PhD Mechanical Engineering student Fahad Nawar Al-Otaibi received the Outstanding Paper Award at the 1^st World Conference on Multiphase Transportation, Conversion & Utilization of Energy (MTCUE) 2022. The hybrid conference is a platform for industry experts, academics, and students to discuss the challenges, as well as new research, in multiphase flow, including the basic phenomena and theory, the modeling and mathematical methods, the interface reaction and process, etc.

The Outstanding Paper Award is given to participating researchers whose paper has the best overall contribution to the subject discipline. The conference received 314 papers, and Fahad’s paper, “Numerical Study of Dry Reforming of Methane in Fixed & Fluidized Beds,” received the accolade under the Organic Waste Conversion and Utilization category.

Under the supervision of Dr. Abdallah S. Berrouk, Associate Professor, Mechanical Engineering and Dr. Kyriaki Polychronopoulou, Professor, Mechanical Engineering, Fahad has developed optimized CFD models that unlock the full capacity of dry reformation of methane from its challenging designs and potentially replace the steam reformation of methane processes known for emitting serious concerning amounts of greenhouse gases.

Fahad’s paper is part of the continuing research efforts of the Center of Catalysis and Separation (CeCaS)��to enhance the efficiency of petrochemical processes and reduce their carbon footprint.

Ara Maj Cruz
Features Writer
6 September 2022

The post Fahad Nawar Al-Otaibi Wins Outstanding Paper Award at the MTCUE 2022 Conference appeared first on Khalifa University.

A novel filtration device has the potential to filter wastewater much more efficiently and in an environmentally-safe manner, using 3D printing to manufacture structures based on fish gills.��

Their device is chemical-free and uses a 3D printing-on-membrane approach to develop a single device that mimics the shape and high surface area of fish gills at the microscale.

Prof. TieJun Zhang, Professor of Mechanical Engineering; Dr. Hongxia Li, Postdoctoral Research Fellow; Dr. Aikifa Raza, Research Scientist; and Dr. Faisal AlMarzooqi, Assistant Professor of Chemical Engineering; with Shaojun Yuan, Sichuan University; and Nicholas Fang, MIT, published their results in.

Membrane filtration is a widely used technique with applications from the biomedical industry to environmental sciences. At its simplest, the water-filtration process sees purified water permeate through the membrane, while contaminants such as microplastics, oil droplets, and other soluble pollutants are stopped by the membrane. Some contaminants would accumulate on membrane surface, or get trapped in membrane. This trapping is the major bottleneck in effective water filtration, as, over time, the membrane becomes clogged with the separated particles.

Most solutions to overcome membrane clogging focus on developing novel materials or modifying the surface of the membrane, using metal oxides and photocatalytic materials to repel contaminants and prevent the membrane from degrading. However, such chemical approaches may be easy to implement and effective, but environmental concerns have been raised around their use in nature.

Many fish species feed by filtering food particles from huge volumes of water without clogging their oral filters. Their mouths contain structures called gill rakers, which work much in the same way that a spaghetti strainer or coffee filter functions: Water is forced through the pores of the filter, trapping the desired particles.

“Surface patterning and creating topological structures on membrane surfaces can manipulate the local hydrodynamics and prevent clogging on the membrane,” Prof. Zhang said. “With properly designed surface structures, the flow of water near the membrane surface can be controlled to inhibit the deposition of particles that would clog the membrane. For this, surface geometry is the key.”

Different surface structures like grooves and pyramids have demonstrated anti-fouling properties. Fish gills present these structures but they are remarkably complex, and replicating them is made possible only with emerging 3D printing techniques. Recent advances in micro-stereolithography 3D printing have made it possible to fabricate complex structures at the microscale, but it is still challenging to fabricate these surface architectures and membranes with nanometer pores at one-step, and usually, the nanoporous membrane has to be manufactured separately. With the new direct-printing on membrane technique used by the research team, the filtration membrane and complex surface structures can be integrated as an all-in-one device, making it the first of its kind for filtration purposes. A patent has been filed for this technique, towards its commercialization.

Gill raker-shaped structures were printed directly onto the membrane surface, with the final device integrating all the functional components of a filter.

“We developed a microfluidic filtration device,” Dr. Li said. “When we tested it against oily water and wastewater with microplastics, we found that the extraordinary anti-fouling performance of a fish gill-structured membrane originates from the unique flow behavior of the oil droplet and plastic microparticle during the filtration process. As the water containing the droplet/particle approaches one of the gill structures, the forces acting on the water cause the droplet/particle to ‘ricochet’ away, and thus avoid oil droplets or microplastics contaminating the membrane surface. In this way, even though the droplet/particle size is much smaller than the gap between two neighboring gill structures, it cannot pass through the gap and remains in the main flow of water. This means that only clean water passes through the membrane and the filtration device does not become clogged with contaminates.”

The potential application fields of printing on membrane are myriad and diverse, with membranes in microfluidics one of the most important. Integrated with the enormous variety of materials, morphologies, and design options, the ”print-and-play” microfluidic membrane devices can be readily tailored to other emerging energy, chemistry, bioengineering, and medical applications.��

Jade Sterling
Science Writer
19 July 2022

The post How Fish Gills Inspired Clog-Free Filters to Tackle Ocean Pollution appeared first on Khalifa University.

