Tag Archives: National University of Singapore (NUS)

A snout weevil at the end of the rainbow

I’ve never heard of a snout weevil before but it seems to be a marvelous creature,

Caption: Left: A photograph of the ‘rainbow’ weevil, with the rainbow-colored spots on its thorax and elytra (wing casings). Right: A microscope image of the rim of a single rainbow spot, showing the different colors of individual scales. Credit: Dr Bodo D Wilts

From a Sept. 11, 2018 news item on Nanowerk,

Researchers from Yale [University]-NUS College and the University of Fribourg in Switzerland have discovered a novel colour-generation mechanism in nature, which if harnessed, has the potential to create cosmetics and paints with purer and more vivid hues, screen displays that project the same true image when viewed from any angle, and even reduce the signal loss in optical fibres.

Yale-NUS College Assistant Professor of Science (Life Science) Vinodkumar Saranathan led the study with Dr Bodo D Wilts from the Adolphe Merkle Institute at the University of Fribourg. Dr Saranathan examined the rainbow-coloured patterns in the elytra (wing casings) of a snout weevil from the Philippines, Pachyrrhynchus congestus pavonius, using high-energy X-rays, while Dr Wilts performed detailed scanning electron microscopy and optical modelling.

They discovered that to produce the rainbow palette of colours, the weevil utilised a colour-generation mechanism that is so far found only in squid, cuttlefish, and octopuses, which are renowned for their colour-shifting camouflage.

A Sept. 11, 2018 Yale-NUS College news release (also on EurekAlert), which originated the news item, offers more on the weevil and on the research,

P. c. pavonius, or the “Rainbow” Weevil, is distinctive for its rainbow-coloured spots on its thorax and elytra (see attached image). These spots are made up of nearly-circular scales arranged in concentric rings of different hues, ranging from blue in the centre to red at the outside, just like a rainbow. While many insects have the ability to produce one or two colours, it is rare that a single insect can produce such a vast spectrum of colours. Researchers are interested to figure out the mechanism behind the natural formation of these colour-generating structures, as current technology is unable to synthesise structures of this size.

“The ultimate aim of research in this field is to figure out how the weevil self-assembles these structures, because with our current technology we are unable to do so,” Dr Saranathan said. “The ability to produce these structures, which are able to provide a high colour fidelity regardless of the angle you view it from, will have applications in any industry which deals with colour production. We can use these structures in cosmetics and other pigmentations to ensure high-fidelity hues, or in digital displays in your phone or tablet which will allow you to view it from any angle and see the same true image without any colour distortion. We can even use them to make reflective cladding for optical fibres to minimise signal loss during transmission.”

Dr Saranathan and Dr Wilts examined these scales to determine that the scales were composed of a three-dimensional crystalline structure made from chitin (the main ingredient in insect exoskeletons). They discovered that the vibrant rainbow colours on this weevil’s scales are determined by two factors: the size of the crystal structure which makes up each scale, as well as the volume of chitin used to make up the crystal structure. Larger scales have a larger crystalline structure and use a larger volume of chitin to reflect red light; smaller scales have a smaller crystalline structure and use a smaller volume of chitin to reflect blue light. According to Dr Saranathan, who previously examined over 100 species of insects and spiders and catalogued their colour-generation mechanisms, this ability to simultaneously control both size and volume factors to fine-tune the colour produced has never before been shown in insects, and given its complexity, is quite remarkable. “It is different from the usual strategy employed by nature to produce various different hues on the same animal, where the chitin structures are of fixed size and volume, and different colours are generated by orienting the structure at different angles, which reflects different wavelengths of light,” Dr Saranathan explained.

The research was partly supported though the National Centre of Competence in Research “Bio-Inspired Materials” and the Ambizione program of the Swiss National Science Foundation (SNSF) to Dr Wilts, and partly through a UK Royal Society Newton Fellowship, a Linacre College EPA Cephalosporin Junior Research Fellowship, and Yale-NUS College funds to Dr Saranathan. Dr Saranathan is currently part of a research team led by Yale-NUS College Associate Professor of Science Antonia Monteiro, which has recently been awarded a separate Competitive Research Programme (CRP) grant by Singapore’s National Research Foundation (NRF) to examine the genetic basis of the colour-generation mechanism in butterflies. Dr Saranathan and Dr Monteiro are both also from the Department of Biological Sciences at the National University of Singapore (NUS) Faculty of Science. In addition, Dr Saranathan is affiliated with the NUS Nanoscience and Nanotechnology Initiative.

