Researchers clear up glassy surfaces question

by Victoria Van Cappellen, Science Communications.

University of Waterloo physicists have succeeded in measuring how the surfaces of glassy materials flow like a liquid, even when they should be solid.

A series of simple and elegant experiments were the solution to a problem that has been plaguing condensed matter physicists for the past 20 years.

This work is the culmination of a project carried out by research team involving the University of Waterloo, ESPCI (Paris) and McMaster University. Leading the team are Professor James Forrest and doctoral student Yu Chai, from the Department of Physics and Astronomy in the Faculty of Science. Forrest is also an associate faculty member at the Perimeter Institute.

Their groundbreaking work was published in the prestigious scientific journal, Science.

“Glasses are fascinating materials. At low temperatures they’re solid, and at higher temperatures they’re liquid. At intermediate temperatures, it’s hard to consider them as only one or the other,” said Forrest. The above image shows how the top surface of a glassy polymer flattens over time like a liquid.

Glasses are much more than the silicon-based materials in bottles and windows. In fact, any solid without an ordered, crystalline structure is considered a glassy material. Metals, small molecules, and polymers can all be made into glassy materials.

Polymers, the building block of all plastics, are almost always glassy rather than crystalline. These materials undergo a transition between a brittle solid and a molten liquid in a narrow temperature range which encompasses the so called glass transition temperature.

“Surfaces of glassy polymers shouldn’t flow below the glass transition temperature, but they do. The question is why,” said Forrest.

In this series of experiments, Forrest and colleagues started with very thin slices of the glassy polymer polystyrene stacked to create tiny staircase-like steps about 100-nanometres high, and then they measured these steps as they became shorter, wider and less defined over time. A video showing this polymer step levelling in action is posted on YouTube.

One nanometre equals one billionth of a metre. In comparison, one human hair is about 80,000 nanometres thick.

The simple 2-dimensional profile of this surface step allowed the physicists to numerically model the changes to the surface’s geometry above and below the glass transition temperature.

Results show that above the transition temperature, polystyrene flows entirely like a liquid; but below this temperature the polymer becomes a solid with a thin liquid-like layer at the surface.

Understanding the mobility of glassy surfaces has implications for the design and manufacture of thin-film coatings and also sets real practical limits on how small we can make nanoscale devices and circuitry.

Being able to calculate how these nanostructures may evolve over time and under what conditions will bring engineers a step further towards making nanotechnology an everyday reality.

Forrest is also a University Research Chair and member of the Waterloo Institute for Nanotechnology.

The project team also includes Kari Dalnoki-Veress and J.D. McGraw from McMaster University and Thomas Salez, Michael Benzaquen and Elie Raphael of the École Superieure de Physique et de Chimie Industrielles in Paris.

 

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Changing the world in 2 weeks with IDEAS

by Sammi Zhao.

This July, the University of Waterloo is introducing the IDEAS Summer Experience, a 2-week summer program for international high school students.

In keeping with Waterloo’s innovative spirit, IDEAS is designed to help students discover their own big ideas. Participants will be presented with some of the world’s most pressing problems and will select a ‘big problem’ that they will focus on for the 2 weeks. The students will work together to try and discover their ‘big idea’ to solve ‘the big problem’.

IDEAS will introduce high school students to each faculty at Waterloo through daily hands-on learning sessions. The goal is to use Waterloo’s diverse range of studies to show the many ways one can understand ‘the big problem’. IDEAS will help participants build innovative problem-solving skills by encouraging students to adopt a multidisciplinary perspective.

Waterloo’s focus on experiential learning is also embraced by the hands-on learning sessions in IDEAS. The daily hands-on sessions are designed to be engaging and interactive to maximize the students’ involvement in their own learning experience.

Simultaneously, IDEAS also aims to provide an environment that encourages collaborative learning. Students will live in an on-campus residence, go on off-campus excursions to visit popular landmarks such as Niagara Falls, and participate in social activities together.

