Month: March 2023

Twenty-nine-year-old Daniella Bar-Lev was drawn to mathematics in high school where she studied in a class for gifted teens, while at the same time taking courses at the Open University. “In these courses, I was exposed to mathematics beyond the calculus that you study in high school, and I realized that this is the field I would like to pursue,” Daniela explained. “When I enrolled at the Technion, the well-known warning that ‘you can’t do anything with a mathematics degree’ echoed in my head, so I enrolled in both mathematics and computer science, in order to get a taste of both fields and choose the one I liked best. I came to realize that I loved the connection between the two, and completed a double degree.”

Daniella was raised in Ashdod, where she continues to live today with her partner. Her parents immigrated from the Soviet Union in the 1970s. Her mother worked for many years in the finance department at the Wolfson Medical Center in Holon and her – father at the Ackerstein brick factory in Ashdod. “Neither of them is a computer person, the love for the field is something I developed on my own,” Daniella recalled.  The choice to pursue higher education wasn’t trivial either. “There are no universities in Ashdod, so academia doesn’t have a presence in one’s daily experience. Nonetheless, here I am, after my bachelor’s and master’s degrees and in the middle of my doctoral studies.”

She completed her bachelor’s degree with commendable honors as part of “LAPIDIM” – the Faculty of Computer Science’s excellence program, designed to train future leaders in the hi-tech industry. Towards the end of her degree, Daniella started working as a teaching assistant at the Henry and Marilyn Taub Faculty of Computer Science. Among other things, she tutored her younger sister, also a student at the faculty.

It was already clear to her then that she wanted to earn a master’s degree, but the search for an advisor was not bearing fruit.  Eventually, she began to look for advisors at other universities. However, a meeting with Prof. Shaul Markovitch, who was the faculty vice dean for undergraduate studies at the time, changed her course.

“He strongly suggested that I speak with Prof. Eitan Yaakobi from the computer science department before making any decisions. I met with Prof. Yaakobi, and he explained his research to me. Shortly after, we continued to a meeting with Prof. Tuvi Etzion, who was Eitan’s advisor for his master’s degree. It was love at first sight, both personally and academically, and I was thrilled when they agreed to be joint supervisors for my master’s degree. The very next day, I began working on my research proposal,” said Daniela.

Daniella’s graduate research, which later evolved into her doctoral thesis, delves into various aspects of DNA storage. This field, which has been developing rapidly in the last decade, explores the potential of using biological material, rather than traditional electronic devices, as a means of information storage. This approach offers several benefits, including the significant miniaturization of storage systems, long-term storage of information 1,000 times longer than in current solutions, and a substantial reduction in both energy and economic costs.

The DNA molecule is composed of four nucleotides, which are organic building blocks denoted by the letters A, C, G, and T. Unlike the binary language of zeros and ones used in current technologies, DNA storage relies on sequences of these four letters to encode information.

To write (that is, to store) the information with this technology, synthesis is required. This is the process of creating the DNA molecules that represent the sequence, and to read the information, sequencing of those molecules is required.

The process of reading information stored in DNA is a complex one, and writing it is even more so. During these processes, errors of various types can occur. These are the main focus of Daniella’s research. “Errors in DNA storage differ significantly from those in typical hardware, which impact the encoding and decoding process as well as the process of retrieving the stored information. This requires the use of mathematical tools, so familiarity with math is required here, a field that I very much enjoy and can contribute to,” Daniella explained.

She emphasizes another aspect that brings her satisfaction in her research work – the knowledge that it can have a significant impact. “When I started my master’s degree, it was considered a promising field. Today, it is already clear to me that this is a field that will change the future. Electronic storage is reaching its limits of capacity in all aspects – physical space, costs, energy, and the environmental impact – and a dramatic alternative is needed, not just minor improvements. I have no doubt that DNA storage is an excellent option, but more work is needed before it can become widely available. Unlike conventional memory, where we know the specific address that we need to access in the hardware, working with DNA is entirely different. It is like a ‘soup’ of molecules. Therefore, I hope that our contribution in the field of error correction will be apparent soon on the applied level as well.”

