Tag Archives: Erica Solomon

Memristors at Masdar

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The Masdar Institute of Science and Technology (Abu Dhabi, United Arab Emirates; Masdar Institute Wikipedia entry) featured its work with memristors in an Oct. 1, 2017 Masdar Institute press release by Erica Solomon (for anyone who’s interested, I have a simple description of memristors and links to more posts about them after the press release),

Researchers Develop New Memristor Prototype Capable of Performing Complex Operations at High-Speed and Low Power, Could Lead to Advancements in Internet of Things, Portable Healthcare Sensing and other Embedded Technologies

Computer circuits in development at the Khalifa University of Science and Technology could make future computers much more compact, efficient and powerful thanks to advancements being made in memory technologies that combine processing and memory storage functions into one densely packed “memristor.”

Enabling faster, smaller and ultra-low-power computers with memristors could have a big impact on embedded technologies, which enable Internet of Things (IoT), artificial intelligence, and portable healthcare sensing systems, says Dr. Baker Mohammad, Associate Professor of Electrical and Computer Engineering. Dr. Mohammad co-authored a book on memristor technologies, which has just been released by Springer, a leading global scientific publisher of books and journals, with Class of 2017 PhD graduate Heba Abunahla. The book, titled Memristor Technology: Synthesis and Modeling for Sensing and Security Applications, provides readers with a single-source guide to fabricate, characterize and model memristor devices for sensing applications.

The pair also contributed to a paper on memristor research that was published in IEEE Transactions on Circuits and Systems I: Regular Papers earlier this month with Class of 2017 MSc graduate Muath Abu Lebdeh and Dr. Mahmoud Al-Qutayri, Professor of Electrical and Computer Engineering.PhD student Yasmin Halawani is also an active member of Dr. Mohammad’s research team.

Conventional computers rely on energy and time-consuming processes to move information back and forth between the computer central processing unit (CPU) and the memory, which are separately located. A memristor, which is an electrical resistor that remembers how much current flows through it, can bridge the gap between computation and storage. Instead of fetching data from the memory and sending that data to the CPU where it is then processed, memristors have the potential to store and process data simultaneously.

“Memristors allow computers to perform many operations at the same time without having to move data around, thereby reducing latency, energy requirements, costs and chip size,” Dr. Mohammad explained. “We are focused on extending the logic gate design of the current memristor architecture with one that leads to even greater reduction of latency, energy dissipation and size.”

Logic gates control an electronics logical operation on one or more binary inputs and typically produce a single binary output. That is why they are at the heart of what makes a computer work, allowing a CPU to carry out a given set of instructions, which are received as electrical signals, using one or a combination of the seven basic logical operations: AND, OR, NOT, XOR, XNOR, NAND and NOR.

The team’s latest work is aimed at advancing a memristor’s ability to perform a complex logic operation, known as the XNOR (Exclusive NOR) logic gate function, which is the most complex logic gate operation among the seven basic logic gates types.

Designing memristive logic gates is difficult, as they require that each electrical input and output be in the form of electrical resistance rather than electrical voltage.

“However, we were able to successfully design an XNOR logic gate prototype with a novel structure, by layering bipolar and unipolar memristor types in a novel heterogeneous structure, which led to a reduction in latency and energy consumption for a memristive XNOR logic circuit gate by 50% compared to state-of the art state full logic proposed by leading research institutes,” Dr. Mohammad revealed.

The team’s current work builds on five years of research in the field of memristors, which is expected to reach a market value of US$384 million by 2025, according to a recent report from Research and Markets. Up to now, the team has fabricated and characterized several memristor prototypes, assessing how different design structures influence efficiency and inform potential applications. Some innovative memristor technology applications the team discovered include machine vision, radiation sensing and diabetes detection. Two patents have already been issued by the US Patents and Trademark Office (USPTO) for novel memristor designs invented by the team, with two additional patents pending.

Their robust research efforts have also led to the publication of several papers on the technology in high impact journals, including The Journal of Physical Chemistry, Materials Chemistry and Physics, and IEEE TCAS. This strong technology base paved the way for undergraduate senior students Reem Aldahmani, Amani Alshkeili, and Reem Jassem Jaffar to build novel and efficient memristive sensing prototypes.

The memristor research is also set to get an additional boost thanks to the new University merger, which Dr. Mohammad believes could help expedite the team’s research and development efforts through convenient and continuous access to the wider range of specialized facilities and tools the new university has on offer.

The team’s prototype memristors are now in the laboratory prototype stage, and Dr. Mohammad plans to initiate discussions for internal partnership opportunities with the Khalifa University Robotics Institute, followed by external collaboration with leading semiconductor companies such as Abu Dhabi-owned GlobalFoundries, to accelerate the transfer of his team’s technology to the market.

