commercialization of flexible energy harvesters that can supply power infinitely to wearable, implantable electronic devices

NANOGENERATORS are innovative self-powered energy harvesters that convert kinetic energy created from vibrational and mechanical sources into electrical power, removing the need of external circuits or batteries for electronic devices. This innovation is vital in realizing sustainable energy generation in isolated, inaccessible, or indoor environments and even in the human body.

Nanogenerators, a flexible and lightweight energy harvester on a plastic substrate, can scavenge energy from the extremely tiny movements of natural resources and human body such as wind, water flow, heartbeats, and diaphragm and respiration activities to generate electrical signals. The generators are not only self-powered, flexible devices but also can provide permanent power sources to implantable biomedical devices, including cardiac pacemakers and deep brain stimulators.

However, poor energy efficiency and a complex fabrication process have posed challenges to the commercialization of nanogenerators. Keon Jae Lee, Associate Professor of Materials Science and Engineering at KAIST, and his colleagues have recently proposed a solution by developing a robust technique to transfer a high-quality piezoelectric thin film from bulk sapphire substrates to plastic substrates using laser lift-off (LLO).

Applying the inorganic-based laser lift-off (LLO) process, the research team produced a large-area PZT thin film nanogenerators on flexible substrates (2 cm x 2 cm).

“We were able to convert a high-output performance of ~250 V from the slight mechanical deformation of a single thin plastic substrate. Such output power is just enough to turn on 100 LED lights,” Keon Jae Lee explained.

The self-powered nanogenerators can also work with finger and foot motions. For example, under the irregular and slight bending motions of a human finger, the measured current signals had a high electric power of ~8.7 μA. In addition, the piezoelectric nanogenerator has world-record power conversion efficiency, almost 40 times higher than previously reported similar research results, solving the drawbacks related to the fabrication complexity and low energy efficiency.

Lee further commented,

“Building on this concept, it is highly expected that tiny mechanical motions, including human body movements of muscle contraction and relaxation, can be readily converted into electrical energy and, furthermore, acted as eternal power sources.”

The research team is currently studying a method to build three-dimensional stacking of flexible piezoelectric thin films to enhance output power, as well as conducting a clinical experiment with a flexible nanogenerator.

In addition to the 2012 posting I mentioned earlier, there was also this July 12, 2010 posting which described research on harvesting biomechanical movement ( heart beat, blood flow, muscle stretching, or even irregular vibration) at the Georgia (US) Institute of Technology where the lead researcher observed,

…  Wang [Professor Zhong Lin Wang at Georgia Tech] tells Nanowerk. “However, the applications of the nanogenerators under in vivo and in vitro environments are distinct. Some crucial problems need to be addressed before using these devices in the human body, such as biocompatibility and toxicity.”

Bravo to the KAIST researchers for getting this research to the in vivo testing stage.

Meanwhile at the University of Bristol and at the University of Bath, researchers have received funding for a new approach to cardiac pacemakers, designed them with the breath in mind. From a June 24, 2014 news item on Azonano,

Pacemaker research from the Universities of Bath and Bristol could revolutionise the lives of over 750,000 people who live with heart failure in the UK.

The British Heart Foundation (BHF) is awarding funding to researchers developing a new type of heart pacemaker that modulates its pulses to match breathing rates.

A June 23, 2014 University of Bristol press release, which originated the news item, provides some context,

During 2012-13 in England, more than 40,000 patients had a pacemaker fitted.

Currently, the pulses from pacemakers are set at a constant rate when fitted which doesn’t replicate the natural beating of the human heart.

The normal healthy variation in heart rate during breathing is lost in cardiovascular disease and is an indicator for sleep apnoea, cardiac arrhythmia, hypertension, heart failure and sudden cardiac death.

The device is then briefly described (from the press release),

The novel device being developed by scientists at the Universities of Bath and Bristol uses synthetic neural technology to restore this natural variation of heart rate with lung inflation, and is targeted towards patients with heart failure.

The device works by saving the heart energy, improving its pumping efficiency and enhancing blood flow to the heart muscle itself.  Pre-clinical trials suggest the device gives a 25 per cent increase in the pumping ability, which is expected to extend the life of patients with heart failure.

One aim of the project is to miniaturise the pacemaker device to the size of a postage stamp and to develop an implant that could be used in humans within five years.

Dr Alain Nogaret, Senior Lecturer in Physics at the University of Bath, explained“This is a multidisciplinary project with strong translational value.  By combining fundamental science and nanotechnology we will be able to deliver a unique treatment for heart failure which is not currently addressed by mainstream cardiac rhythm management devices.”