Her decision to pursue a Ph.D. after completing her master’s degree was solidified during the COVID-19 pandemic. “It was a time of remote work and introspection, and I discussed the idea with Eitan. The smile on his face confirmed that I was on the right track, and more importantly, that I’m good at what I do. This recognition is invaluable because we often struggle to accurately assess ourselves, especially during periods of isolation when we are working from home and spend most of our time alone.”

Daniella’s performance in her master’s thesis paved the way for her acceptance into a direct path towards a doctorate, which she now sees as just the beginning of her academic journey. “I have a passion for both research and teaching, and in my Ph.D. I work closely with graduate students. The academic world is one that I knew very little about until I arrived at the Technion, but it has become clear that this is where I belong. In addition to my academic work, it is also important to me to introduce children and teenagers to this world. I volunteer in elementary schools where I present what I do and what the academic track is like. Through this, I address the common fears among young girls and work to break down gender biases surrounding academia and higher education. I hope that my efforts have a significant impact.”

Throughout her academic journey, Daniella has received numerous scholarships and awards, including the Gutwirth Excellence Scholarship, Faculty Excellence Scholarship, Faculty Persistent Excellent Teaching Assistant Award, the Best Paper Award at a conference, and the Student Research Prize for Cross-PI Collaboration in Data Science. “Daniella is the best student I have ever had,” declares Prof. Yaakobi. “Not only does she help me supervise graduate students, but she also leads my research group while guiding and assisting many students. I’m certain she will become a faculty member and I hope it will be at the Technion.”

Researchers at the Technion – Israel Institute of Technology have developed devices that connect electronics with biology and are suitable for monitoring various ions in a solution, sensing in biological systems, and other applications.

The research was headed by doctoral student Eyal Stein and Professor Gitti Frey from the Technion’s Faculty of Materials Science and Engineering along with colleagues from the Wolfson Faculty of Chemical Engineering at the Technion, the University of Oxford in the U.K., and the King Abdullah University of Science and Technology in Saudi Arabia. The article was published in Nature Communications.

In this study, Technion scientists established a toolbox for creating organic electrochemical transistors (OECTs), which are used in a wide variety of applications including those that require adapting to bio-compatible tissue. These components translate ionic signals in an aqueous solution to electric signals, and as such they are particularly well suited for applications involving the interface between biology and electronics. “The device is based on the coupling of ions from a physiological solution with charges in the transistor’s semiconductor channel, and therefore the biological single, expressed by the ions, is translated and amplified into detectable electronic signals. This translation between biological and electric signals is vital for developing innovative medical devices,” explained Prof. Frey.

The novelty of the research lies in the creation of an ambipolar device – one that is able to translate both negative and positive ionic signals by blending two organic semiconductors that have opposite polarities (a polythiophene and a fullerene derivative). This combination ensures that the device has a great deal of versatility and enhanced capabilities compared to existing materials. The study showed that both components are active from an optical, electrochemical, and electric perspective, and at the same time do not disturb each other’s performance. The uniformity of the active layer and the electric stability are a result of the layer’s tailored structure and morphology at a nanometric level.

The new technology is likely to accelerate the development and creation of integrated circuits based on ambipolar OECTs for biological applications. The researchers predict this current achievement will pave the way for designing and creating a new generation of bioelectronics that will be compact, flexible, and simple to produce. This technology can be utilized, for example, for the immediate diagnosis of various physiological conditions, brain activity, and other uses based on changes in the body’s liquids and soft tissue.

For the full paper: https://www.nature.com/articles/s41467-022-33264-2

The research was supported by the European Union (Horizon 2020 grant)

An experimental achievement by researchers at the Technion – Israel Institute of Technology in the field of quantum condensation may accelerate research in quantum information processing and developments in security, biological sensing, wireless communication, and more. Published recently in Optica, the research was led by doctoral student Nadav Landau and Professor Alex Hayat from the Andrew and Erna Viterbi Faculty of Electrical and Computer Engineering at the Technion and conducted in collaboration with colleagues in Germany.