طور فريق من الباحثين في جامعة خليفة جهازًا جديدًا يمكن ارتداؤه بإمكانه مساعدة المصابين بعمى الألوان. While using dyes to develop lenses for glasses to help correct colorblindness is not new, the team has developed a method using 3D printing to manufacture customized glasses.��

Dr. Haider Butt, Associate Professor of Mechanical Engineering, Dr. Fahad Alam, Postdoctoral Fellow, Dr. Mohamed Elsherif, Postdoctoral Fellow, and Ahmed Salih, all Department of Mechanical Engineering, published their results in This research also inspired a Senior Design Project for undergraduate students Saif Abdulla Alnaqbi, Ali Saif Rashid Alshawi Aleghfeli, Rashid Ali Khalfan Bin Gahfan Al Ali, and Mohammad Ali Mohamad Hussain Ali Alshamali.

A transparent resin was used to make the lenses, mixed with two wavelength-filtering dyes to provide a tinting effect. The researchers used three different concentrations of the dyes to customize the lenses and compared their 3D-printed glasses to commercially available products used to treat color vision deficiency (CVD).

“Patient-specific customization of glasses for CVD remains a challenge, even though research has significantly advanced the properties and materials of CVD wearables available on the market,” Dr. Butt said.

The retina of the eye has three types of cones: One perceives blue light, another green, and the third red. These cones work together to allow people to see the whole spectrum of colors, but CVD is an inherited ocular disorder that limits this ability. Red-green color blindness is the most prevalent form of CVD, with most sufferers relying on wearables to manage the difficulties in day-to-day tasks. The most common wearable is a form of tinted glass.

Deuteranomaly, which occurs mostly in men, is a condition in which the photoreceptor responsible for detecting green light responds to light associated with red. This can be improved using red-tinted glasses, which make the colors more prominent. Certain dyes can absorb and filter out some of the wavelengths between green and red that confuse the photoreceptors. With less color overlap, the brain gets a clearer signal to help distinguish between the problem colors. This concept can also be extended to the other forms of CVD.

The KU team used two dyes: One blocked the undesired wavelengths for red-green patients, while the other filtered unwanted wavelengths for yellow-blue patients. The team used both dyes in their lenses, and when tested, volunteers with red-green CVD and yellow-blue CVD both benefited from the glasses, suggesting their efficacy at managing both CVD types.

Glasses based on this approach are commercially and readily available, but they are bulky and can be uncomfortable. The KU research team developed their own frames for their lenses, using 3D printing to optimize the frames for comfort and usability. Inspired by commercially available designs, their 3D printed glasses can fold like other glasses, making them more usable to the wearer.

The stability of the dyes within the 3D printed glasses was examined by storing the glasses in water over a week. Their results showed that no dye leaked into the water, indicating their stability. They also left the glasses open at ambient conditions for a further week, proving their stability and long-lasting properties.

Their mechanical properties were also carefully assessed. Their flexibility and tensile strength are crucial components in quantifying their longevity and durability, and when tested, the glasses exhibited excellent durability, without breaking even when subjected to folding or bending.

“Our results showed that 3D printing had no influence on the wavelength-filtering properties of the dyes,” Dr. Butt said. “In fact, the dyes remained unchanged as they were integrated with the resin and 3D printed. When we compared the optical performance of our glasses with commercial colorblind glasses, our results indicated that our 3D-printed glasses were more selective in filtering undesired wavelengths than the commercially available options. They have great potential in treating colorblindness, and their ease of fabrication and customization means they can be tailored to each individual patient.”

The research work was funded by Sandooq Al Watan and Aldar Properties.

Jade Sterling
Science Writer
30 June 2022

The post تطوير نظارات مصنوعة باستخدام تقنية الطباعة ثلاثية الأبعاد لعلاج عمى الألوان appeared first on Khalifa University.

3D printing makes manufacturing regular lenses, and more recently Fresnel lenses, easy and cost-efficient, but now, additive manufacturing can be used to extend their functionality with enhanced optical properties and sensing abilities.����

Dr. Haider Butt, Associate Professor, Murad Ali, Ph.D. candidate, and Dr. Fahad Alam, Postdoctoral Fellow, all Department of Mechanical Engineering, published their results in.

In optical designs, spherical and aspherical lenses form and guide light. Aspherical lenses have a more complex surface profile, making them difficult to manufacture, but a single aspheric lens can often replace a much more complex multi-lens system.

Fresnel lenses concentrate light using a stepped surface that bends the light as much as a thick, heavy glass lens. They are made of concentric rings, and each ring bends the light slightly more than the one below it, so all the light rays emerge in perfect, parallel beams.��

“Fresnel lenses are innovative spherical lenses characterized by optimized mass and materials,” Dr. Butt said. “While they originated in lighthouses, they are now used in field lenses, magnifiers, smartphones, photovoltaic panels, ultrasonic devices, and miniature spectrometers, among many other uses.”