With initial positive findings and the promise of further development through the University’s enhanced portfolio of research facilities, this project is a perfect demonstration of how the Khalifa University of Science and Technology is pushing the envelope of electronics and semiconductor technologies to help transform Abu Dhabi into a high-tech hub for research and entrepreneurship.

h/t Oct. 4, 2017 Nanowerk news item

Slightly restating it from the press release, a memristor is a nanoscale electrical component which mimics neural plasticity. Memristor combines the word ‘memory’ with ‘resistor’.

For those who’d like a little more, there are three components: capacitors, inductors, and resistors which make up an electrical circuit. The resistor is the circuit element which represents the resistance to the flow of electric current.  As for how this relates to the memristor (from the Memristor Wikipedia entry; Note: Links have been removed),

The memristor’s electrical resistance is not constant but depends on the history of current that had previously flowed through the device, i.e., its present resistance depends on how much electric charge has flowed in what direction through it in the past; the device remembers its history — the so-called non-volatility property.[2] When the electric power supply is turned off, the memristor remembers its most recent resistance until it is turned on again

The memristor could lead to more energy-saving devices but much of the current (pun noted) interest lies in its similarity to neural plasticity and its potential application on neuromorphic engineering (brainlike computing).

Here’s a sampling of some of the more recent memristor postings on this blog:

August 24, 2017: Neuristors and brainlike computing

June 28, 2017: Dr. Wei Lu and bio-inspired ‘memristor’ chips

May 2, 2017: Predicting how a memristor functions

December 30, 2016: Changing synaptic connectivity with a memristor

December 5, 2016: The memristor as computing device

November 1, 2016: The memristor as the ‘missing link’ in bioelectronic medicine?

You can find more by using ‘memristor’ as the search term in the blog search function or on the search engine of your choice.

Masdar Institute and rainmaking

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Water security, of course, is a key issue and of particular concern in many parts of the world including the Middle East. (In the Pacific Northwest, an area described as a temperate rain forest, there tends to be less awareness but even we are sometimes forced to ration water.) According to a July 5, 2017 posting by Bhok Thompson (on the Green Prophet website) scientists at the Masdar Institute of Science and Technology (in Abu Dhabi, United Arab Emirates [UA]E) have applied for a patent on a new technique for rainmaking,

Umbrella sales in the UAE may soon see a surge in pricing. Researchers at the Masdar Institute have filed for a provisional patent with the United States Patent and Trademark Office for their discovery – and innovative cloud seeding material that moves them closer to their goal of producing rain on demand. It appears to be a more practical approach than building artificial mountains.

Dr. Linda Zou is leading the project. A professor of chemical and environmental engineering, she is one of the first scientists to explore nanotechnology to enhance a cloud seeding material’s ability to produce rain. By filing a patent, the team is paving a way to commercialize their discovery, and aligning with Masdar Institute’s aim to position the UAE as a world leader in science and tech, specifically in the realm of environmental sustainability.

A January 31, 2017 posting by Erica Solomon for the Masdar Institute reveals more about the project,

The Masdar Institute research team that was one of the inaugural recipients of the US$ 5 million grant from the UAE Research Program for Rain Enhancement Science last year has made significant progress in their work as evidenced by the filing a provisional patent with the United States Patent and Trademark Office (USPTO).

By filing a patent on their innovative cloud seeding material, the research team is bringing the material in the pathway for commercialization, thereby supporting Masdar Institute’s goal of bolstering the United Arab Emirates’ local intellectual property, which is a key measure of the country’s innovation drive. It also signifies a milestone towards achieving greater water security in the UAE, as rainfall enhancement via cloud seeding can potentially increase rainfall between 10% to 30%, helping to refresh groundwater reserves, boost agricultural production, and reduce the country’s heavy reliance on freshwater produced by energy-intensive seawater desalination.

Masdar Institute Professor of Chemical and Environmental Engineering, Dr. Linda Zou, is the principal investigator of this research project, and one of the first scientists in the world to explore the use of nanotechnology to enhance a cloud seeding material’s ability to produce rain.
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“Using nanotechnology to accelerate water droplet formation on a typical cloud seeding material has never been researched before. It is a new approach that could revolutionize the development of cloud seeding materials and make them significantly more efficient and effective,” Dr. Zou remarked.

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Conventional cloud seeding materials are small particles such as pure salt crystals, dry ice and silver iodide. These tiny particles, which are a few microns (one-thousandth of a millimeter) in size, act as the core around which water condenses in the clouds, stimulating water droplet growth. Once the air in the cloud reaches a certain level of saturation, it can no longer hold in that moisture, and rain falls. Cloud seeding essentially mimics what naturally occurs in clouds, but enhances the process by adding particles that can stimulate and accelerate the condensation process.