Quantum condensation is a physical phenomenon in which a large number of matter particles maintain coherence over time and space – a very important feature for many of the quantum technologies being developed today. Optically excited quantum condensation has been achieved so far only through one-photon absorption – a process in which one photon excites a matter particle to a higher energy state, where condensation then occurs.

Two-photon absorption, on the other hand, is a process where two photons are simultaneously absorbed to excite a matter particle, bringing about many scientific and technological advantages. Among other things, it is essential for long-term quantum memory applications. The states of matter that can be reached in such a process are characterized by very low emission of light, and in this context are thus called “dark states.”

To observe two-photon absorption leading to condensation, unique experimental conditions that have not been achieved so far due to complex technological and scientific challenges are necessary. Extremely high-power lasers and ultra-short pulses in time are needed to avoid heating. The Technion researchers overcame these challenges, and in the article they present quantum condensation from a two-photon absorption process in a semiconductor chip. This achievement paves the way for new, practically-realizable quantum technologies by coupling “dark states” to quantum condensates on a solid-state platform.

One of the promising applications of this breakthrough is the realization of very efficient laser sources in the terahertz (THz) range of electromagnetic radiation. Such sources are vital for many applications in fields such as biological sensing, security, materials science, and communication, but finding them has been a notoriously difficult challenge for many years due to fundamental physical reasons.

The result the researchers observed can, in principle, enable the achievement of orders-of-magnitude increased THz emission through a process of doubly stimulated emission.

The research was supported by the Israel Science Foundation (ISF).

To read the full paper, click here

 

In Israel, the sea almost literally flows into our taps. We Israelis pride ourselves on the achievements of our country in the field of desalination, with 5 desalination plants spread across the Israeli shores of the Mediterranean, which produce drinking water equivalent to about 75% of the national domestic water consumption, and more facilities to be built in the coming years.

A perfect solution for a desert country? Perhaps, yet everything comes at a cost: to make seawater or brackish water drinkable, the desalination plants in Israel consume a lot of electricity. A new invention, recently presented at the 5^th biannual student conference of the Stephen and Nancy Grand Water Research Institute (GWRI), tries to solve this energy problem, and might even create a revolution in the availability of desalinated water worldwide. This invention by the Technion researchers consists of a unique wind turbine that does not require any electricity for it to run, and is inexpensive and easy to use and maintain.

Enter the vertical axis wind turbine

The electric energy consumed today by desalination processes stands at about 3.5 kilowatt-hours (kWh) for each cubic meter of water. For the sake of illustration, approximately 4 percent of all electric energy produced in Israel in 2015 was used for desalination. In addition to the high environmental costs of such vast energy consumption – energy which is produced in Israel mainly by burning fossil fuels – the need for so much electricity keeps the technology of desalinating and purifying water beyond the reach of over a billion people around the world who have no access to clean drinking water.

At the core of the new invention lies a turbine not known by many – the vertical axis wind turbine (VAWT). This turbine rotates around an upright axis (to visualize the movement of the turbine blades, imagine a giant egg-beater), unlike the more familiar wind turbines, whose axis is horizontal. Despite the prevalence of horizontal axis turbines, highly efficient VAWT blade configurations have been developed in the Technion’s Flow Control Laboratory, headed by Professor David Greenblatt. “The tip of the blade of a ‘normal’ wind turbine spins about 7 times faster than the wind that moves it, while our blades spin at about the same speed as the wind – that is, up to 7 times slower than traditional wind turbines,” explains Dr. David Keisar of the Faculty of Mechanical Engineering at the Technion, who conducted the research – guided by Prof. Greenblatt – as part of his doctoral thesis in the Grand Technion Energy Program (GTEP). “Our vertical axis turbines operate well even at low wind speeds, and they are very efficient in producing energy, considering their size and rotational speed.” According to Keisar, the fact that the vertical axis turbines spin slowly makes them much quieter than the horizontal axis ones, as well as safer for birds – who can see their blades and don’t fly into them.

