Creating 3D nanostructures for the next generation of nanotechnology
Asst. Prof. Tamar Segal-Peretz develops nanotechnology for conserving resources and streamlining diverse technologies: from computers and optical devices to efficient membranes for water treatment.
After completing a BSc in Biochemical Engineering at the Technion, Tamar Segal-Peretz worked in industry and felt she wanted to delve deeper into research. She decided to pursue a graduate degree. “I felt that graduate studies would open new doors for me. Therefore, I decided to return to the Technion and joined one of the first classes of the Interdisciplinary Program for Nanoscience and Nanotechnology, in Prof. Gitti Frey’s research group at the Department of Materials Science and Engineering,” says Tamar. “During my PhD research, which dealt with the self-assembly of polymers to create solar cells, I realized that I really enjoy studying and discovering new things, as well as teaching courses and mentoring students in the lab. Towards the end of my graduate studies, I decided to pursue an academic career. The field of polymer self-assembly was very attractive to me, so I joined Prof. Paul Nealy’s lab at the University of Chicago and Argonne National Laboratory as a postdoctoral researcher focusing on this subject. We studied the integration of self-assembled polymers into advanced computer chip manufacturing processes.” After three years in Chicago, Tamar returned to Israel with her family and joined the Technion’s Department of Chemical Engineering as a faculty member, where she opened The Functional Nanostructures and Advanced Imaging Lab. In addition to research and teaching in the fields of nano, polymers, electron microscopy, and separation processes, Tamar also established a Women’s Forum in Chemical Chemical Engineering for graduate students at the department, where senior and trainee academic women meet, share advice, and develop ways to support each other.
The research conducted in Asst. Prof. Segal-Peretz’s group is focused on the development of nanotechnology to reduce resource consumption and streamline various technologies. “The expanding world population and our responsibility towards the planet requires us to find efficient ways to utilize the existing resources while preserving the environment,” says Tamar. “The vast majority of the processes that take place in technological devices occur at the nanoscale – electrons, photons, and molecules at this scale dictate how devices work – from computers and optical devices to water treatment membranes and heat management devices. Our studies are based on the formation of nanometer structures from polymers (for example, by self-assembly of block co-polymers) and on the growth of inorganic materials on and inside polymers, using the atomic layer deposition (ALD) technique. “Growing inorganic materials within organic polymers allows us to tailor the properties of the final product, as well as to devise innovative ways to create durable and strong nanostructures from soft and easy-to-apply polymers.” The research group frequently uses electron microscopy to characterize nanostructures with expertise in 3D nanomaterial characterization. Three-dimensional characterization at the nanoscale allows researchers to accurately understand the structures they create, and thus optimize the design.
For example, these methods can produce membranes that repel oil molecules – thus protecting themselves from contamination, as well as membranes for molecular separation for nanometric pollutants molecules removal such as drugs residues. Other topics studied at the lab are the fabrication of ceramic fibers with a 3D structure from simple polymer fibers – which allows for excellent control over the fibers’ structure and composition, three-dimensional characterization of nanostructures for the semiconductor industry (in collaboration with Applied Materials and Intel), and development of structures and materials with improved mechanical properties that can be used for energy absorption and durable protective layers. These technological developments enable new types of 3D nanostructures- one can think of it as 3D printing at the nano-scale.
Segal-Peretz’s research group works in cutting edge, diverse fields Until a few years ago, scientists didn’t think that inorganic materials could grow within polymers using ALD (atomic layer deposition) technology, but research in Tamar’s group and other groups around the world has opened a host of new possibilities for creating hybrid materials with improved properties. “In five to ten years, I expect we will be able to perform ALD in polymers with a wide range of materials and in a scalable manner (such as roll-to-roll), leading to efficient manufacturing of functional 3D nanostructures. In computer chip manufacturing, for example, devices are becoming more complex; thus, a 3D understanding at the material level is vital and there is a great need for new 3D nanofabrication technologies. A new field that the research group is now entering is biodegradable polymers and “green hybrid materials that will reduce plastic pollution while maintaining plastic-like performance.
“I strongly believe in collaborations because today’s research is very multidisciplinary. It is crucial to work with experts from different fields and contribute our expertise to other groups. It is also very fun and instructive, both for me and for the students,” says Tamar. The research group collaborates with Prof. Guy Ramon (Civil and Environmental Engineering), Prof. Eyal Sussman (Mechanical Engineering), Prof. Noy Cohen (Science and Materials Engineering), and Asst. Prof. Shady Farah and Prof. Slava Freger from the Technion Department of Chemical Engineering. At the national level, there are collaborations in the field of batteries with Prof. Daniel Sharon of The Hebrew University of Jerusalem. The group also has many international collaborations (with groups in Germany and United States). “It’s fun to work with people at the forefront of global research. In addition, we collaborate with a variety of companies from the Israeli industry – Shamir Optical Industry, Applied Materials, Intel, and Elbit.”
The main methods used in the group are techniques for polymer engineering (self-assembly of a block co-polymers to create nanometer structures in thin layers and in particles, electrospinning, 3D printing, and working with polymer membranes), together with techniques for growing inorganic materials on and inside polymers using ALD-based processes. The ALD enables a solvent-less procedure, which is significantly more environmentally friendly than working with organic solvents. ALD processes allow precise (sub-nanometer) control over the thickness of the material and its nature. “In addition, we perform many characterizations using electron microscopy methods: scanning electron microscope (SEM), transmission electron microscope (TEM), and also a microscope capable of performing precise cutting (focused ion beam, FIB).”
Asst. Prof. Segal-Peretz’s research group has students with diverse academic backgrounds, mainly in Chemical Engineering and Materials Science and Engineering. Courses on polymers, solid-state and microscopy are good preparation for working in the group, but even those who arrive without prior knowledge of these topics can thrive and deepen their knowledge while working in the lab. “I believe that a graduate degree (MSc/PhD) is a great opportunity to acquire new skills and learn new fields. “Nourishing your research project is hard work, and it’s a wonderful feeling when you succeed in creating new scientific knowledge or in developing new technology. The Technion Department of Chemical Engineering is a great home to work in while being at the forefront of cutting-edge science. I invite ambitious candidates to join us!”
Tamar advises students who are debating between several areas of research: “It is important to choose a research topic that interests you and that is meaningful to you, as well as to choose a group and a mentor that you will enjoy working with during the graduate studies period.”