Dr. Zou and her collaborators, Dr. Mustapha Jouiad, Principal Research Scientist in Mechanical and Materials Engineering Department, postdoctoral researcher Dr. Nabil El Hadri and PhD student Haoran Liang, explored ways to improve the process of condensation on a pure salt crystal by layering it with a thin coating of titanium dioxide.

The extremely thin coating measures around 50 nanometers, which is more than one thousand times thinner than a human hair. Despite the coating’s miniscule size, the titanium dioxide’s effect on the salt’s condensation efficiency is significant. Titanium dioxide is a hydrophilic photocatalyst, which means that when in contact with water vapor in the cloud, it helps to initiate and sustain the water vapor adsorption and condensation on the nanoparticle’s surface. This important property of the cloud seeding material speeds up the formation of large water droplets for rainfall.

Dr. Zou’s team found that the titanium dioxide coating improved the salt’s ability to adsorb and condense water vapor over 100 times compared to a pure salt crystal. Such an increase in condensation efficiency could improve a cloud’s ability to produce more precipitation, making rain enhancement operations more efficient and effective. The research will now move to the next stage of simulated cloud and field testing in the future.

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Dr. Zou’s research grant covers two more years of research. During this time, her team will continue to study different design concepts and structures for cloud seeding materials inspired by nanotechnology.

To give you a sense of the urgent need for these technologies, here’s the title from my Aug. 24, 2015 posting, The Gaza is running out of water by 2016 if the United Nations predictions are correct. I’ve not come across any updates on the situation in the Gaza Strip but both Israel and Palestine have recently signed a deal concerning water. Dalia Hatuqa’s August 2017 feature on the water deal for Al Jazeera is critical primarily of Israel (as might be expected) but there are one or two subtle criticisms of Palestine too,

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Critics have also warned that the plan does not address Israeli restrictions on Palestinian access to water and the development of infrastructure needed to address the water crisis in the occupied West Bank.

Palestinians in the West Bank consume only 70 litres of water per capita per day, well below what the World Health Organization recommends as a minimum (100).

In the most vulnerable communities in Area C – those not connected to the water network – that number further drops to 20, according to EWASH, a coalition of Palestinian and international organisations working on water and sanitation in the Palestinian territories.

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The recent bilateral agreement, which does not increase the Palestinians’ quota of water in the Jordan River, makes an untenable situation permanent and guarantees Israel a lion’s share of its water, thus reinforcing the status quo, Buttu [Diana Buttu, a former adviser to the Palestinian negotiating team] said.

“They have moved away from the idea that water is a shared resource and instead adopted the approach that Israel controls and allocates water to Palestinians,” she added. “Israel has been selling water to Palestinians for a long time, but this is enshrining it even further by saying that this is the way to alleviate the water problem.”

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Israeli officials say that water problems in the territories could have been addressed had the Palestinians attended the meetings of the joint committee. Palestinians attribute their refusal to conditions set by their counterparts, namely that they must support Israeli settlement water projects for any Palestinian water improvements to be approved.

According to Israeli foreign ministry spokesman Emmanuel Nahshon, “There are many things to be done together to upgrade the water infrastructure in the PA. We are talking about old, leaking pipes, and a more rational use of water.” He also pointed to the illegal tapping into pipes, which he maintained Palestinians did because they did not want to pay for water. “This is something we’ve been wanting to do over the years, and the new water agreement is one of the ways to deal with that. The new agreement … is not only about water quotas; it’s also about more coherent and better use of water, in order to address the needs of the Palestinians.”

But water specialists say that the root cause of the problem is not illegal activity, but the unavailability of water resources to Palestinians and the mismanagement and diversion of the Jordan River.

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Access to water is gong to be of increasing urgency should temperatures continue to rise as they have. In many parts of the world, potable water is not easy to find and if temperatures continue to rise areas that did have some water security will lose it and the potential for conflict rises hugely. Palestine and Israel may be a harbinger of what’s to come. As for the commodification of water, I have trouble accepting it; I think everyone has a right to water.

Next generation of power lines could be carbon nanotube-coated

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This research was done at the Masdar Institute in Abu Dhabi of the United Arab Emirates. From a Sept. 1, 2016 news item on Nanowerk,

A Masdar Institute Assistant Professor may have brought engineers one step closer to developing the type of next-generation power lines needed to achieve sustainable and resilient electrical power grids.