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

Literal Elytral Rainbow: Tunable Structural Colors Using Single Diamond Biophotonic Crystals in Pachyrrhynchus congestus Weevils by Bodo D. Wilts, Vinodkumar Saranathan. Samll https://doi.org/10.1002/smll.201802328 First published: 15 August 2018

This paper is behind a paywall.

Nanoplastics accumulating in marine organisms

I’m starting to have a collection of postings related to plastic nanoparticles and aquatic life (I have a listing below). The latest originates in Singapore (from a May 31, 2018 news item on ScienceDaily),

Plastic nanoparticles — these are tiny pieces of plastic less than 1 micrometre in size — could potentially contaminate food chains, and ultimately affect human health, according to a recent study by scientists from the National University of Singapore (NUS). They discovered that nanoplastics are easily ingested by marine organisms, and they accumulate in the organisms over time, with a risk of being transferred up the food chain, threatening food safety and posing health risks.

A May 31, 2018 NUS press release (also on EurekAlert), which originated the news item, expands on the theme,

Ocean plastic pollution is a huge and growing global problem. It is estimated that the oceans may already contain over 150 million tonnes of plastic, and each year, about eight million tonnes of plastic will end up in the ocean. Plastics do not degrade easily. In the marine environment, plastics are usually broken down into smaller pieces by the sun, waves, wind and microbial action. These micro- and nanoplastic particles in the water may be ingested by filter-feeding marine organisms such as barnacles, tube worms and sea-squirts.

Using the acorn barnacle Amphibalanus amphitrite as a model organism, the NUS research team demonstrated for the first time that nanoplastics consumed during the larval stage are retained and accumulated inside the barnacle larvae until they reach adulthood.

“We opted to study acorn barnacles as their short life cycle and transparent bodies made it easy to track and visualise the movement of nanoplastics in their bodies within a short span of time,” said Mr Samarth Bhargava, a PhD student from the Department of Chemistry at the NUS Faculty of Science, who is the first author of the research paper.

“Barnacles can be found in all of the world’s oceans. This accumulation of nanoplastics within the barnacles is of concern. Further work is needed to better understand how they may contribute to longer term effects on marine ecosystems,” said Dr Serena Teo, Senior Research Fellow from the Tropical Marine Science Institute at NUS, who co-supervised the research.

Studying the fate of nanoplastics in marine organisms

The NUS research team incubated the barnacle larvae in solutions of their regular feed coupled with plastics that are about 200 nanometres in size with green fluorescent tags. The larvae were exposed to two different treatments: ‘acute’ and ‘chronic’.

Under the ‘acute’ treatment, the barnacle larvae were kept for three hours in a solution that contained 25 times more nanoplastics than current estimates of what is present in the oceans. On the other hand, under the ‘chronic’ treatment, the barnacle larvae were exposed to a solution containing low concentrations of nanoplastics for up to four days.

The larvae were subsequently filtered from the solution, and examined under the microscope. The distribution and movement of the nanoplastics were monitored by examining the fluorescence from the particles present within the larvae over time.

“Our results showed that after exposing the barnacle larvae to nanoplastics in both treatments, the larvae had not only ingested the plastic particles, but the tiny particles were found to be distributed throughout the bodies of the larvae,” said Ms Serina Lee from the Tropical Marine Science Institute at NUS, who is the second author of the paper.

Even though the barnacles’ natural waste removal pathways of moulting and excretion resulted in some removal of the nanoplastics, the team detected the continued presence of nanoplastics inside the barnacles throughout their growth until they reached adulthood.

“Barnacles may be at the lower levels of the food chain, but what they consume will be transferred to the organisms that eat them. In addition, plastics are capable of absorbing pollutants and chemicals from the water. These toxins may be transferred to the organisms if the particles of plastics are consumed, and can cause further damage to marine ecosystems and human health,” said marine biologist Dr Neo Mei Lin from the Tropical Marine Science Institute at NUS, who is one of the authors of the paper.

The team’s research findings were first published online in the journal ACS Sustainable Chemistry & Engineering in March 2018. The study was funded under the Marine Science Research and Development Programme of the National Research Foundation Singapore.

Next steps

The NUS research team seeks to further their understanding of the translocation of nanoparticles within the marine organisms and potential pathways of transfer in the marine ecosystem.

“The life span and fate of plastic waste materials in marine environment is a big concern at the moment owing to the large amounts of plastic waste and its potential impact on marine ecosystem and food security around the world. The team would like to explore such topics in the near future and possibly to come up with pathways to address such problems,” explained Associate Professor Suresh Valiyaveettil from the Department of Chemistry at the NUS Faculty of Science, who co-supervised the research.