Fresnel lenses in lighthouses are used to create powerful beams of light that stretch long distances. Unlike the conventional lenses in a telescope, for example, the optical quality of the light beam emerging from a lighthouse lens doesn’t matter. This means the Fresnel lens can be made from plastic, such as acrylic or polycarbonate, as well as glass, making their manufacture cheaper and easier.

“Acrylic exhibits excellent optical characteristics for multiple applications in solar technology, for example, especially in concentrating photovoltaic systems,” Dr. Butt said. “Alternative silicon Fresnel lenses are also used in space applications such as solar concentrators with glass protection. These are easily produced by casting, injection molding, and compression molding.”

However, if the Fresnel lens is to be used to collect light from a distance and bring it into a sharply focused image, precision manufacturing is key. Inexpensively made Fresnel lenses make poorer quality images than traditional glass lenses due to spherical aberration: Light rays travelling through a Fresnel lens at different angles will come to a focus at slightly different points, creating a blurred image. Because the surface of the lens is discontinuous, the image is distorted, and because different colors are refracted by the lens to different degrees, chromatic aberration is also a concern.

Adjusting the angle of the steps in a Fresnel lens is crucial to minimizing aberrations, although current manufacturing techniques limit design and processing flexibility.

“High resolution printers have made it possible to print 3D micro- and nano-optical components to perform complex optical operations,” Dr. Butt said. “For instance, optical waveguides and lenses are immensely popular as light-guiding devices, using complex geometric shapes integrated with optical fibers, gas, and optofluidic sensors. Advances in additive manufacturing are pushing optical and photonic devices into new and unexplored architectures with immense commercialization potential.”

In this research, the lens was designed with 15 rings of a constant width of just 0.833mm.

��“3D printing processes are more promising to explore the design strategies and complexity of Fresnel lenses,” Dr. Butt said. “3D printing also allows for multimaterials-based lens production, for sensing and multifunctional optics.

Thermochromic materials undergo a coloration or discoloration process at specific temperatures: When the temperature reaches a particular value, a color change occurs. To add thermal sensing to the lenses and make them four-dimensional, a thermochromic pigment powder was added as a responsive material to the transparent hydrogel resin that constitutes the Fresnel lens itself. This powder causes a reversible change, turning the lens from transparent to pink when temperatures drop. Various concentrations of the pigment can be used for parameter-specific optical applications, making the manufacturing process tunable to different applications.

The fifth dimension was introduced by embedding microscale holographic patterns on one side of the lenses. A variety of textured surfaces with holographic effects can be embedded into 3D parts, with the holographic film applied to the print bed of the 3D printer. A microsize holographic pattern in a Fresnel lens enables the lens to focus light and simultaneously exhibit the holographic effect. And the holographic effect is more than just aesthetically pleasing: The rainbow pattern generated could easily be combined with an image sensor, providing a miniature spectrometer for mechanoluminescence-sensing applications.

“Although the lenses we made have suitable optical properties, further improvements are always possible,” Dr. Butt said. “Reducing the thickness of each layer could improve optical performance, and a different curing technique could make the surface of the lens smoother. Regardless, we have shown that additive manufacturing can fabricate optical components with promising applications in the fields of sensing and communication.”

Jade Sterling
Science Writer
22 June 2022

The post Color-Changing, Holographic Fresnel Lenses Made Possible with Additive Manufacturing appeared first on Khalifa University.

Pressure sensors are used in electronic devices across all industries and making them as accurate as possible means making them as thin as possible. Researchers from Khalifa University have developed a method to use a novel 2D material for highly-sensitive and tunable flexible pressure sensors.��

Compared with conventional rigid silicon-based electronics, thin, flexible electronics can withstand various deformations such as tension, compression, bending and twisting. Pressure sensors that can transform external pressure into electrical signals are an indispensable application of flexible electronics, particularly for biomedical applications.

A team of researchers from Khalifa University has investigated how to develop a pressure sensor using a novel 2-Dimensional (2D) material, which is a single sheet of material that is just one atom thick, and 3D printing. They published their results in The research team includes Jing Fu, Research Associate, Somayya Taher, PhD candidate, Prof. Rashid Abu Al-Rub, Director of the Advanced Digital and Additive Manufacturing Group and Professor of Mechanical Engineering, Prof. TJ Zhang, Professor of Mechanical Engineering, Prof. Vincent Chan, Professor of Biomedical Engineering, and Prof. Kin Liao, Professor of Aerospace Engineering.

“Pressure sensors can be divided into various categories, including piezoelectric pressure sensors and piezoresistive pressure sensors,” Dr. Kin explained. “The working principle of a piezoresistive pressure sensor capitalizes on the change in the electrical resistance of the sensor against applied pressure. Such sensors have a simple structure, high sensitivity, fast-frequency response and low-energy consumption, making them popular candidates for various applications.”

An effective pressure sensor needs to be sufficiently thin. A sensor that is too thick may give erroneous readings as the sensor would press into a soft material, decreasing the load between the objects and increasing the measured pressure. To be as accurate as possible, researchers have turned to 2D materials to achieve sensors that are thin as possible.