The research team has already patented the technology and is working with NHS consultants at the Bristol Heart Institute, the University of California at San Diego and the University of Auckland. [emphasis mine]

Professor Julian Paton, from the University of Bristol, added: “We’ve known for almost 80 years that the heart beat is modulated by breathing but we have never fully understood the benefits this brings. The generous new funding from the BHF will allow us to reinstate this natural occurring synchrony between heart rate and breathing and understand how it brings therapy to hearts that are failing.”

Professor Jeremy Pearson, Associate Medical Director at the BHF, said: “This study is a novel and exciting first step towards a new generation of smarter pacemakers. More and more people are living with heart failure so our funding in this area is crucial. The work from this innovative research team could have a real impact on heart failure patients’ lives in the future.”

Given some current events (‘Tesla opens up its patents’, Mike Masnick’s June 12, 2014 posting on Techdirt), I wonder what the situation will be vis à vis patents by the time this device gets to market.

* ‘one’ added to title on Aug. 13, 2014.

Camouflage for everyone

The Institute of Physics (IOP) journal, Bioinspiration and BIomimetics, has published an open access article on camouflage inspired by zebrafish and squid. From the IOP’s May 2, 2012 news release

Researchers from the University of Bristol have created artificial muscles that can be transformed at the flick of a switch to mimic the remarkable camouflaging abilities of organisms such as squid and zebrafish.

They demonstrate two individual transforming mechanisms that they believe could be used in ‘smart clothing’ to trigger camouflaging tricks similar to those seen in nature.

The soft, stretchy, artificial muscles are based on specialist cells called chromatophores that are found in amphibians, fish, reptiles and cephalopods, and contain pigments of colours that are responsible for the animals’ remarkable colour-changing effects.

Here’s the video mentioned in the IOP’s May 2, 2012 news release,

The lead author Jonathan Rossiter provides a description of the work (which may help you better understand what you’re seeing on the video), from the May 2, 2012 news item,

Two types of artificial chromatophores were created in the study: the first based on a mechanism adopted by a squid and the second based on a rather different mechanism adopted by zebrafish.

A typical colour-changing cell in a squid has a central sac containing granules of pigment. The sac is surrounded by a series of muscles and when the cell is ready to change colour, the brain sends a signal to the muscles and they contract. The contracting muscles make the central sacs expand, generating the optical effect which makes the squid look like it is changing colour.

The fast expansion of these muscles was mimicked using dielectric elastomers (DEs) – smart materials, usually made of a polymer, which are connected to an electric circuit and expand when a voltage is applied. They return to their original shape when they are short circuited.

In contrast, the cells in the zebrafish contain a small reservoir of black pigmented fluid that, when activated, travels to the skin surface and spreads out, much like the spilling of black ink. The natural dark spots on the surface of the zebrafish therefore appear to get bigger and the desired optical effect is achieved. The changes are usually driven by hormones.

The zebrafish cells were mimicked using two glass microscope slides sandwiching a silicone layer. Two pumps, made from flexible DEs, were positioned on both sides of the slide and were connected to the central system with silicone tubes; one pumping opaque white spirit, the other a mixture of black ink and water.

“Our artificial chromatophores are both scalable and adaptable and can be made into an artificial compliant skin which can stretch and deform, yet still operate effectively. This means they can be used in many environments where conventional ‘hard’ technologies would be dangerous, for example at the physical interface with humans, such as smart clothing,” continued Rossiter.

I wonder what these smart clothes/smart skin would feel like against your personal skin given that we are talking about ‘artificial muscles’. For example, how much movement would your clothing/smart skin have independent of you?

By independent, I mean that everything occurs externally. While we’re not ordinarily conscious of all our physical responses they are stimulated internally and part of a whole body response (even though we may notice only localized responses, e.g., a rash). In the research, there’s an external stimulus and an external response via smart clothes/smart skin.

This is just speculation as I imagine we’re several years away from any field testing of these smart clothes/smart skin, assuming that scientists are able to address all the technical hurdles between a laboratory breakthrough and developing applications.

Thanks to Nanowerk where I first came across this information (May 2, 2012 news item).

Magna Carta for nano?

The more I investigated this Nano Carta news item on Nanowerk, March 14, 2012, the more confused I’ve become. Here’s the easy part,

Part of a Europe-wide debate about the ethical, social and legal questions associated with nanoscience will take place in Bristol on Tuesday [20 March, 2012].