The team is currently examining how nanoplastics affect other invertebrate model organisms to understand the impact of plastics on marine ecosystems.

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

Fate of Nanoplastics in Marine Larvae: A Case Study Using Barnacles, Amphibalanus amphitrite by Samarth Bhargava, Serina Siew Chen Lee, Lynette Shu Min Ying, Mei Lin Neo, Serena Lay-Ming Teo, and Suresh Valiyaveettil. ACS Sustainable Chem. Eng., 2018, 6 (5), pp 6932–6940 DOI: 10.1021/acssuschemeng.8b00766 Publication Date (Web): March 21, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Other plastic nanoparticle postings:

While this doesn’t relate directly to aquatic life, the research focuses on how plastic degrades into plastic nanoparticles,

That’s it for now.

Ecologically friendly air-conditioning that generates drinking water—Yes!

A team at the National University of Singapore (NUS) is looking for industry partners to help take their air-conditioning technology from the laboratory to the marketplace. First, here’s more about the technology from a January 8, 2018 news item on ScienceDaily,

A team of researchers from the National University of Singapore (NUS) has pioneered a new water-based air-conditioning system that cools air to as low as 18 degrees Celsius without the use of energy-intensive compressors and environmentally harmful chemical refrigerants. This game-changing technology could potentially replace the century-old air-cooling principle that is still being used in our modern-day air-conditioners. Suitable for both indoor and outdoor use, the novel system is portable and it can also be customised for all types of weather conditions.

A January 8, 2018 NUS press release offers additional technical detail and includes call for industrial partners,

2018-0108-Air-con.jpg

NUS Engineering researchers developed a novel air cooling technology that could redefine the future of air-conditioning.

Led by Associate Professor Ernest Chua from the Department of Mechanical Engineering at NUS Faculty of Engineering, the team’s novel air-conditioning system is cost-effective to produce, and it is also more eco-friendly and sustainable. The system consumes about 40 per cent less electricity than current compressor-based air-conditioners used in homes and commercial buildings. This translates into more than 40 per cent reduction in carbon emissions. In addition, it adopts a water-based cooling technology instead of using chemical refrigerants such as chlorofluorocarbon and hydrochlorofluorocarbon for cooling, thus making it safer and more environmentally-friendly.

To add another feather to its eco-friendliness cap, the novel system generates potable drinking water while it cools ambient air.

Assoc Prof Chua said, “For buildings located in the tropics, more than 40 per cent of the building’s energy consumption is attributed to air-conditioning. We expect this rate to increase dramatically, adding an extra punch to global warming. First invented by Willis Carrier in 1902, vapour compression air-conditioning is the most widely used air-conditioning technology today. This approach is very energy-intensive and environmentally harmful. In contrast, our novel membrane and water-based cooling technology is very eco-friendly – it can provide cool and dry air without using a compressor and chemical refrigerants. This is a new starting point for the next generation of air-conditioners, and our technology has immense potential to disrupt how air-conditioning has traditionally been provided.

Innovative membrane and water-based cooling technology

Current air-conditioning systems require a large amount of energy to remove moisture and to cool the dehumidified air. By developing two systems to perform these two processes separately, the NUS Engineering team can better control each process and hence achieve greater energy efficiency.

The novel air-conditioning system first uses an innovative membrane technology – a paper-like material – to remove moisture from humid outdoor air. The dehumidified air is then cooled via a dew-point cooling system that uses water as the cooling medium instead of harmful chemical refrigerants. Unlike vapour compression air-conditioners, the novel system does not release hot air to the environment. Instead, a cool air stream that is comparatively less humid than environmental humidity is discharged – negating the effect of micro-climate. About 12 to 15 litres of potable drinking water can also be harvested after operating the air-conditioning system for a day.

“Our cooling technology can be easily tailored for all types of weather conditions, from humid climate in the tropics to arid climate in the deserts. While it can be used for indoor living and commercial spaces, it can also be easily scaled up to provide air-conditioning for clusters of buildings in an energy-efficient manner. This novel technology is also highly suitable for confined spaces such as bomb shelters or bunkers, where removing moisture from the air is critical for human comfort, as well as for sustainable operation of delicate equipment in areas such as field hospitals, armoured personnel carriers, and operation decks of navy ships as well as aircrafts,” explained Assoc Prof Chua.

The research team is currently refining the design of the air-conditioning system to further improve its user-friendliness. The NUS researchers are also working to incorporate smart features such as pre-programmed thermal settings based on human occupancy and real-time tracking of its energy efficiency. The team hopes to work with industry partners to commercialise the technology. [emphasis mine]

This project is supported by the Building and Construction Authority and National Research Foundation Singapore.