“The engineering performance and robustness of a piezoresistive sensor mainly hinge on the sensor’s embedded active material,” Dr. Kin explained. “So far, different kinds of conductive materials have been used, such as metal nanoparticles, conductive polymers, graphene, and transition metal compounds. More recently, 2D materials have captured researchers’ attention worldwide, particularly transition metal carbides and nitrides or MXenes.”

MXenes are a family of 2D materials comprised of a pretransition metal, such as titanium (Ti), zirconium (Zr) or hafnium (Hf), with carbon and/or nitrogen, and hydroxyl, oxygen or fluorine surface functional group. These combinations give MXenes excellent electrical conductivity and hydrophilicity, making them promising candidates for applications such as piezoresistive sensors.��

As a 2D material, MXenes can be used as sheets and stacked on top of each other via van der Waals forces or hydrogen bonding between the functional groups. This way, MXenes can be formed into flexible and stable films, although the resulting material shows a very weak piezoresistive effect because when compressed, the structure of the sheet doesn’t allow for much deformation. Using MXenes in a 3D structure with similar length scales in all three dimensions would overcome this issue and make best use of the novel MXene material.

The Khalifa University team used additive manufacturing to develop the 3D structures. Traditional methods use templates upon which MXene layers are deposited before the templates are removed. While this does work, it does not allow for precise control of the internal structure of the resulting 3D scaffold. 3D printing overcomes this, with the technology able to fabricate flexible pressure-sensitive sensors with a high dynamic range through an easy to manipulate and large-scale manufacturing method.

“There are enormous possibilities in the design of internal structures that could be produced by 3D printing, but the triply periodic minimal surface (TPMS) structure is one of the more interesting,” Dr. Kin said. “The TPMS structure is known for possessing characteristics of surface area, mechanical robustness and thermal conductivity with an edge-free structure. Fabrication of 2D MXenes into the periodic, porous TPMS structure will lead to the development of novel 3D scaffolds with excellent electrical conductivity and mechanical properties.”

The team developed a simple and efficient method to combine MXene with a uniquely designed TPMS gyroid structure to create a 3D MXene-based gyroidal structure for use as a piezoresistive sensor with extremely high sensitivity, good response time and improvable durability. This method can be used to fabricate 3D MXene structures with any size, shape and internal structure.

More recently, Prof. Liao’s group has been working on constructing 3D structures of heterogenous 2D materials – different types of 2D materials organized in layered manner – for applications such as sensors, electromagnetic interference shielding, as well as energy-related applications.

Jade Sterling
Science Writer
25 May 2022

The post Advances in Flexible Pressure Sensors Using 3D Printing and 2D Materials appeared first on Khalifa University.

Further advances in rechargeable batteries are essential to meet the demand for electric vehicles and energy storage. A novel two-dimensional (2D) material may be the solution to mitigating the so-called ‘shuttle effect’ in lithium-sulfur battery technology.��

As renewable energy production technologies improve and shrink, and electric vehicles become more popular, the demand for portable energy storage is increasing.

Currently, lithium-ion batteries are the standard, but energy density and cost must continually improve to achieve the levels of deployment needed for the most ambitious sustainability targets. Alkali metal-sulfur batteries, a type of lithium-ion battery, have emerged as a promising option, especially in applications requiring high energy storage capacity. However, one issue with metal-sulfur batteries is the so-called ‘shuttle effect’: metal particles called polysulphides dissolve into the battery’s electrolyte and are transported from the sulfur cathode to the metal anode. This reduces capacity and charging performance of the battery.

Finding a way to suppress the shuttle effect is crucial to metal-sulfur battery performance and lifetime. Khalifa University’s Hiba Al-Jayyousi, Master’s student, Department of Mechanical Engineering, Dr. Nirpendra Singh, and Dr. Muhammad Sajjad, both Department of Physics, and Prof. Kin Liao, Department of Aerospace Engineering investigated the use of 2D biphenylene sheet as a material to ‘anchor’ the metal particles and prevent them from shuttling. Their results were published in.

“Over the last three decades, lithium-ion rechargeable batteries have gained vast popularity due to their low self-discharge, ample energy storage, stable cycling performance, higher theoretical capacity and specific energy density, which directly affects the development of energy storage technologies,” Dr. Singh said. “Li-ion batteries are environmentally-friendly and suitable for portable electronics, as they offer much higher energy density than other rechargeable systems.”

Although lithium sulfur batteries have high theoretical capacity and energy density, the shuttle effect seriously hinders this technology’s development. The research team found that trapping lithium polysulfides on a biphenylene sheet effectively suppresses the shuttle effect and enhances the cycling stability of Li-S batteries. The biphenylene is a newly synthesized two-dimensional material, where the carbon atoms are arranged in a square, hexagonal, and octagonal rings. Compared with other reported two-dimensional materials such as graphene and phosphorene, the biphenylene sheet used by the research team exhibited higher binding energies with the polysulfides.

A suitable anchoring material should have excellent conductivity, high surface area, porous structure, and high binding energy with the polysulfides to prevent them from dissolving into electrolytes. Several 2D materials have been proposed and investigated, including and nonpolar polyaniline previously investigated by Dr. Singh.

