Day 9 and 10

Day 9

The second last day of our job shadowing! We followed up on the work we left off yesterday. As the Ph.D student had completed spinning the fibres on the rotating disc, the aluminium foil was coated white! We then went to the basement of the building, where all the big machines are being held as we had to use the Scanning Electron Microscope to view the fibres deposited on the foil for deformities as well as observe its fine structure. But before that, we cut up the foil into smaller pieces and coated it with a layer of gold so that the fibres become conducting, allowing it to be viewed under the microscope which required the samples to be electrically conductive.

Sputtering underway. Creepy purple light coming from the machine :o

Even after applying the thin film of gold the foil still looked quite the same!

Then, we viewed the fibres under the SEM to check for any deformity and were certainly impressed! The fibres were so small and well aligned and it was actually quite stunning. This SEM can go up to 300,000x magnification! How cool is that!

The spun fibre under the SEM!

Day 10

Its the last day of our 2 weeks job shadowing, and to end it off, we went to the animal house where all the mice and rats were kept for experiments. Initially, we thought it would be like a zoo visit. Who would have thought it was more than that.

We had to sign in and wear all the protective gear, like the surgical coat, hairnet, masks, gloves and shoe coverings. As we geared up and sprayed ethanol solution to disinfect ourselves, we then went into the animal house. There was this weird stench when we went it, but got used to it soon after. So, we first visited the room where they kept the mice and the stench was overwhelming due to the concentration of pee in the air. Dr Ivan then took out some hairless mice that was being bred specially so they have low immunity. We observed the mice moving about and then proceeded to watch some other researchers counting the new born mice and accounting for all of them. The newborns were sooooooo small and weighed about 1 grams each!

Next, we then went to see the rats who are larger in proportion. After that, we left the facility and went back to the labs where we received our certificates of participation and that marks the end of our job shadowing at NTU material science engineering school.

The whole 2 weeks were an eye opener and we learnt alot of things, from composite materials to biological materials. The process was made so insightful and interesting by our two mentors, Dr Jason Cheah and Dr Ivan Lam and the other researchers and Ph.D. students. We will definitely recommend our juniors to uptake this eventful shadowing attachment!

:)

DAY 8

Today we saw the result of the staining test. We washed the samples with PBS twice to wash away the staining solution. Then, PBS was added to keep the solution moist to prevent the cells from drying up.

We then used a microscope to see the cells, the aged cells were stained with a greenish blue colouration while the new cells were not stained.

New cells with a relatively massive crystal of x-gal!

 Stained aged cells

We then saw another experiment being conducted. This experiment creates cells arranged in a pattern. This pattern allows stem cells to be made into long chains. This can be used to replicate the cells in the heart muscles. This is to come closer to the ability of solving the problems of muscle damage after a heart attack, as the muscle do not readily repair itself like in other tissues.

This also brings us to the topic of 3D printing of cells. It brings us closer to that future, yet the problem is to align cells into a nice pattern just like our organs and tissues.

Back to the pattern printing, the process includes a red solution to be added to the cell. UV light is then used to provide sufficient energy to achieve the activation energy required for binding to occur. This solution allows the cells that are on the pattern to bind to the treated gel.

Prior to stamping the pattern, a hard silicon gel with microscopic imprints is added in an organic solvent and ultrasound is used to agitate the solution and wash away any minute dust particles or impurities on the silicon. The silicon contains the pattern required and is stamped on the PA-gel with mixture in between. He then put it under weights for 40-50 minutes to create the micropattern onto the PA-gel.

Later in the afternoon, we were brought to the lab and introduce to the concept of electrospinning. It involves bringing a solution of dissolved fibre particles to such a high electrical potential that the solution repels itself and is effectively "shot" out of a fine nozzle onto the oppositely charged spinning plate to be collected as a long and extremely thin thread. In fact, the thread was so thin we could barely see it during the spinning and we had to observe it under the microscope instead! In order to prepare the solution, the fibre particles were dissolved in a solution of chloroform. We were told the process would take 7 hours! Thankfully, a solution was already prepared a day before so we didn't have to wait. While waiting the the solution to be entirely spun out, our mentor introduced us the the instruments used in the lab such as a vacuum pump for vacuum drying samples, an spinning agitator for dissolving solutes, a giant centrifuge and also an autoclave machine for sterilizing any biohazardous waste or equipment! He also brought us a sample of hydrophobic material that as its name suggests, is able to prevent water from sticking to the surface and causes them to form spheres that roll off quickly.

Spinning in progress!

The spun fibres under a microscope

 Our first experience with super hydrophobic material

DAY 7

After an eventful day 1 in the Bio materials department, we came back today again :) So, after our cells have been incubated for about a day, we took them out for staining and also oxidative stress testing.