I’m sorry they didn’t include a link to a published paper but I gather that at this time there’s more focus on commercializing the technology than on published papers. I wish the researchers good luck as this cooling technology affords some exciting possibilities in a world that is heating and growing more parched as the NUS press release.notes

Skyrmions and ultra-thin multilayer film

The National University of Singapore (NUS) and skyrmions are featured in an April 10, 2017 news item on phys.org,

A team of scientists led by Associate Professor Yang Hyunsoo from the Department of Electrical and Computer Engineering at the National University of Singapore’s (NUS) Faculty of Engineering has invented a novel ultra-thin multilayer film which could harness the properties of tiny magnetic whirls, known as skyrmions, as information carriers for storing and processing data on magnetic media.

The nano-sized thin film, which was developed in collaboration with researchers from Brookhaven National Laboratory, Stony Brook University, and Louisiana State University, is a critical step towards the design of data storage devices that use less power and work faster than existing memory technologies. The invention was reported in prestigious scientific journal Nature Communications on 10 March 2017.

An April 10, 2017 NUS press release on EurekAlert, which originated the news item, describes the work in more detail,

Tiny magnetic whirls with huge potential as information carriers

The digital transformation has resulted in ever-increasing demands for better processing and storing of large amounts of data, as well as improvements in hard drive technology. Since their discovery in magnetic materials in 2009, skyrmions, which are tiny swirling magnetic textures only a few nanometres in size, have been extensively studied as possible information carriers in next-generation data storage and logic devices.

Skyrmions have been shown to exist in layered systems, with a heavy metal placed beneath a ferromagnetic material. Due to the interaction between the different materials, an interfacial symmetry breaking interaction, known as the Dzyaloshinskii-Moriya interaction (DMI), is formed, and this helps to stabilise a skyrmion. However, without an out-of-plane magnetic field present, the stability of the skyrmion is compromised. In addition, due to its tiny size, it is difficult to image the nano-sized materials.

To address these limitations, the researchers worked towards creating stable magnetic skyrmions at room temperature without the need for a biasing magnetic field.

Unique material for data storage

The NUS team, which also comprises Dr Shawn Pollard and Ms Yu Jiawei from the NUS Department of Electrical and Computer Engineering, found that a large DMI could be maintained in multilayer films composed of cobalt and palladium, and this is large enough to stabilise skyrmion spin textures.

In order to image the magnetic structure of these films, the NUS researchers, in collaboration with Brookhaven National Laboratory in the United States, employed Lorentz transmission electron microscopy (L-TEM). L-TEM has the ability to image magnetic structures below 10 nanometres, but it has not been used to observe skyrmions in multilayer geometries previously as it was predicted to exhibit zero signal. However, when conducting the experiments, the researchers found that by tilting the films with respect to the electron beam, they found that they could obtain clear contrast consistent with that expected for skyrmions, with sizes below 100 nanometres.

Dr Pollard explained, “It has long been assumed that there is no DMI in a symmetric structure like the one present in our work, hence, there will be no skyrmion. It is really unexpected for us to find both large DMI and skyrmions in the multilayer film we engineered. What’s more, these nanoscale skyrmions persisted even after the removal of an external biasing magnetic field, which are the first of their kind.”

Assoc Prof Yang added, “This experiment not only demonstrates the usefulness of L-TEM in studying these systems, but also opens up a completely new material in which skyrmions can be created. Without the need for a biasing field, the design and implementation of skyrmion based devices are significantly simplified. The small size of the skyrmions, combined with the incredible stability generated here, could be potentially useful for the design of next-generation spintronic devices that are energy efficient and can outperform current memory technologies.”

Next step

Assoc Prof Yang and his team are currently looking at how nanoscale skyrmions interact with each other and with electrical currents, to further the development of skyrmion based electronics.

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

Observation of stable Néel skyrmions in cobalt/palladium multilayers with Lorentz transmission electron microscopy by Shawn D. Pollard, Joseph A. Garlow, Jiawei Yu, Zhen Wang, Yimei Zhu & Hyunsoo Yang. Nature Communications 8, Article number: 14761 (2017) doi:10.1038/ncomms14761 Published online: 10 March 2017

This is an open access paper.

Graphene Malaysia 2016 gathering and Malaysia’s National Graphene Action Plan 2020

Malaysia is getting ready to host a graphene conference according to an Oct. 10, 2016 news item on Nanotechnology Now,

The Graphene Malaysia 2016 [Nov. 8 – 9, 2016] (www.graphenemalaysiaconf.com) is jointly organized by NanoMalaysia Berhad and Phantoms Foundation. The conference will be centered on graphene industry interaction and collaborative innovation. The event will be launched under the National Graphene Action Plan 2020 (NGAP 2020), which will generate about 9,000 jobs and RM20 (US$4.86) billion GNI impact by the year 2020.