“Our study shows that the biphenylene sheet is an excellent anchoring material for lithium-sulfur batteries for suppressing the shuttle effect because of its superior conductivity, porosity, and strong anchoring ability,” Al-Jayyousi said.

As energy consumption continues to rise, finding new materials that can make renewable energy generation and storage cleaner and more efficient will be key to meeting the world’s growing energy demands sustainably.��

Jade Sterling
Science Writer
20 May 2022

The post A Promising Anchoring Material for Lithium-sulfur Batteries appeared first on Khalifa University.

Seramic Materials applies patented technology to upcycle industrial solid waste to sustainable and high-value ceramic products, driving the industry towards a near-zero waste goal

Started by Dr. Nicolas Calvet, Khalifa University Assistant Professor of Mechanical Engineering and CEO of Seramic Materials, and Dr. Khalid Al Ali, Khalifa University Assistant Professor of Chemical Engineering and Director of Operations at Seramic Materials, Seramic Materials Ltd. was established in 2019 to manufacture 100 percent recycled ceramic products from heavy industry waste, such as incinerator ash and byproducts from the steel industry.

“Seramic Materials is a UAE-based company born out of the unique and innovative environment of the Masdar Institute at Khalifa University,” Dr. Calvet said. “We developed a unique circular economy solution to recycling solid industrial waste into sustainable value-added products in the technical ceramics and construction materials markets.”

Replacing a precious natural resource with waste products for ceramic production has myriad advantages beyond keeping the conventional raw materials in the ground. Using waste products can be significantly cheaper, meaning a final product can be 10 to 50 percent cheaper depending on its application.

By avoiding the extraction of natural resources and their transport, carbon emissions are significantly reduced and manufacturing energy consumption is also lowered. Dr. Calvet says this represents at least a 20 percent reduction in carbon dioxide emissions compared with conventional ceramic manufacturing methods. Plus, all the waste that would have headed to landfill can now be diverted to a second life and purpose.

. Seramic Materials can combine the UAE’s steel slag, municipal solid waste incinerator ashes, bauxite residue, waste sludge, broken glass and more with non-depleting natural resources, such as desert sand, to develop their ceramic products.

“We tune the properties of the final ceramic product depending on its expected use by mixing different waste products together,” Dr. Calvet said. “Our ceramic materials can be shaped in any form and dimension depending on their intended applications, such as bricks, floor and wall tiles, 3D claddings, pavers, and much more.

Seramic Materials is now expanding into technical ceramics, manufacturing advanced thermal energy storage materials, which can operate in temperatures as high as 1250°C, and which are, to date, the most cost-efficient ceramics on the market.

Thermal energy storage involves storing heat, generated for instance by solar energy, until it is needed to be turned into electricity or reused directly as process heat. It is the release of the heat that is used to generate the power.

“Our solution is called ReThink Seramic – Flora and it is a game changer in high-temperature applications – anything over 700°C,” Dr. Calvet said. “Until now, the bottleneck in this industry was the high cost of the ceramic material itself. By operating at a higher temperature, the heat-to-electricity conversion efficiency is improved, and since Flora is durable up to 1250°C, it can be thermally cycled over decades without damage.”

“We have developed the first state-of-the-art laboratory in the GCC dedicated to industrial solid waste valorization” said Dr. Khalid Al Ali.�� Thanks to this one-of-its-kind laboratory, the team at Seramic Materials have developed formulations that are patented in Europe, USA, India, China and the GCC and are constantly working on new applications to support products across the ceramics value chain.�� Seramic Materials recently signed an intellectual property (IP) agreement with Khalifa University to commercialize 5 patents related to steel slags upcycling.

“Our vision is a more sustainable present achieved by developing a circular economy,” Dr. Calvet said. “We have an innovative approach that we hope will continuously enhance our ceramic formulations and offer countless new value-added applications for our commercial products.”

Jade Sterling
Science Writer
18 October 2021

The post KU Start-Up Pioneers in Upcycling Waste for Circular-Economy Ceramics appeared first on Khalifa University.

Khalifa University Team Also Retains 6^th Spot in Design Segment to Remain Ahead of Renowned International Universities

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Khalifa University has announced that a 21-member student team led by Sultan Al Hassanieh has won the top spot in verbal presentation for the first time during the Knowledge Event at the 42^nd Society of Automotive Engineers (SAE) Collegiate Design Series Supermileage Competition for 2021. The team also retained 6^th spot overall in the Design Event, the same position it won last year in Michigan, US.

The verbal design report demonstrates the Khalifa University team’s understanding and application of the engineering principles that support their design of the one-person, single-cylinder engine vehicle, capable of achieving fantastic fuel economy during a 6-lap attempt around an approximately 1.6-mile-long, banked, oval track.

Since the traditional validation event at the 42nd SAE Collegiate Design Series Supermileage Competition was cancelled due to the pandemic this year, the organizers opted to score teams based on two major criteria – the submitted design report that details the design and fabrication of the vehicle, and a verbal presentation on Zoom in which team members present their design process and final outcome to a panel of judges. The student team was then critically questioned, and the Khalifa University students proved their mettle to reach the top spot. They were also assessed on team participation, program knowledge and technical knowledge.