The debate, featuring a group of Bristol University PhD students from the Bristol Centre for Functional Nanomaterials [BCFN], will help form an ethical code for nanotechnology looking at privacy issues, acceptance, human health, access, liability, regulation and control.

Pupils in Years 10 and 11 at St Mary Redcliffe and Temple School will input their own thoughts after learning about nanotechnology – the study of manipulating matter on an atomic and molecular scale – as part of an on-going partnership with the University.

The Nanochannels project is funded by the European Commission and involves 20 teachers from eight countries across the continent, each engaging students through the use of social media such as Facebook, Twitter and live debates. The Guardian newspaper is a partner in the project and is publishing articles on its Nanotechnology World microsite.

Dr Paul Hill, a science teacher at St Mary Redcliffe, won the grant and established the collaboration with the BCFN. Postgraduate students have since been teaching pupils about the theory and practical challenges of researching nanotechnology, with examples from their own PhD research.

Here’s the press release from the University of Bristol announcing the event.

It all got rather confusing when I started reading about the event elsewhere. The Scientix website notes the UK event is part of a larger series, which started in Tel Aviv (no mention of Nano Cartas or any other Cartas),

Nanochannels School Debate series started

Published on: 31/01/2012

Country: United Kingdom

Topic: Nanotechnology,  Project,  Event

Target groups: college students,  general public,  policy makers,  primary school students,  secondary school students,  teachers,  trainee teachers

Two school debates in Tel Aviv, Israel, kicked off the series of live discussions among students, researchers, NGOs, industry and the public on the risks and benefits of the use of nanotechnologies in our everyday life.

The Nano Channels website lists all of the events in this series of live debates which range from Israel (as noted) to the UK, France, Italy, Romania, Turkey, Germany, and Austria.

The topic listed for the March 20,  2012 debate for St. Mary Redcliffe and Temple School is listed as ‘Nano sensors for medical diagnostics’.

I then found an announcement of a March 13, 2012 event in this series held in Italy which does mention the Nano Carta, also on the Scientix website,

Nanochannels Live School Debate – Pavullo nel Frignano

Location: Pavullo nel Frignano

Country: Italy

Type of event: Debate

Organizer: Nanochannels

Project: Nanochannels

Target groups: general public,  industry,  primary school students,  researchers,  secondary school students,  teachers,  trainee teachers

Topic: Nanotechnology,  Education

Language of event: Italian

A live “role play” debate among students, also with participation from researchers, NGOs, the nanotechnology (NT) industry and the general public, who will discuss a specific issue concerning nanotechnologies and their use in our everyday life.

The outcome of the debate will be a “Nanocarta”, a summary of the debate produced by the students, which will be posted on the Nanochannels website and in social media. Over the school year the Nanochannels students will produce press articles with help from professional journalists. The best ones will be co-edited and published by the Nanochannels press partners: The Guardian, El Mundo and Corriere della Sera.

The debate is organised by the Nanochannel project and its partner school in Pavullo nel Frignano (Italy). The project aims to design and undertake a programme of communication on nanotechnology through a variety of media channels and outreach events.

My best guess is that they are focusing on specific topics in the schools so students can get a grasp of some basic nanotechnology concepts before embarking on a debate about larger issues such as ethics and social impacts.

(I have written about the Nanochannels project previously in my June 14, 2011 posting.)

Finally, I thought it would be interesting to get a definition of the Magna Carta (from the Wikipedia essay),

Magna Carta, also called Magna Carta Libertatum, is an English charter, originally issued in the year 1215 and reissued later in the 13th century in modified versions. The later versions excluded the most direct challenges to the monarch’s authority that had been present in the 1215 charter. The charter first passed into law in 1225; the 1297 version, with the long title (originally in Latin) The Great Charter of the Liberties of England, and of the Liberties of the Forest, still remains on the statute books of England and Wales.

The 1215 charter required King John of England to proclaim certain liberties, and accept that his will was not arbitrary, for example by explicitly accepting that no “freeman” (in the sense of non-serf) could be punished except through the law of the land, a right which is still in existence today.

If there’s a Nano Carta and following on the definition of the Magna Carta, whose will is not arbitrary and in what circumstance? Are nanoparticles being ceded rights? I’m being facetious but I hope they do approach these debates in an imaginative way and with questions that might seem ridiculous as that’s often the best way to stimulate new thinking and ideas.