First speakers announced:
Murni Ali (Nanomalaysia, Malaysia) | Francesco Bonaccorso (Istituto Italiano di Tecnologia, Italy) | Antonio Castro Neto (NUS, Singapore) | Antonio Correia (Phantoms Foundation, Spain)| Pedro Gomez-Romero (ICN2 (CSIC-BIST), Spain) | Shu-Jen Han (Nanoscale Science & Technology IBM T.J. Watson Research Center, USA) | Kuan-Tsae Huang (AzTrong, USA/Taiwan) | Krzysztof Koziol (FGV Cambridge Nanosystems, UK) | Taavi Madiberk (Skeleton Technologies, Estonia) | Richard Mckie (BAE Systems, UK) | Pontus Nordin (Saab AB, Saab Aeronautics, Sweden) | Elena Polyakova (Graphene Laboratories Inc., USA) | Ahmad Khairuddin Abdul Rahim (Malaysian Investment Development Authority (MIDA), Malaysia) | Adisorn Tuantranont (Thailand Organic and Printed Electronics Innovation Center, Thailand) |Archana Venugopal (Texas Instruments, USA) | Won Jong Yoo (Samsung-SKKU Graphene-2D Center (SSGC), South Korea) | Hongwei Zhu (Tsinghua University, China)

You can check for more information and deadlines in the Nanotechnology Now Oct. 10, 2016 news item.

The Graphene Malalysia 2016 conference website can be found here and Malaysia’s National Graphene Action Plan 2020, which is well written, can be found here (PDF).  This portion from the executive summary offers some insight into Malyasia’s plans to launch itself into the world of high income nations,

Malaysia’s aspiration to become a high-income nation by 2020 with improved jobs and better outputs is driving the country’s shift away from “business as usual,” and towards more innovative and high value add products. Within this context, and in accordance with National policies and guidelines, Graphene, an emerging, highly versatile carbon-based nanomaterial, presents a unique opportunity for Malaysia to develop a high value economic ecosystem within its industries.  Isolated only in 2004, Graphene’s superior physical properties such as electrical/ thermal conductivity, high strength and high optical transparency, combined with its manufacturability have raised tremendous possibilities for its application across several functions and make it highly interesting for several applications and industries.  Currently, Graphene is still early in its development cycle, affording Malaysian companies time to develop their own applications instead of relying on international intellectual property and licenses.

Considering the potential, several leading countries are investing heavily in associated R&D. Approaches to Graphene research range from an expansive R&D focus (e.g., U.S. and the EU) to more focused approaches aimed at enhancing specific downstream applications with Graphene (e.g., South Korea). Faced with the need to push forward a multitude of development priorities, Malaysia must be targeted in its efforts to capture Graphene’s potential, both in terms of “how to compete” and “where to compete”. This National Graphene Action Plan 2020 lays out a set of priority applications that will be beneficial to the country as a whole and what the government will do to support these efforts.

Globally, much of the Graphene-related commercial innovation to date has been upstream, with producers developing techniques to manufacture Graphene at scale. There has also been some development in downstream sectors, as companies like Samsung, Bayer MaterialScience, BASF and Siemens explore product enhancement with Graphene in lithium-ion battery anodes and flexible displays, and specialty plastic and rubber composites. However the speed of development has been uneven, offering Malaysian industries willing to invest in innovation an opportunity to capture the value at stake. Since any innovation action plan has to be tailored to the needs and ambitions of local industry, Malaysia will focus its Graphene action plan initially on larger domestic industries (e.g., rubber) and areas already being targeted by the government for innovation such as energy storage for electric vehicles and conductive inks.

In addition to benefiting from the physical properties of Graphene, Malaysian downstream application providers may also capture the benefits of a modest input cost advantage for the domestic production of Graphene.  One commonly used Graphene manufacturing technique, the chemical vapour deposition (CVD) production method, requires methane as an input, which can be sourced economically from local biomass. While Graphene is available commercially from various producers around the world, downstream players may be able to enjoy some cost advantage from local Graphene supply. In addition, co-locating with a local producer for joint product development has the added benefit of speeding up the R&D lifecycle.

That business about finding downstream applications could also to the Canadian situation where we typically offer our resources (upstream) but don’t have an active downstream business focus. For example, we have graphite mines in Ontario and Québec which supply graphite flakes for graphene production which is all upstream. Less well developed are any plans for Canadian downstream applications.