Keisar says that another benefit of using VAWTs is in the fact that the blades that spin are connected to a shaft spanning the whole height of the turbine – this way, any device that uses the rotational speed of the turbine – be it an electric generator or any other device – can be placed close to the ground, and not at the top of the turbine, as the horizontal axis turbines require. This fact simplifies their installation, as well as their regular operation and maintenance. Another important advantage of VAWTs is that they can spin no matter the direction of the wind blowing at them, as opposed to horizontal axis turbines which run optimally only when they face the direction of the wind (or against the wind, according to their design).

Turbines for small-scale systems

Mentioning all of these advantages begs the question: why don’t we always use vertical axis turbines instead of the well-known horizontal axis ones? “Horizontal axis turbines are still better at generating high-power electricity, and economically they are the most efficient ones at large scales,” explains Keisar. Additionally, he says, the axis and the bearings (parts that reduce friction while spinning) of VAWTs tend to fall apart and break faster than their horizontal axis counterparts.

“However, this problem rises mainly when the vertical axis turbines are large,” Keisar reassures. “When small, they work well and are far more robust.” Therefore, in small systems that are meant to be used in distant places by non-professionals, the advantages of vertical axis turbines – being able to run at a low-speed wind, no matter which direction it blows, as well as their ease of installation and maintenance – make them a better solution than the horizontal axis ones.

On the drawing board

The goal of the research headed by Prof. Greenblatt was to develop a small and simple desalination system powered directly by wind energy. The researchers focused on desalinating brackish water, with a concentration of salts of up to 1% (for reference, the salt concentration in seawater is more than 3%). “We realized that the axis of VAWT can be connected mechanically and directly to a water pump on the ground (without the need to generate electricity to run the pump) which starts the desalination process,” recalls Keisar. That is, in such a setup, the axis that the turbine blades spin around is connected directly to an axis in the water pump. As a first step, the researchers connected a water pump to a VAWT in a wind tunnel (a large channel with a fan in one end that can blow wind at a controlled speed). The pump pressurizes brackish water through a reverse osmosis desalination system – the main kind of system for desalination nowadays, both in Israel and around the world. Reverse osmosis involves using high pressure to drive seawater or brackish water through a partially permeable membrane: water is allowed to flow through it freely, but about 99% of the salts are blocked. After passing through the membrane, water is drinkable and almost completely free of salts.

“We managed to create a system that converts around 12-17% of the input wind energy directly into hydraulic force, for almost any wind speed and an especially wide range of salinity,” says Keisar. “It is as efficient, if not more so, as generating electricity from wind energy and then converting it to hydraulic energy using an electric pump. For example, when wind speed is at 5 meters per second, which is its average speed at Haifa, where our lab is located, the system is capable of producing between 500 and 1000 liters of desalinated water and removing approximately 93-98.5% of the salts (depending on the salinity and pressure of the water).” It is admittedly a very modest amount of water, but consider the fact that the experiment used only a small demonstration system; for a follow-up experiment, the researchers plan to build a bigger system and test it in the Negev or the Arava, for simulation of how it would function in remote places, where such a system could be used to produce fresh drinking water for communities in need.

Good news for the thirsty

This simple system developed by the researchers might be revolutionary at a global scale for its possible use by energy-poor communities with no access to clean fresh water. According to the UN, there are about 1.2 billion people today in such communities, and according to current predictions, this number should grow to about 1.6 billion people by 2030. “Actually, the system we’ve developed works entirely without electricity – none needs to be generated or to be drawn from an external source such as an electric grid or any energy storage system,” says Keisar. “The system is small and relatively cheap because it requires no electronic components. Being mechanical, it is also much easier to maintain and to repair when needed, and it can be set up and taken care of even by people who weren’t extensively trained for that purpose.

The researchers are presently patenting their system, and aiming to commercialize it. The first systems to supply fresh water to communities in need should be up and running in a few years, they hope. According to Keisar, desalination is not the only purpose these systems could serve: “they can also be used for the improvement of drinking water quality in general, as they can be connected to machines able to clean many kinds of pollution from water, thereby purifying it,” he says. “The idea is to develop different systems which combine vertical axis wind turbines with water treatment machines, all simple, inexpensive, and easy to manage.”

This article was prepared by ZAVIT – The News Agency of the Israeli Society of Ecology and Environmental Sciences

Johnathan Sher, Zavit