Quantum Dot Detective Shines at NanoDays 2018

April 17, 2018

by Megan Litwhiler

Back in December, I wrote about our quest to develop our own Museum of Science version of Quantum Dot Detective, a fun, interactive, hands-on quantum dot activity developed by graduate students from MIT.  We were excited to get Quantum Dot Detective up and running for our big NanoDays 2018 event here at the Museum, but we were having some trouble getting the equipment for the activity to work properly. We figured out that our UV lamp was too dim to light up the quantum dots. We needed a brighter UV light that could illuminate the quantum dots from below. With NanoDays fast approaching, we needed to get the problem fixed! 

Luckily, Melany Sponseller, one of the graduate students who originally developed Quantum Dot Detective, volunteered to facilitate the activity at NanoDays, and she graciously offered to help us get the whole set-up in working order before the big day! She came by the Museum of Science before NanoDays to test out our equipment, and she brought in a UV lamp from her lab. We had been using a short wave UV lamp (254nm), but Melany discovered that her long wave UV lamp (365nm) did a much better job of illuminating the quantum dots. The only problem was that, while Melany's long wave UV lamp worked really well, it was also really bright, and we wanted to make sure our visitors were viewing the quantum dots safely. Melany had an ingenious fix for this problem - she designed and 3D-printed a handy holder for the quantum dot cuvettes that allowed the quantum dots to be lit up from below by the lamp, while blocking out the rest of the light!                                                                                                                                                   

Our Quantum Dot Detective set-up was ready for action. Melany and two other grauate students from her lab led the activity at our NanoDays event, and it was a glowing success!

MIT graduate student Melany Sponseller guides Museum of Science visitors through the hands-on activity Quantum Dot Detective at NanoDays 2018. 
In this activity, the visitors become detectives, using a spectrophotometer and optical probe to discover which colors of quantum dots are contained in two different "mystery vials."

 

The optical probe of the spectrophotometer is held up to a cuvette of blue quantum dots (left),
resulting in a high-intensity peak at the blue wavelength on the graph (right). Using a long wave UV lamp,
instead of a short wave UV lamp, solved our lighting problem, and Melany's cuvette holder solved our safety issues.
The quantum dots were beautifully and safely illuminated!

Now that we've solved our lighting issue and successfully debuted our new Quantum Dot Detective set-up with dozens of captivated visitors at our big NanoDays event, we'll be taking this fun, edcuational activity out to the Exhibit Halls here at the Museum of Science every chance we get!