Declassified Career Survival Guide: Anna Alvarez

Many people talk about having summer internships, but have you ever considered doing summer research? Research Experiences for Undergraduates (REUs) are programs that offer undergraduate students hands-on research experience, which is great for people interested in both industry and graduate school.

This summer, MechSE junior Anna Alvarez participated in the Cornell Nanoscale Facility (CNF) REU, where she worked in the field of nano-fabrication with Associate Professor Itai Cohen and mentor Qingkun Liu, both from the Cornell Physics Department. Anna’s project, titled “Light and Thermal Responsive Liquid Crystal Films for Micro Robotic Applications,” allowed her to get in-depth experience with microscale design and manufacturing techniques.

You may have heard of liquid crystal (LC) inside of screens or smartphone displays, but LC is also a state of matter. It's a state only certain polymers can achieve—between solid crystal phase and isotropic liquid phase.

These polymers are special because the central mesogen, which is the body of the polymer, is rod-like or disk-like in shape. In liquid phase, these rods are randomly organized because they're swimming around. But when you reach LC and solid crystal phase, they line up. Since all these rods are pointing in one direction, the material is thus stretched a bit in that direction, and deformation occurs. 

Why does it matter that it's in LC phase and not solid crystal? In both phases, the mesogens line up. However, the LC phase still allows connections between monomers to be flexible – meaning the material is still responsive and can be deformed.

Using the CNF clean room, Anna developed a liquid crystal precursor that she would pattern using photolithography. She then was challenged with aligning the liquid crystals to allow the material to contract in the direction they needed for this specific design. Initially, she was able to use a velvet block to align the crystals along the entire part, but that method was not accurate enough for the patterns she was looking to create. After some trials, she managed to create a silicon chip that had trench-like micro-structures that allowed the liquid crystals to be aligned in specific patterns. Using this silicon chip, Anna was able to make her first micro-bot, which would curl up when heated. (She named it HugBot.) 

While she accomplished a lot during her time at Cornell, there is more to be done on the project. The goal is to make the liquid crystal photo-responsive, so that it curls when exposed to light, since it is difficult and more unreliable to create a heat-driven device. Anna developed a procedure of what needs to be tested going forward.

Anna really enjoyed her time at CNF and appreciated the opportunity to do impactful work. 

“One thing that really cool about my REU experience is that I felt like the research I did over the summer was valuable. This is the first time anyone has made a micro-robot out of liquid crystal. It's a new material and a new fabrication method we're making for micro-scale devices. Once it becomes light activated, it really opens up possibilities for designing future micro-robots.”

At the end of her REU, Anna was able to present her findings at the NCCI REU Convocation. If you would like to watch a recording of her presentation, you can find it at this link, starting at 13:48 minutes:

https://cornell.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=c5e39749-a460-437a-8d03-aaa1012d4551 

If Anna’s REU experience interested you, the 2020 CNF, KEP, & PARADIM REU application can be found at http://reu.nnin.org/nnin11_login.php.

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