THE FINALE! DAY 10!

Today is a really short day but nonetheless, it was still a fun day! Huaqiong, our next mentor, showed us how to use the scanning electron microscope. Before using it, we had to prepare our scaffolds so that they will be conductive.

1. Placed our scaffolds on the SEM holder with carbon tape, some of them were facing up, some down.
2. Placed it in a sputter coater. We couldn't do it in one go as the temperature generated might melt the polymer. So we did in twice for 40 seconds each time. WE ARE COATING THEM IN GOLD! Under low vacuum, the gas molecules are ionised by electrical field and positive ions are attracted to the gold target held at negative bias, the gold atoms will be sputtered out and deposited on the sample surface.

The SEM holder with the scaffold samples. It is taped to carbon tape. Apparently, there are silver tapes and other kinds as well.

This is the sputter coater. They are different kinds, some coats the sample with carbon, others with gold. This one coats gold.

Operation manual

How to determine the thickness of the coating.

Before

After (it doesn't look very gold-ish)

After preparation, we could finally use the SEM. Usually, we are looking at secondary and backscattered electrons to determine the topography and composition of the scaffold respectively. For the secondary electrons image, we see our cells in 3D! Some of them are stuck in the midst of mitosis.

SEM. Sorry for the bad quality, it was taken in the dark and Karmen didn't want to scare the others by turning on the flash. 

BTW the SEM is kept in a dark and cold room. Dark because light might affect the quality of the images. Cold because large amounts of energy is released when the electron beam is released. So liquid nitrogen is also used to cool the microscope lens to protect it from any harm.

The stage of the SEM. It is sealed by vacuum.

How to use the SEM. We got to try to use it. Karmen sucked at using it. HAHA.

All the images we took. SO COOL! ><

The scaffold here is the one we used electrospinning to make on Day 2. So there are aligned. 

The fibres here looks flat because the scaffold was subjected to heat treatment. So the fibres melted. 

These are scaffolds with no cells on it. 

Fibroblast attached to the scaffold. Fibroblast is spindle-shaped when attached. 

We are guessing that the two cells are undergoing mitosis. They are already dead though.

These are fibroblast that are attached to the scaffold. 

SO CUTE! Huaqiong says it looks like ice cream. HEHE.

So today is really really short and hence we don't have much to share. But we will be posting our reflections and thoughts of the entire programme.

With this last post, we have come to the end of our research shadowing programme. We are really grateful to all the people who were involved in this. Thank you for organising this programme! Thank you for spending time with us! Thank you for your patience! Thank you for your mentorship and guidance! Thank you for sharing with us! We have a lot to say thank you for. We will always remember the time we spent here in NTU (both MSE and SBS). We have enjoyed sharing with all of your readers and we are also grateful for your support! We will see you again sometime and we wish all of you people out there all the best and a merry christmas!