Finally, it was interesting to note that the Phantoms Foundation is organizing this Malaysian conference since the same organization is organizing the ‘2nd edition of Graphene & 2D Materials Canada 2016 International Conference & Exhibition’ (you can find out more about the Oct. 18 – 20, 2016 event in my Sept. 23, 2016 posting). I think the Malaysians have a better title for their conference, far less unwieldy.

Testing technology for a global quantum network

This work on quantum networks comes from a joint Singapore/UK research project, from a June 2, 2016 news item on ScienceDaily,

You can’t sign up for the quantum internet just yet, but researchers have reported a major experimental milestone towards building a global quantum network — and it’s happening in space.

With a network that carries information in the quantum properties of single particles, you can create secure keys for secret messaging and potentially connect powerful quantum computers in the future. But scientists think you will need equipment in space to get global reach.

Researchers from the National University of Singapore (NUS) and the University of Strathclyde, UK, have become the first to test in orbit technology for satellite-based quantum network nodes.

They have put a compact device carrying components used in quantum communication and computing into orbit. And it works: the team report first data in a paper published 31 May 2016 in the journal Physical Review Applied.

A June 2, 2016 National University of Singapore press release, which originated the news item, provides more detail,

The team’s device, dubbed SPEQS, creates and measures pairs of light particles, called photons. Results from space show that SPEQS is making pairs of photons with correlated properties – an indicator of performance.

Team-leader Alexander Ling, an Assistant Professor at the Centre for Quantum Technologies (CQT) at NUS said, “This is the first time anyone has tested this kind of quantum technology in space.”

The team had to be inventive to redesign a delicate, table-top quantum setup to be small and robust enough to fly inside a nanosatellite only the size of a shoebox. The whole satellite weighs just 1.65-kilogramme.

Towards entanglement

Making correlated photons is a precursor to creating entangled photons. Described by Einstein as “spooky action at a distance”, entanglement is a connection between quantum particles that lends security to communication and power to computing.

Professor Artur Ekert, Director of CQT, invented the idea of using entangled particles for cryptography. He said, “Alex and his team are taking entanglement, literally, to a new level. Their experiments will pave the road to secure quantum communication and distributed quantum computation on a global scale. I am happy to see that Singapore is one of the world leaders in this area.”

Local quantum networks already exist [emphasis mine]. The problem Ling’s team aims to solve is a distance limit. Losses limit quantum signals sent through air at ground level or optical fibre to a few hundred kilometers – but we might ultimately use entangled photons beamed from satellites to connect points on opposite sides of the planet. Although photons from satellites still have to travel through the atmosphere, going top-to-bottom is roughly equivalent to going only 10 kilometres at ground level.

The group’s first device is a technology pathfinder. It takes photons from a BluRay laser and splits them into two, then measures the pair’s properties, all on board the satellite. To do this it contains a laser diode, crystals, mirrors and photon detectors carefully aligned inside an aluminum block. This sits on top of a 10 centimetres by 10 centimetres printed circuit board packed with control electronics.

Through a series of pre-launch tests – and one unfortunate incident – the team became more confident that their design could survive a rocket launch and space conditions. The team had a device in the October 2014 Orbital-3 rocket which exploded on the launch pad. The satellite containing that first device was later found on a beach intact and still in working order.

Future plans

Even with the success of the more recent mission, a global network is still a few milestones away. The team’s roadmap calls for a series of launches, with the next space-bound SPEQS slated to produce entangled photons. SPEQS stands for Small Photon-Entangling Quantum System.

With later satellites, the researchers will try sending entangled photons to Earth and to other satellites. The team are working with standard “CubeSat” nanosatellites, which can get relatively cheap rides into space as rocket ballast. Ultimately, completing a global network would mean having a fleet of satellites in orbit and an array of ground stations.

In the meantime, quantum satellites could also carry out fundamental experiments – for example, testing entanglement over distances bigger than Earth-bound scientists can manage. “We are reaching the limits of how precisely we can test quantum theory on Earth,” said co-author Dr Daniel Oi at the University of Strathclyde.

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

Generation and Analysis of Correlated Pairs of Photons aboard a Nanosatellite by Zhongkan Tang, Rakhitha Chandrasekara, Yue Chuan Tan, Cliff Cheng, Luo Sha, Goh Cher Hiang, Daniel K. L. Oi, and Alexander Ling. Phys. Rev. Applied 5, 054022 DOI: http://dx.doi.org/10.1103/PhysRevApplied.5.054022 Published 31 May 2016

This paper is behind a paywall.

