While some kids spend their summer days watching TV or playing video games, a few lucky students enrolled in U of T’s Da Vinci Engineering Enrichment Program (DEEP) Summer Academy are doing something amazing: they’re learning hands-on about some of engineering’s most fascinating, innovative research.
As part of the summer program, participants learn about the field of engineering from U of T Engineering students and take part in intriguing activities, like the exclusive tour of Insception Cord Blood Program’s facilities that took place on July 8.
The tour was part of a course called Stem Cells: the Past, Present and Future. The one-week class teaches DEEP participants about the research history and ethical, social and legal aspects surrounding stem cell work.
Find out more about DEEP and other U of T Engineering pre-university programs here
University of Toronto researchers have derived inspiration from the photosynthetic apparatus in plants to engineer a new generation of nanomaterials that control and direct the energy absorbed from light.
Their findings are reported in Nature Nanotechnology , released on July 10, 2011.
The U of T researchers, led by Professors Shana Kelley and Ted Sargent, report the construction of what they term “artificial molecules.”
“Nanotechnologists have for many years been captivated by quantum dots – particles of semiconductor that can absorb and emit light efficiently, and at custom-chosen wavelengths,” explained co-author Kelley, a Professor at the Leslie Dan Faculty of Pharmacy, the Department of Biochemistry in the Faculty of Medicine, and the Department of Chemistry in the Faculty of Arts & Science. “What the community has lacked – until now – is a strategy to build higher-order structures, or complexes, out of multiple different types of quantum dots. This discovery fills that gap.”
The team combined its expertise in DNA and in semiconductors to invent a generalized strategy to bind certain classes of nanoparticles to one another.
“The credit for this remarkable result actually goes to DNA: its high degree of specificity – its willingness to bind only to a complementary sequence – enabled us to build rationally-engineered, designer structures out of nanomaterials,” said Sargent, a Professor in The Edward S. Rogers Sr. Department of Electrical & Computer Engineering at the University of Toronto, who is also the Canada Research Chair in Nanotechnology. “The amazing thing is that our antennas built themselves – we coated different classes of nanoparticles with selected sequences of DNA, combined the different families in one beaker, and nature took its course. The result is a beautiful new set of self-assembled materials with exciting properties.”
Traditional antennas increase the amount of an electromagnetic wave – such as a radio frequency – that is absorbed, and then funnel that energy to a circuit. The U of T nanoantennas instead increased the amount of light that is absorbed and funneled it to a single site within their molecule-like complexes. This concept is already used in nature in light harvesting antennas, constituents of leaves that make photosynthesis efficient. “Like the antennas in radios and mobile phones, our complexes captured dispersed energy and concentrated it to a desired location. Like the light harvesting antennas in the leaves of a tree, our complexes do so using wavelengths found in sunlight,” explained Sargent.
“Professors Kelley and Sargent have invented a novel class of materials with entirely new properties. Their insight and innovative research demonstrates why the University of Toronto leads in the field of nanotechnology,” said Professor Henry Mann, Dean of the Leslie Dan Faculty of Pharmacy.
“This is a terrific piece of work that demonstrates our growing ability to assemble precise structures, to tailor their properties, and to build in the capability to control these properties using external stimuli,” noted Paul S. Weiss, Fred Kavli Chair in NanoSystems Sciences at UCLA and Director of the California NanoSystems Institute.
Kelley explained that the concept published in Nature Nanotechnology is a broad one that goes beyond light antennas alone.
“What this work shows is that our capacity to manipulate materials at the nanoscale is limited only by human imagination. If semiconductor quantum dots are artificial atoms, then we have rationally synthesized artificial molecules from these versatile building blocks.”
Also contributing to the paper were researchers Sjoerd Hoogland and Armin Fischer of The Edward S. Rogers Sr. Department of Electrical & Computer Engineering, and Grigory Tikhomirov and P. E. Lee of the Leslie Dan Faculty of Pharmacy.
The publication was based in part on work supported by the Ontario Research Fund Research Excellence Program, the Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Research Chairs program and the National Institutes of Health (NIH).
Find out more about their work in the following selection of stories:
AZnano
BioScholar News
IEEE Spectrum
GeekoSystem
Nanowerk
Nanotechweb
Popular Science
Science Daily
Lead researcher and Principal Investigator Professor Brent Sleep (CivE) has been awarded $3,213,700 by the Ontario Research Fund – Research Excellence (ORF-RE) Water Round program.
He and his team, made up of seven co-investigators from Queen’s University, University of Waterloo and U of T, will investigate combined treatment technologies for remediating contaminated groundwater in Ontario.
“This grant is important because it will help us train and educate students, and help redevelop industrial lands that have languished untreated in the province,” said Professor Brent Sleep.
Within Canada, there are an estimated 30,000 contaminated water and soil sites known as ‘brownfields’ that contain hazardous chemicals such as chlorinated solvents and hydrocarbons such as coal tars. To make these often vacant and underused sites ready for redevelopment, governments and companies spend considerable amounts of money to clean them up. In some cases these sites remain polluted for decades, making the cleaning process that much more difficult and costly.
Professor Sleep’s work has the potential to create more cost-effective water treatment technologies using an innovative combination of promising methods based on physical biological and chemical processes.
The project will also develop monitoring techniques to assess the impact of water treatment technologies on pollutant removal.