 As we have prepared many small samples the day before, we also prepared solutions of different concentrations of hydrogen peroxide to subject it for oxidative stress test and to make it grow old, otherwise known as senescence. The young foreskin cells are able to undergo senescence as they still have the potential to grow older, yet the aged cells are unable to undergo senescence and are in a 'neither here nor there' state as they are unable to die unlike the younger cells. One interesting thing about cancer cells is that they do not age unlike our normal cells and this characteristic alongside with its evasion capabilities make it very difficult for us to tackle it. As Dr Lam's student carried out the repetitive process of injecting the hydrogen peroxide solution into the samples, growth factors are added. These growth factors originates from cow. We had a light hearted talking session with him, to learn more about material science and what are the various avenues we can pursue in the future

Biomaterials is a very unique type of material science, unlike the defense materials or sustainable energy materials where they can yield a final product, biomaterials is more about the basic scientific research. Futhermore, we cannot just imagine science and business to be in different spheres of life as they are often interrelated. Some business fields require people from scientific backgrounds to aid them and for research to be commercialize, there need to be a link with people from the business sector. This insightful food for thought given by our mentor kept us thinking, providing us a clearer understanding on what do we want to pursue in the future. He also mentioned about the course to become a PhD. Moreover, he mentioned about how research is an expensive industry. Equipment and consumables all require funding and these funding usually comes from the government. Furthermore, the research that are given more attention to are those that affects the country and the development .of the country. These research usually produce something that can be materialized and commercialized.

As we were rounding up our talk, Dr Lam's student was also nearly done with his work. He then placed the samples with hydrogen peroxide solution into the incubator as it will take time, so we can then see the results of the work tomorrow.

Then, we proceeded to another lab to conduct the senescence beta galactosidase staining. We first removed the growth media from the cells and rinsed them with PBS twice to ensure the growth medium is completely cleansed, then we added staining solution and allowed it to incubate at 37 degrees for another night so we will only view the results tomorrow as well.

We were taught about fixing solution. It is a kind of reagent that freeze the item in a state where it can be observed. The fixing solution can only freeze and prolong this effect for 10-15 minutes, beyond that will cause the solution to 'overfix'. The most interesting part is that the fixing solution actually kills the cell, yet it sustain the cell to a "frozen" state.

With that we completed our day and we are looking forward to day 3 :)

Fixed cells under the staining solution!

DAY 6

'Start of something new'

Week 2 of our attachment! A new week, a new beginning as we are about to embark on our journey as research scientists in the biology field. 

At 9.30am, we meet our mentor for the week, Dr Ivan Lam. Who coincidentally is our senior in Nanyang Junior College! How cool is that! We started out the day with an interesting introduction into the field of biological materials in MSE, how they actually improve the materials aspect in order to improve treatments etc. 

One interesting thing we learnt was in the field of cancer research. Cancer research is usually conducted on a 2D plane due to reasons like cost and convenience, yet cancer cells function in a 3D plane, thus it is necessary to come up with a method or structure to better understand how these cells function and device a method to actually cure cancer. Although a universal cure for cancer is a long process to work towards, due to the differential nature of cancer cells, it is possible to provide treatment for cancer for sure! Cancer cells are like 'survivors', they are able to grow and replicate outside the body as long as sufficient nutrients are provided for it to survive yet, it doesn't  need growth factors to grow!

We also learnt that cancer cells are context based, which is some thing I did not give much thought of.

Collagen is also a protein that we learnt more of today. These protein assist in fixing our superficial wounds. Furthermore, we learnt about the animals used in research. Mice are easy to breed and shares somewhat similar DNA as humans. However, the internal organs and skin of pigs closely resemble humans.

As our mentor completed his insightful introduction, he describes about cell culturing. We proceeded to the lab to learn more about cell culturing, preparation of samples and cell counting.

Our first hand view of the highly clean lab!

There is a special flask to contain the cells we are culturing. The flask contain ECM (extracellular matrix) which cause the cells they are dealing with to stick to the flask. The cells we used are quite cool; the cells originated from baby foreskin after their circumcision. The medium in the flask have to be favourable for cells. This means the right pH, growth proteins and nutrients.

Then, as for the culturing, our mentor withdrew the medium in the flask, washed each flask with PBS and added trypsin. PBS acts as a buffering medium and is isotonic as our cells, so that our cells will not have any net loss or gain in water. The trypsin acts to break the protein linkages on the ECM so that the cells can break free. In this case, the cells used are young and since it is from a baby, it has relatively long lifespan.

After that, the tubes containing the result is placed in a centrifuge machine to spin cause the cells to gather at the bottom of the tube. The solution is the removed and stored in the fridge to perform oxidative stress tomorrow to increase aging of the cell. Another sample is produced for staining.

We are introduced to various freezers. There is one in particular, which is the coolest there literally. The liquid nitrogen freezer reaching negative 180 degree Celsius.

We also performed a test to determine the cell concentration to determine how many cells are present in a milliliter. It is placed in a special film an observed under microscope.