Dr. Kumar Shanmugam, Assistant Professor of Materials and Mechanical Engineering, helped develop a novel coating made from carbon nanotubes that, when layered around an aluminum-conductor composite core (ACCC) transmission line, reduces the line’s operating temperature and significantly improves its overall transmission efficiency.

An Aug. 29, 2016 Masdar Institute news release by Erica Solomon, which originated the news item, provides more detail,

The coating is made from carbon nanostructures (CNS) – which are bundles of aligned carbon nanotubes that have exceptional mechanical and electrical properties – provided by the project’s sponsor, Lockheed Martin. The second component of the coating is an epoxy resin, which is the thick material used to protect things like appliances and electronics from damage.  Together, the CNS and epoxy resin help prevent power lines from overheating, increases their current carrying capacity (the amount of current that can flow through a transmission line), while also protecting them from damages associated with lightning strikes, ice and other environmental impacts.

The researchers found that by replacing traditional steel-core transmission lines with ACCC cables layered with a CNS-epoxy coating (referred to in the study as ACCC-CNS lines), the amount of aluminum used in an ACCC cable can be reduced by 25%, making the cable significantly lighter and cheaper to produce. The span length of a transmission line can also increase by 30%, which will make it easier to transmit electricity across longer distances while the amount of current the line can carry can increase by 40%.

“The coating helps to dissipate the heat generated in the conductor more efficiently through radiation and convection, thereby preventing the cable from overheating and enabling it to carry more current farther distances,” Dr. Kumar explained.

Ultimately, the purpose of the coating is to effectively eliminate the transmission line losses. Each year, anywhere from 5% to over 10% of the overall power generated in a power plant is lost in transmission and distribution lines. Most of this electrical energy is lost in the form of heat; as current runs through a conductor (the transmission line), the conductor heats up because it resists the flow of electrons to some extent – a phenomenon known as resistive Joule heating. Resistive Joule heating causes the energy that was moving the electrons forward to change into heat energy, which means some of the generated power gets converted into heat and lost to the surrounding environment instead of getting to its intended destination (like our homes and offices).

In addition to wasting energy, resistive Joule heating can lead to overheating, which can trigger a transmission line to “sag”, or physically droop low to the ground. Sagging power lines in turn can have catastrophic effects, including short circuits and power outages.

Efforts to reduce the problem of resistive heating and energy loss in power lines have led to significant improvements in transmission line technologies. For example, in 2002 ACCC transmission cables – which feature a carbon and glass-fiber reinforced composite core wrapped in aluminum conductor wires – were invented. The ACCC conductors are lighter and more heat-resistant than traditional steel-core cables, which means they can carry more current without overheating or sagging. Today, it is estimated that over 200 power and distribution networks use ACCC transmission cables.

While the advent of composite core cables marks the first major turning point in the development of energy-efficient transmission lines, Dr. Kumar’s CNS-epoxy coating may be the second significant advancement in the evolution of sustainable power lines.

The CNS-epoxy coating works by keeping the cable’s operating temperatures low. It does this by dissipating, any generated heat away from the conductor efficiently, thereby preventing further increase in temperature of the line and avoiding the trickle-effect that often leads to overheating.

The coating is layered twice in the ACCC cable – an outer layer, which dissipates the heat and protects the cable from environmental factors like lightning strikes and foreign object impact; and an inner layer, which protects the composite core from damage caused by stray radio frequency radiation generated by the electromagnetic pulse emanating from high electric current carrying aluminum conductor

The research team utilized a multi-physics modeling framework to analyze how the CNS-epoxy coating would influence the performance of ACCC transmission line. After fabricating the coating, they characterized it, which is a critical step to determine its mechanical, thermal and electrical properties. These properties were then used in the computational and theoretical models to evaluate and predict the coating’s performance. Finally, a design tool was developed and used to find the optimal combination of parameters (core diameter, span distance and sag) needed to reduce the cable’s weight, sag, and operating temperature while increasing its span distance and current carrying capacity.

Dr. Kumar’s innovative transmission line technology research comes at a pivotal time, when countries all over the world, including the UAE, are seeking ways to reduce their carbon footprint in a concerted effort to mitigate global climate change. Turning to energy-efficient power lines that waste less power and in turn produce less carbon dioxide emissions will be an obvious choice for nations devoted to greater sustainability.

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

High-Ampacity Overhead Power Lines With Carbon Nanostructure–Epoxy Composites by V. S. N. Ranjith Kumar, S. Kumar, G. Pal, and Tushar Shah. J. Eng. Mater. Technol 138(4), 041018 (Aug 09, 2016) (9 pages) Paper No: MATS-15-1217; doi: 10.1115/1.4034095

This paper is behind a paywall.