“Early industrial operations in Canada and around the world did not have the same sense of environmental stewardship that we have today,” said Professor Brenda McCabe, Chair of the Department of Civil Engineering. “We are extremely proud of Professor Brent Sleep whose research will help Ontario and Canada stay at the forefront by developing new and effective ways to remediate brownfield sites for a healthy and successful economy.”
For more information about the project, please visit the Ministry of Research & Innovation
In a paper published in Nature Photonics, U of T Engineering researchers report a new solar cell that may pave the way to inexpensive coatings that efficiently convert the sun’s rays to electricity.
The U of T Engineers, led by Professor Ted Sargent (ECE PhD 9T8), report the first efficient tandem solar cell based on colloidal quantum dots (CQD). “The U of T device is a stack of two light-absorbing layers – one tuned to capture the sun’s visible rays, the other engineered to harvest the half of the sun’s power that lies in the infrared,” said lead coauthor Dr. Xihua Wang.
“We needed a breakthrough in architecting the interface between the visible and infrared junction,” said Sargent, a Professor of Electrical and Computer Engineering at the University of Toronto, who is also the Canada Research Chair in Nanotechnology. “The team engineered a cascade – really a waterfall – of nanometers-thick materials to shuttle electrons between the visible and infrared layers.”
According to doctoral student and lead coauthor Ghada Koleilat, (ECE MEng 2T8, PhD Candidate) “We needed a new strategy – which we call the Graded Recombination Layer – so that our visible and infrared light-harvesters could be linked together efficiently, without any compromise to either layer.”
The team pioneered solar cells made using CQDs, nanoscale materials that can readily be tuned to respond to specific wavelengths of the visible and invisible spectrum. By capturing such a broad range of light waves – wider than normal solar cells – tandem CQD solar cells can in principle reach up to 42% efficiencies. The best single-junction solar cells are constrained to a maximum of 31% efficiency. In reality, solar cells that are on the roofs of houses and in consumer products have 14 to 18% efficiency. The work expands the Toronto team’s world-leading 5.6 % efficient colloidal quantum dot solar cells.
“Building efficient, cost-effective solar cells is a grand global challenge. The University of Toronto is extremely proud of its world-class leadership in the field,” said Professor Farid Najm, Chair of The Edward S. Rogers Sr. Department of Electrical & Computer Engineering.
Sargent is hopeful that in five years solar cells using the graded recombination layer published in Nature Photonics paper will be integrated into building materials, automobiles and mobile devices.
“The solar community – and the world – needs a solar cell that is over 10 per cent efficient, and that dramatically improves on today’s photovoltaic module price points,” said Sargent. “This advance lights up a practical path to engineering high-efficiency solar cells that make the best use of the diverse photons making up the sun’s broad palette.”
The publication was based in part on work supported by an award made by the King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund Research Excellence Program, and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. Equipment from Angstrom Engineering and Innovative Technology enabled the research.
Watch Professor Ted Sargent describe the first efficient tandem solar cell based on colloidal quantum dots (CQD):
On June 9 and 10, 2011, the Faculty of Applied Science & Engineering hosted the 10th anniversary of UT², a graduate student conference held annually between the University of Tokyo and the University of Toronto.
The event provides graduate students and faculty members with opportunities to meet and discuss ideas with experts within their field and promotes international research collaboration and exchange.
The conference, which both participating universities alternate hosting, initially began in 2001 as a workshop for Materials Science & Engineering (MSE) students at both institutions but soon evolved into a Faculty-wide initiative. Graduate students and faculty members from the Department of Chemical Engineering & Applied Chemistry (ChemE) and the Department of Mechanical & Industrial Engineering (MIE) joined the conference in later years, with participants able to also independently organize exchanges throughout the year.
Eric Morris (ChemE PhD Candidate), a UT² Planning Committee Member, sees the annual event as invaluable experience for U of T Engineering. “This conference is a great way for graduate students to see how things are done at a different institution in a different country,” said Morris. “Not only does this help to broaden our horizons, but it also opens the door for new ideas and new collaborative research opportunities.” This year’s UT² Planning Committee Members also included Yuki Kuwauchi (MSE MASc Candidate), Leili Tafaghodikhajavi (MSE PhD Candidate) and Reza Rizvi (MechE PhD Candidate).
Professor Jun Nogami, Chair of the Department of Materials Science & Engineering, agrees. “Our relationship with Tokyo is a great opportunity to further our goals in internationalizing our research, our programs for graduate students, and eventually, our undergraduate students,” he said.
Cristina Amon, Dean of the Faculty of Applied Science & Engineering offered her thanks to the staff and faculty who organized this year’s and past UT² events. “Our engineers are often at the forefront of research and collaborations within, and outside, U of T. Congratulations to the faculty, staff and students who have made 10 years of excellent exchanges possible.”
City crews will be examining sections of the Gardiner Expressway after a 4.5-kilogram chunk of concrete fell onto Lake Shore Blvd. W. on Monday, hitting a guardrail and ricocheting into the road.
Aside from the dangers inherent in a chunk of concrete weighing almost as much as a bowling ball falling from the sky, the expressway itself is sound. This is according to Professor R. Doug Hooton (CivE), who provides expert comment.
To read the full story, visit the Toronto Star.