Yes, YOU CAN ACTUALLY COUNT CELLS! :O

An average is determined from 4 squares. It cannot be determined accurately for the aged cells ;due to their sparse and low concentration.

The more numerous young cells and sparse old cells under the microscope!

DAY 5

Last day for this week!!

Time passed so fast, it was already day 5 of our programme. Despite the journey being arduous, it still felt fulfilling and fun. We learnt a lot about research and the things that are usually done in research.

For day 5, we had a lecture on some materials. We learnt that structure and microstructures are important as they gives the properties of the material. The direction of the fibres in a composite material determines at which direction the material can be pulled and withstand the force.

As for carbon, we learnt that the microstructures of the carbon determines the physical properties of the material. For example, diamond is hard due to the strong inter-carbon covalent forces. As for graphite, the layers bonded with weak van der waals forces allow different layer to slide over each other. It conducts electricity due to the free moving electrons. Fullerene is an interesting structure as it is used to provide volume for the material in question. We also get to know the various uses of materials in sports and military science.

After that, we went into a lab where we got to learn about carbon fibres and the strength of the fibre. The cloth like carbon fabric seemed so weak to me. The twines within the fabric were so easy to remove. However, we are shown this sample of a carbon fabric with resin matrix. And it looks like a magnificent, patterned black card. And upon close inspection, the material is very hard.

After that, we went to get to know about different computer programmes that are useful, such as modeling and animation softwares. It looks amazing and it feels like a sophisticated version, of Google sketchup.  We got to try and it looked really promising after I thought about the potential that it has to improve studies and research.

Testing underway!

DAY 4

Into the future!

We were introduced to ceramic composites in the morning, particularly in the defense application. Then our friendly researcher Dr Du Zehui presented us with a sample of composite that looked exceptionally smooth, well at least from our eyes. She then led us into a super secret room...

Opening the doors, we were surprised by a giant machine that looked like something out of a sci-fi film. 1 meter by 1 meter by 2.5 meter, is was an elaborate machine with probes, tubes and wires protruding out from the center. The machine, called a Scanning Electron Microscope (SEM), could view images of the material with a magnification of up to 120,000 times! Basically, you could see things far smaller than any conventional microscope can ever offer. After a little research, we learnt that the SEM works on the basis of shooting electrons rather than using light as used in a conventional microscope. Apparently, we were also told that the machine had to be located on the ground floor as any vibration from even the mere act or walking in the room could disturb the position of the sample.

On viewing the magnified sample, we were so surprised! There were so many scratches and protrusions on the surface on the material. It all seemed like a miracle, the work of science technology to bring us something so surreal. Later, we were told that the machine was not only a SEM, it is also able to coat the sample in a thin protective layer of platinum and even etch into the material with an ion beam to produce a cross-section of the sample. Amazing! Initially during the etching process, we could see the fibres embedded in the ceramic but then it was promptly defaced by the pure power of the high-speed bombarding ions.

After lunch, we met up with Dr Li Jianzhang who introduced us to the manufacturing procedure in making ceramic composites. He brought us around the laboratory where he worked to view the furnace used to temper the samples in order to harden the material and prepare it for its upcoming torture test. It can heat the samples to 1500°C! We were then shown a giant roll of carbon fibre used by the researchers in making ceramic fibre composites as well as several sample of composites from other researchers. We also had a brief discussion with him regarding the life of a research scientist where we gained new insights about his field of work.

Surface of the ceramic composite

Tiny particles on the surface of the material, high magnification!

 Minuscule flakes of silver on the ceramic with sizes for reference

Thin, protective layer of platinum deposited on the surface prior to etching

Microscopic particles of platinum!

 After etching with ion beam

After polishing

DAY 3

Foamation!


After allowing our foam to rest for about 20h, we are finally back at NTU, awaiting the fruits of our labour with anticipation. As our friend Daniel used the mallet to remove our foam from the mold, the floor shook with tremor, yet the foam remained sturdy and showed no signs of breaking. Apparently, this synthetic foam can withstand up to 100KN of force before it starts to fail! Thats like the weight of about 2 adult elephants! Its almost indestructible in our daily life.

As the workshops have been demolished to make way for a new workplace for students, we had to walk about 20 minutes to reach the laboratory where we could carry out our testing on the strength of our foam.
At the place, we placed our foam in the machine and allowed it to be compressed. Our 30% epoxy syntactic foam was being compressed into a flat piece! Yet the 20% and 10% ones were able to withstand a little more.

Next, we proceeded to the E-studio to learn how to plot the graphs of the force applied against its compressive strength and learned how to make sense of the data. It is very interesting to see the various graphs of the various materials and examine the various properties they have. As they say, a picture speaks a thousand words. So lets end of this post with some pictures :)

How our foam looked like after 20hours :)

Our group member with center parting, blogging in process!