Moments of Happiness at Work
This story was originally published in Russian in January of 2019. I keep telling people about this story because it’s literally one of the highlights of my work at UChicago. Of course, Google Translate works just fine, but I finally decided to tell this story with my own words. Below you can see the original text translated into English. Welcome to the world of nanofabrication magic!
Here’s one funny story from my work at UChicago.
My responsibilities at work mainly include users' support in a huge nanofabrication facility at the University of Chicago. We have many pieces of very complicated and expensive equipment — that’s why we invest a lot of time in trainings, and “Safety first” is our motto. Our users are mostly grad students and postdocs, and they fabricate all sorts of devices in our lab — be it quantum circuits, telescope detectors, or microfluidic structures for cell cultivation.
We also do “remote processing” — this is when a customer is not a user of our facility, and we do all the work for them and then just send them a finished device and an invoice. Usually, such clients are small companies or labs who want to build a prototype of a new device before investing lots of money, time, and effort into real production.
In the fall we got another such request, this time not from a company, but from an individual. His project seemed easy — he wanted to engrave sapphire substrates with patterns that looked like this:
When zoomed in up to single pixels, it looked like this:
The devil was in the details, though. Every pixel is 1x1um in size. The size of the entire pattern — about 1x1 mm. Other patterns looked equally abstract and varied from 0.6x0.6 mm to 2.5x5 mm in size. There were 75 different patterns in total that I needed to put down on a single wafer…
I will skip all the technical difficulties I encountered while trying to make it work… haha! You just get to see the final device! See below :)
The wafer (this is how we call the substrates) is 5 cm in diameter and 440 um (0.44 mm) in thickness, and the depth of the etched structures is 340 nm (this is like a human hair divided into 300 pieces.)
The next part is the most interesting one. The customer asked to test this structure. To do that, one needs to shine laser light through it and see if any image forms on the wall. We were curious too (and I was also super scared that everything failed!). I found a laser pen and, with a pounding heart, got ready to test the results of a few days of work…
At first, I couldn’t see much because the lights were on. I remembered that when my brother and I were kids, we had a laser pointer kit with different pattern heads, and it worked best in the dark. I went to a maintenance room, closed the door, and shut off the lights.
And yay!! The laser needed to be directed at a certain angle to the substrate, that’s why it was not easy to catch a moment when both my and photographer’s (shout out to Mauricio Posada!) hands were not shaking :) but this is what we saw!
The laser light, coming through this pixelated structure, formed images — a photograph of two people! I was stocked — I built something really cool with my own hands and it worked!!!
The customer told me later that this pattern was calculated for a green laser — in that case, the dot in the middle is not visible and the image is more in focus.
When my boss saw it, his first thought was that this was a gift for someone. It was true — both our customer and his girlfriend were physicists, and she liked optics. The guy decided to propose to her and to mount a piece of sapphire with this etched picture into an engagement ring! Scientists can be romantic too :)
When I sent him that picture, he replied (his spelling):
“Hi Anna,
COooooooll!!!!! IT WORKED!!!! wooohoooo!!!”
The dude was definitely euphoric that his crazy idea worked, and I wished him she’d say “yes” :)