Observing nanoparticle therapeutics interact with blood in real time

Sadly, there are no images showing nanoparticle therapeutics interacting with blood or anything else for that matter to illustrate this story but perhaps the insights offered should suffice. From Sept. 15, 2015 news item on Nanowerk,

Researchers at the National University of Singapore (NUS) have developed a technique to observe, in real time, how individual blood components interact and modify advanced nanoparticle therapeutics. The method, developed by an interdisciplinary team consisting clinician-scientist Assistant Professor Chester Lee Drum of the Department of Medicine at the NUS Yong Loo Lin School of Medicine, Professor T. Venky Venkatesan, Director of NUS Nanoscience and Nanotechnology Institute, and Assistant Professor James Kah of the Department of Biomedical Engineering at the NUS Faculty of Engineering, helps guide the design of future nanoparticles to interact in concert with human blood components, thus avoiding unwanted side effects.

A Sept. 15, 2015 NUS press release, which originated the news item, describes the research in more specific detail,

With their small size and multiple functionalities, nanoparticles have attracted intense attention as both diagnostic and drug delivery systems. However, within minutes of being delivered into the bloodstream, nanoparticles are covered with a shell of serum proteins, also known as a protein ‘corona’.

“The binding of serum proteins can profoundly change the behaviour of nanoparticles, at times leading to rapid clearance by the body and a diminished clinical outcome,” said Asst Prof Kah.

Existing methods such as mass spectroscopy and diffusional radius estimation, although useful for studying important nanoparticle parameters, are unable to provide detailed, real-time binding kinetics.

Novel method to understand nano-bio interactions

The NUS team, together with external collaborator Professor Bo Liedberg from the Nanyang Technological University, showed highly reproducible kinetics for the binding between gold nanoparticles and the four most common serum proteins: human serum albumin, fibrinogen, apolipoprotein A-1, and polyclonal IgG.

“What was remarkable about this project was the initiative taken by Abhijeet Patra, my graduate student from NUS Graduate School for Integrative Sciences and Engineering, in conceptualising the problem, and bringing together the various teams in NUS and beyond to make this a successful programme,” said Prof Venkatesan. “The key development is the use of a new technique using surface plasmon resonance (SPR) technology to measure the protein corona formed when common proteins in the bloodstream bind to nanoparticles,” he added.

The researchers first immobilised the gold nanoparticles to the surface of a SPR sensor chip with a linker molecule. The chip was specially modified with an alginate polymer layer which both provided a negative charge and active sites for ligand immobilisation, and prevented non-specific binding. Using a 6 x 6 microfluidic channel array, they studied up to 36 nanoparticle-protein interactions in a single experiment, running test samples alongside experimental controls.

“Reproducibility and reliability have been a bottleneck in the studies of protein coronas,” said Mr Abhijeet Patra. “The quality and reliability of the data depends most importantly upon the design of good control experiments. Our multiplexed SPR setup was therefore key to ensuring the reliability of our data.”

Testing different concentrations of each of the four proteins, the team found that apolipoprotein A-1 had the highest binding affinity for the gold nanoparticle surface, with an association constant almost 100 times that of the lowest affinity protein, polyclonal IgG.

“Our results show that the rate of association, rather than dissociation, is the main determinant of binding with the tested blood components,” said Asst Prof Drum.

The multiplex SPR system was also used to study the effect of modification with polyethylene (PEG), a synthetic polymer commonly used in nanoparticle formulations to prevent protein accumulation. The researchers found that shorter PEG chains (2-10 kilodaltons) are about three to four times more effective than longer PEG chains (20-30 kilodaltons) at preventing corona formation.

“The modular nature of our protocol allows us to study any nanoparticle which can be chemically tethered to the sensing surface,” explained Asst Prof Drum. “Using our technique, we can quickly evaluate a series of nanoparticle-based drug formulations before conducting in vivo studies, thereby resulting in savings in time and money and a reduction of in vivo testing,” he added.

The researchers plan to use the technology to quantitatively study protein corona formation for a variety of nanoparticle formulations, and rationally design nanomedicines for applications in cardiovascular diseases and cancer.

