Week 5: Initial Observations

Welcome back to my blog! This week I was able to observe and characterize the microspheres I made from my methodology.

After discussing with my mentor, we decided that the best techniques for microsphere characterization given the available equipment in the lab would be dynamic light scattering, scanning electron microscopy, and light microscopy. Dynamic light scattering (DLS) can help to  determine the size distribution profile of the microspheres; scanning electron microscopy (SEM) can provide detailed images of the surfaces of the microspheres in order to assess their surface topography and composition; and light microscopy (LM) can visualize the fine details of the microspheres.

In order to carry out all these techniques, I had to receive training on how to use the different equipment. For this week, I was first trained on the SEM and cleanroom procedures (where the SEM was located). To image my microspheres, I added 100 μl of the silk microsphere suspension directly on top of conductive tape mounted on a SEM sample. The samples were dried overnight in air, sputtered with platinum, then imaged using the software in the SEM. Below are some of the images of SF microspheres I successfully fabricated that I took from the SEM! It was super exciting to actually be able to visualize the microspheres!

As you may notice in the images, these initial samples of the SF microspheres had wide-ranging sizes and were agglomerated and clustered together. Using the software from the SEM, I was able to quantifiably observe the microspheres. There were some microspheres as small as 0.857 μm in diameter, to being as large as 15.110 μm in diameter. Based on these observations as well as the ones I will get from doing DLS and LM, I will adjust some parts of the methodology to improve the sizing and spread of the microspheres.

Next week, I will take on doing the DLS and LM on these initial trials and begin to brainstorm changes I can make in the methodology. Thanks for reading!