Dr. Arif Sultan Al Hammadi, Executive Vice-President, Khalifa University, said: “Our faculty members and the students have once again demonstrated that Khalifa University remains the top-ranked, globally-acknowledged academic institution with unparalleled expertise. Winning an international competition of this stature not only brings honor to the university but also to the UAE. Congratulations to the student team and the faculty members who guided them through training and support.”

The Khalifa University team achieved this remarkable feat even though it entirely consisted of only first-time participants, demonstrating the world-class faculty’s role in imparting knowledge, as well as the talented students’ capability in designing and presenting the project to the international judges. Also for the first time, this year’s team comprised students from all majors.

Dr. Bashar Khasawneh, Associate Professor, Mechanical Engineering, and Dr. Reyad El-Khazali, Associate Professor, Electrical and Computer Engineering, advised the students on the project.

In line with the healthcare protocols being implemented on campus at Khalifa University, team members were allowed to visit the campus and work on fabricating parts of the vehicle that they are responsible for, while complying with all necessary safety precautions. Team members used online video communications applications to ensure safety while discussing the general concept of the design, which was then developed into working theoretical models of the vehicle’s subsystems.

Dr. Khasawneh said: “Though the student team leaders were initially worried that the majority of the work would be held online, they achieved the top position because of team skills. What made the Khalifa University Supermileage team one of the best in the world was how every member ensured to constantly support and motivate each other, creating an inherently supportive atmosphere.”

The SAE Collegiate Design Series Supermileage Competition challenges students to design and construct a single-person, fuel efficient vehicle that will run a specified course to obtain the highest combined km/L (mpg) rating. Teams generally spend 8-12 months designing, building, and preparing their vehicles for competition.

Clarence Michael
English Editor Specialist
5 July 2021

The post Khalifa University Student Team Wins Top Spot in Verbal Presentation at 2021 SAE Collegiate Design Series Supermileage Competition appeared first on Khalifa University.

Khalifa University researchers found a way to optimize capillary action – a process that moves liquid passively – in thin-film evaporators, which are used to generate steam and purify water with solar energy, cool buildings and electronics, and much more.��

Evaporation is a process fundamental to everyday life. It keeps our bodies cool and the air moist, and it plays a critical role in a number of industrial systems that drive our society today, from providing power and purifying water, to cooling buildings and electronics.�� Thin-film evaporation is an extremely effective and energy-efficient way to transfer heat. For thin-film evaporation to work, however, a stable liquid film needs to be maintained on the surface, which can be a challenge.��

Inspired by the same process used by plants to carry water up from their roots to their leaves, capillary-fed wicks offer an attractive means of moving liquid to the surface since it is a passive mechanism; it does not rely on an external power supply or a mechanical pump to deliver the fluid to the evaporator.

Researchers and engineers are continuously exploring ways to improve the performance of passive liquid propagation, solar energy-driven evaporation and water distillation. “Using wicks to supply liquid to the evaporating surface via a process called capillarity may be the solution to providing a constant, stable liquid film for thin-film evaporation,” explained Dr. Tiejun Zhang, Associate Professor of Mechanical Engineering. With funding support from a 2019 Abu Dhabi Award for Research Excellence (AARE), Dr. Zhang is leading a research team from Khalifa University to investigate how to improve wickability, or how efficiently liquid travels up through a wick, and in turn, the performance of thin-film evaporation. They recently published their work in the journal.��

Co-authors include Dr. Hongxia Li, Postdoctoral Fellow, Afra Al Ketbi and Qiangshun Guan, Graduate Students, and Dr. Mohamed Alhosani and Ablimit Aili, PhD and MSc Graduates, all from the Department of Mechanical Engineering.

Wicking is the absorption of a liquid by a porous material, with the liquid then transferred through the process of evaporation. Daily examples of capillary action can be seen when dipping a paintbrush in water where the liquid is drawn up between the brush hairs against gravity, or in a paper towel dipped in spilled coffee as the liquid moves up the pores of the paper. Rather than an external energy supply causing capillary action, intermolecular forces cause the surface tension of the liquid and the adhesive forces between the liquid and solid to propel the liquid through the solid material. This is how the tallest trees can pull water through the roots to the highest branches.

The crucial role of capillary pumping for thin-film evaporators has motivated KU researchers to explore ways to improve wickability.����

Many factors, like surface wettability and permeability, affect a material’s ability to propagate, or spread of liquid and can significantly reduce the rate at which the liquid is absorbed in the wick. Viscous pressure drop, surface roughness, blockages, and twists and turns can all slow the movement of the liquid through the material.

Wickability can be enhanced by improving the intrinsic wettability of the wick surfaces to stop it from drying out during evaporation, and through designing a porous structure to maximize fluid flow.

Dr. Zhang’s team developed a wick with excellent capillary pumping ability by creating nanostructures made of copper onto a water-loving, hydrophilic surface, also made of copper. This created a large, porous surface area for thin-film evaporation. As an additional benefit, in solar-driven applications where the wicking porous material also acts as a solar absorber, these nano-structures can also help harvest the sunlight more efficiently.

The KU team then used their prototype to create a model to predict how effective a material’s wickability would be based on a number of different factors, including pore sizes, shapes and orientations. The model can help researchers design effective wicks in the future.