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

Component-Specific Analysis of Plasma Protein Corona Formation on Gold Nanoparticles Using Multiplexed Surface Plasmon Resonance by Abhijeet Patra, Tao Ding, Gokce Engudar, Yi Wang, Michal Marcin Dykas, Bo Liedberg, James Chen Yong Kah, Thirumalai Venkatesan, and Chester Lee Drum. Small  DOI: 10.1002/smll.201501603 Article first published online: 10 SEP 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

A bio-inspired robotic sock from Singapore’s National University

Should you ever be confined to a bed over a long period of time or find yourself unable to move your legs at will, this robotic sock could help you avoid blood clots according to a Feb. 10, 2015 National University of Singapore news release (also on EurekAlert but dated Feb. 13, 2015),

Patients who are bedridden or unable to move their legs are often at risk of developing Deep Vein Thrombosis (DVT), a potentially life-threatening condition caused by blood clots forming along the lower extremity veins of the legs. A team of researchers from the National University of Singapore’s (NUS) Yong Loo Lin School of Medicine and Faculty of Engineering has invented a novel sock that can help prevent DVT and improve survival rates of patients.

Equipped with soft actuators that mimic the tentacle movements of corals, the robotic sock emulates natural lower leg muscle contractions in the wearer’s leg, thereby promoting blood circulation throughout the wearer’s body. In addition, the novel device can potentially optimise therapy sessions and enable the patient’s lower leg movements to be monitored to improve therapy outcomes.

The invention is created by Assistant Professor Lim Jeong Hoon from the NUS Department of Medicine, as well as Assistant Professor Raye Yeow Chen Hua and first-year PhD candidate Mr Low Fanzhe of the NUS Department of Biomedical Engineering.

The news release goes on to contrast this new technique with the pharmacological and other methods currently in use,

Current approaches to prevent DVT include pharmacological methods which involve using anti-coagulation drugs to prevent blood from clotting, and mechanical methods that involve the use of compressive stimulations to assist blood flow.

While pharmacological methods are competent in preventing DVT, there is a primary detrimental side effect – there is higher risk of excessive bleeding which can lead to death, especially for patients who suffered hemorrhagic stroke. On the other hand, current mechanical methods such as the use of compression stockings have not demonstrated significant reduction in DVT risk.

In the course of exploring an effective solution that can prevent DVT, Asst Prof Lim, who is a rehabilitation clinician, was inspired by the natural role of the human ankle muscles in facilitating venous blood flow back to the heart. He worked with Asst Prof Yeow and Mr Low to derive a method that can perform this function for patients who are bedridden or unable to move their legs.

The team turned to nature for inspiration to develop a device that is akin to human ankle movements. They found similarities in the elegant structural design of the coral tentacle, which can extend to grab food and contract to bring the food closer for consumption, and invented soft actuators that mimic this “push and pull” mechanism.

By integrating the actuators with a sock and the use of a programmable pneumatic pump-valve control system, the invention is able to create the desired robot-assisted ankle joint motions to facilitate blood flow in the leg.

Explaining the choice of materials, Mr Low said, “We chose to use only soft components and actuators to increase patient comfort during use, hence minimising the risk of injury from excessive mechanical forces. Compression stockings are currently used in the hospital wards, so it makes sense to use a similar sock-based approach to provide comfort and minimise bulk on the ankle and foot.”

The sock complements conventional ankle therapy exercises that therapists perform on patients, thereby optimising therapy time and productivity. In addition, the sock can be worn for prolonged durations to provide robot-assisted therapy, on top of the therapist-assisted sessions. The sock is also embedded with sensors to track the ankle joint angle, allowing the patient’s ankle motion to be monitored for better treatment.

Said Asst Prof Yeow, “Given its compact size, modular design and ease of use, the soft robotic sock can be adopted in hospital wards and rehabilitation centres for on-bed applications to prevent DVT among stroke patients or even at home for bedridden patients. By reducing the risk of DVT using this device, we hope to improve survival rates of these patients.”

The team does not seem to have published any papers about this work although there are plans for clinical trials and commercialization (from the news release),

To further investigate the effectiveness of the robotic sock, Asst Prof Lim, Asst Prof Yeow and Mr Low will be conducting pilot clinical trials with about 30 patients at the National University Hospital over six months, starting March 2015. They hope that the pilot clinical trials will help them to obtain patient and clinical feedback to further improve the design and capabilities of the device.

The team intends to conduct trials across different local hospitals for better evaluation, and they also hope to commercialise the device in future.

The researchers have provided an image of the sock on a ‘patient’,

 Caption: NUS researchers (from right to left) Assistant Professor Raye Yeow, Mr Low Fanzhe and Dr Liu Yuchun demonstrating the novel bio-inspired robotic sock. Credit: National University of Singapore


Caption: NUS researchers (from right to left) Assistant Professor Raye Yeow, Mr Low Fanzhe and Dr Liu Yuchun demonstrating the novel bio-inspired robotic sock.
Credit: National University of Singapore