Introducing IDEAS is a step towards Waterloo’s goal to becoming Canada’s most internationalized university. It enables the University to reach out to international students earlier on in high school and allows students to experience university life in Canada.

IDEAS is now accepting applications. If you know an international student in grade 10 or 11 who may be interested in IDEAS please tell them about the IDEAS Summer Experience website where they can find more information and apply! Applications are due by March 31st. For any questions please contact Mirjana Radulovic from Marketing and Undergraduate Recruitment or Julie Hummel from Waterloo International.

 

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When gaming can make a difference

Landing on Boardwalk. Shooting down a space invader. Finding a 1UP mushroom. Getting five headshots in a row. Moving the robber to an opponent's territory. When it comes to games, the play's the thing, but so is the thrill of victory.

The idea of applying game-like rewards to motivate engagement is nothing new. That's called gamification, the concept of using a gameful or playful layer to motivate within specific contexts. Typical gamification applications usually focuses on points or badges to entice users. This can be effective in the short term, but has several problems when thinking about long-term change.

With that in mind, the Games Institute has invited Scott Nicholson, director of the Because Play Matters game lab and associate professor at the School of Information Studies at Syracuse University to deliver a talk entitled "From Points to Play: Using Meaningful Gamification to Make a Difference" today.

In his talk, Nicholson will first describe reward-based gamification, then present some of the problems with a reliance upon rewards, and then explore his own work into Meaningful Gamification, which is the use of game elements other than rewards to engage users in the long term.

Nicholson is the author of Everyone Plays at the Library, is the designer of the published board games Going, Going, Gone! and Tulipmania 1637, and was the host of the web series Board Games with Scott.

The talk takes place from 2:00 p.m. to 3:00 p.m. today in DC 1304 and will be livestreamed. Tickets are available online.

 

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Talking entrepreneurship at town hall meeting

The first in a series of mini town hall meetings about the implementation of the University's Strategic Plan took place on Thursday, March 6 in the Velocity residence great hall. Speakers included President Feridun Hamdullahpur, Howard Armitage, special advisor to the President, Bud Walker, special advisor to the Provost, Doug Sparkes, associate director, MBET program at Conrad, Mike Kirkup, director, Velocity and Student Innovation; and Geoff Malleck, professor in the economics department.

The town hall provided an opportunity to have a discussion about how the theme of entrepreneurship fits into the overall plan and why it is vital to the University.

After introductory remarks by Feridun Hamdullahpur and a stage-setting overview by Howard Armitage (pictured above) that outlined the progress that has been made on the theme so far, the entrepreneurship working group members took questions from the floor, from Twitter, and from email.

More information about the entrepreneurship town hall, including the full video of the event, can be found on the Strategic Plan website.

The next mini town hall, focused on Transformational Research, is scheduled for Tuesday, March 18, from 2:00 to 3:00 p.m. in the lower atrium of the Mike & Ophelia Lazaridis Quantum-Nano Centre.

 

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Looking for student ambassadors and other notes

You've seen them. Leading a group of future students with their parents in tow, a young but wise-beyond-their-years University of Waterloo student makes a spirited sales pitch as they conduct a tour of campus. They are the few, the proud, the Student Ambassadors.

Applications for the Student Ambassador positions for 2014-2015 have opened on Find Out More. Students who are passionate about Waterloo and sharing their experiences with prospective students and parents would be a great fit for the ambassador team.

Applications are due in the Visitor's Centre by Thursday, March 13 at 4:30 p.m., with interviews taking place the week after.

Here's the latest Nutrition Month "myth vs. fact" from Health Services dietician Sandra Ace:

Myth: Poultry should always be rinsed before cooking.

Truth:  Raw chicken or turkey should not be rinsed before cooking; doing so can spread bacteria and create more of a safety hazard. Poultry is a versatile and healthy choice that many Canadians enjoy regularly. However, poultry can cause food poisoning if it isn’t stored and prepared properly. Be sure to keep your poultry meals safe by following these food safety tips.

 

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