“We systematically characterized the water propagation dynamics from microscale to macroscale through experimental observation and theoretical modelling,” explained Dr. Li. “We fabricated a nanostructured porous wicking surface—essentially a copper micromesh attached to a flat copper substrate with a nanostructured surface. The micromesh improves wickability by acting as the wicking structure, providing capillary pressure with relatively high permeability, while the copper oxide nanostructures enhance the surface hydrophilicity.”

The team then observed the water propagation behaviors under optical and infrared thermal cameras to develop a capillary pressure model and permeability model to predict how efficiently the capillary-pumped water travelled along the porous surfaces. They also conducted studies with varying pore sizes before optimizing pore dimension to achieve the maximum capillary pumping rate.

The KU team’s technology offers outstanding solar-driven evaporation capability owing to their high liquid propagation rate and excellent light absorption. The proposed scalable nanostructured porous surfaces promise great potential in broad energy and sustainability applications.

Jade Sterling
Science Writer
9 June 2021

The post Harnessing Capillary Action and Solar Energy to Improve Evaporation and Produce Clean Water appeared first on Khalifa University.

Dr. Daniel Choi, Associate Professor of Mechanical Engineering, was one of the invited speakers at the Innovation@UAE Majlis Research Talk Series on 29 March 2021. Organized by the Ministry of Education, this webinar focused on space-related research.

Along with Dr. Choi, the other speakers at the event were Nour Abu Raad, Researcher at the Mohammed bin Rashid Centre for Space Research at the University of Dubai, and Aisha Al Owais, Research Assistant at the Sharjah Academy for Space, Astronomy, Science, and Technology at the University of Sharjah. The session was moderated by Dr. Hend Al Tair, Director of Department of Science, Technology and Scientific Research, Ministry of Education.

During his talk, Dr. Choi introduced the ‘Wonder’ Flexible Battery, a thin battery intended primarily for space and aerospace applications but can also be used in wearable applications. Dr. Choi and his team were able to produce a battery that weighs less than 20 percent of the weight of a traditional battery.�� “You would expect a large trade-off in energy density, but for the same volume of a traditional battery, ours offers approximately 90 percent the same energy density,” Dr. Choi said.

“Another advantage of our ‘flexible’ battery for space applications is that the flexibility of the nanocomposite material means it can be shaped to fit any odd or underutilized space inside and outside of the spacecraft instead of requiring a dedicated space to be built in, which can reduce the total weight of the spacecraft,” Dr. Choi explained.

After each presentation, attendees were given an opportunity to ask questions, opening an engaging discussion on current and future space research in the UAE. This series of webinars are part of the Ministry’s mission of advancing and supporting academic research in the country by giving a platform to academic researchers leading innovative projects of relevance to the UAE. The interactions between academic researchers and the public increase science engagement and contribute to scientific literacy and public participation in science.

��Ara Maj Cruz
Creative Writer
15 April 2021

The post Dr. Daniel Choi Talks about the ‘Wonder’ Battery at the Innovation@UAE Majlis appeared first on Khalifa University.

Using red-tinted glasses can make colors more prominent, but achieving this correction in a comfortable manner is more challenging.

A collaborative team of researchers from Khalifa University and Imperial College London has developed a new contact lens that could help people with color blindness. Rather than the conventional approach, using dyes to tint lenses, the research team uses gold nanoparticles to filter red and green light, creating a safer way to see colors.

The research team includes Dr. Haider Butt, Associate Professor of Mechanical Engineering, Dr. Mohamed Elsherif, Postdoctoral Fellow, Dr. Fahad Alam, Postdoctoral Fellow, and recent MSc graduate, all from Khalifa University, along with Dr. Alil Yetisen, Associate Professor of Chemical Engineering at Imperial College London. They published their work last month in.

Problems with distinguishing red from green restrict people from working in fields where color recognition is critical, but can also have everyday ramifications as simple as deciding whether a banana is ripe or selecting matching clothes.

The retina of the eye has three types of cones: one perceives blue light, another green, and the third red. These cones work together to allow people to see the whole spectrum of colors, except when one doesn’t work properly.

“Color vision deficiency (CVD), more commonly known as color blindness, is an inherited ocular disorder that limits the sufferer’s ability to distinguish between specific colors,” explained Dr. Butt. “Red-green color blindness is the most prevalent form of CVD, with most sufferers relying on wearables to manage the difficulties in day-to-day tasks. The most common wearable is a form of tinted glass.”

Deuteranomaly, which occurs mostly in men, is a condition in which the photoreceptor responsible for detecting green light responds to light associated with red. This can be improved using red-tinted glasses, which make the colors more prominent, but achieving this correction in a comfortable manner is more challenging. Glasses based on this approach are commercially and readily available, but they are bulky and can be uncomfortable. Contact lenses do exist, but their reported effectiveness varies among tested patients and the stability of the dyes within the contact lenses is insufficient for daily use.��

“Research on CVD management techniques has shown that dyed contact lenses are expensive and have leaching and toxicity problems,” explained Dr. Butt. “We used gold nanoparticles instead. Noble metal nanoparticles, particularly gold and silver, have excellent electrical and optical properties, making them suitable for various biomedical applications, while they also display excellent light absorption and scattering properties.”

Conventional color-correcting lenses are made with certain minerals to absorb and filter out some of the wavelengths between green and red that confuse the photoreceptors. With less color overlap, the brain gets a clearer signal to help distinguish between the problem colors, but this does reduce the amount of light getting into the eye.

Gold, on the other hand, has been used for hundreds of years in cranberry glass, where red glass is made by adding gold salts to molten glass. Gold nanocomposites are non-toxic and scatter light in such a way as to create this red glass look. The researchers believed this scattering quality could be leveraged and incorporated into contact lens material to improve the red-green contrast safely and effectively.

Dr. Butt and colleagues put their theory to test and designed a contact lens with embedded gold nanoparticles that successfully filtered out the range of optical wavelengths at which CVD patients have difficulty distinguishing between specific colors.

The gold nanoparticles were embedded into a hydrogel polymer, which was shaped into the contact lenses, producing rose-tinted gels that filtered the light where red and green overlap. Importantly, the lenses were also studied for the effect of the nanoparticles on the water content and hydration for the eyes. The researchers found that the gold did not have an appreciable effect on the water content of the gel, meaning it can be used in contact lens applications without any undesirable side effects.

When compared with commercially available glasses and dyed lenses, the team’s lenses were just as effective, with comparable water content.

Now, the team aims to investigate the oxygen permeability of the hydrogel used in their lenses, before they can be deployed and help people with CVD to see the world differently.��

The research is jointly funded by Sandooq Al Watan, Aldar Properties, and Khalifa University.

Jade Sterling
Science Writer
5 April 2021

The post Through Rose-tinted Contact Lenses: Gold Nanocomposites Help the Color-Blind See the World Differently appeared first on Khalifa University.

The team’s ‘solar crystallizer’ uses solar energy as the main energy source to heat and evaporate the brine

Read Arabic story .

Brine is a high-concentration solution of salt in water and is a by-product of many industrial processes, including desalination. The simplest way to dispose of brine is to return it to the ocean, but high localized brine concentrations raise seawater salinity and alkalinity to the point that an environmental risk is created.

Another common way to dispose of brine is to use evaporation ponds, where the water is evaporated and the salt is collected for use in other processes.

Unfortunately, neither method is a fully environmentally-friendly approach, and untreated brine can be corrosive and toxic if disposed of improperly.����

A team of researchers, including Khalifa University’s Dr. Tiejun Zhang and Dr. Hongxia Li from the Department of Mechanical Engineering, has designed a new, sustainable way to treat brine without disposing of any water, using the energy from the sun.

Dr. Zhang and Dr. Li published their work in with Chenlin Zhang and Prof. Peng Wang’s group from King Abdullah University of Science and Technology, Saudi Arabia.

The collaborative research team led by Prof. Wang designed a ‘solar crystallizer’ that uses solar energy as the main energy source to heat and evaporate the brine.

“Proper disposal of industrial brine is a critical environmental challenge,” explained Dr. Zhang. “The volumes of brine produced by modern industries range from hundreds of liters to tens of thousands of liters. Conventional methods of disposing brine are detrimental to aquatic ecosystems and land vegetation systems. Concentrating the brine to near saturation and then evaporating the water in a contained system can remove all residual water from the brine to produce solid salts in a zero liquid discharge process.”

Typically, a zero liquid discharge process concentrates the original source brine to near saturation and uses a process known as ‘crystallization’ to remove all the salts from the solution. Brine crystallizers are sometimes used to separate the salt from the water, but they require electricity to heat the brine for water evaporation, resulting in high energy consumption.

“Solar-driven water evaporation is gaining popularity as an environmentally friendly way to produce water vapor for clean water production via solar distillation,” explained Dr. Zhang. “In such a process, solar energy is harvested and converted to heat using a photothermal material, producing water vapor from various source waters in a solar still. Then, the condensate from the water vapor is collected as fresh water.”

Sounds simple, but the amount of salt in the water can affect the light absorption of the photothermal materials, water transport and evaporation in wicking materials.

To solve this, the research team designed a new 3D solar crystallizer device in which the water evaporation surface and the light absorption surface are physically separated by an aluminum sheet with high thermal conductivity. The bottom and inner walls act as the sunlight absorbing component, absorbing 99 percent of the light that hits it, while the outer wall surface serves as the water evaporation surface and salt crystallization surface.

“The high thermal conductivity of the aluminum separator conducts the heat generated at the bottom of the device to its wall for water evaporation,” explained Dr. Li.

“This results in a high solar-to-vapor performance, meaning this simple but promising strategy can provide a low-cost and sustainable solution, especially for small to medium-sized industrial brine treatment.”

Dr. Zhang has teamed up with Dr. Faisal Al Marzooqi to develop more advanced solutions at Khalifa University for sustainable solar brine treatment with anti-fouling, anti-corrosion and anti-scaling performance.

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Jade Sterling
Science Writer
31 March 2021

The post Harnessing the Power of the Sun to Desalinate Brine Sustainably appeared first on Khalifa University.