Day 10

Today is our last day at NTU~

Us with our mentor, Vipin.

Today, we spent most of the time experimenting microscope using different samples.

First, we used some microchips to examine under microscope. We learnt that if we see 2 different colors, it means that surface of the sample is not uniform.

Next, we used some insect as our sample. Below are the images we saw under the microscope!

 The wing and mouth are actually moving! The insect is still alive!

Let me prove you in the videos below!

  

 

 

Day 9

Our mentor was Vipin on the 9th day. He explained what material science and engineering is all about at the foundamental level. He called this "Material Tetrahydral" where there are 4 main points to keep in mind when you are talking about material research: Properties, Structure, Performances, Processing. That roughly ends up the introduction of material science and engineerings. He also told us about the 4 main steps to carry out a research, as illustrated in the diagram above.

 This is a picture generated by an optical microscope. The material used was Aluminium Oxide. Vipin taught us how to interpret the diagram.

This video basically showed the use of plasma in the coating of platinium on the sample. The purple gas was plasma.

Day 8

Us with our new mentor, Wen Bin! :)

This is dehydrated sol gel, the sample we are going to use today!

Heating the sample~

Since sol gel is semi-conductive, it has to be coated with platinum to be conductive so that it can be viewed under FESEM (Field Emission Scanning Electron Microscope). Coating only commences when the pressure becomes less than 5 Pa. But our experiment doesn't require such accuracy, so we started coating when the pressure is less than 7 Pa.

The sample after heating and coating!

Went to this room in F.A.C.T.S lab to view nano samples under FESEM

 FESEM! The room has to be kept dark so that images can be seen on the computer screen.

 Step 1: Take out

 Step 2: Put the sample in

 X-axis and Y-axis which rotate when focusing the image

FESEM! The electrons will be generated when 'HT button' on computer screen is clicked. They will then move down along the very long while color column shown in the picture and bombard with the atoms in the sample. These secondary electrons will then be deflected to the detector which helps to generate an image shown below!

This image was generated by a mechine called FESEM

The images can be sent to another computer as well!

Wen bin letting us try how to magnify and focus to get images shown above! It was so fun! :D

XRD machine

This is how it looks like inside!

Graph obtained from XRD machine~ Even if one doesn't really know what the compound is, this computer software will suggest lists of possible names. All you have to do is choose elements the sample contain and try to match the red lines with the peaks of your graph!

Cyclic Voltammetry set up!

Step 1: Connect wires only to the 2 electrodes in front

Step 2: Attach conducting metal to the brown color electrode & Put inside a solution to get ions

Step 3: Connect the wires to the brown color electrode behind

Step 4: Observe the color changes; colorless to dark blue and vice versa! Basically, this reversible reaction takes place: WO3 + electron + Li ion => LixWO3

Last but not least, we learnt about X-ray diffraction! This is the mechanism of some of the machines like FESM. Using this formula 2d x sin(theta)= n x lambda where d and lamda are fixed constants, the angle (theta) at which X-ray should be emitted can be calculated.

Chocolates wen bin gave us! So nice of him :)

Day 3

                                                      Us with our new mentor Kenji! :)

Unlike Wan Ling, Kenji is doing research on Inorganic materials. And the material we are going to use is Zince Oxide (ZnO)!
There are various ways such as electrotochemical deposition, hydro thermal, Chemical Solution method and Chemical Vapour Deposition (CVD) to synthesize ZnO. But we will be using CVD today!

Application : Photodector, X-ray detector

Went to F.A.C.T.S lab again to heat the samples first.

Went back to AMRC lab to carry out CVD! CVD takes place in the giant machine called horizontal tube furnace. Air inside must be pumped out first to optimize the atmosphere such that it contains only oxygen and Argon. Argon is a noble gas and hence is inert. Thus, it is used as a 'dummy' to move oxygen around.

Side view of the machine

Check this out! :D

Next, we took these chips samples to AFM lab to heat and viewed them under microscope. 



Day 7

A poster in AMR lab about Ferroelectric!

This mechine consists of a sharp tip that will be put scanning across the surface of the sample. When there is a scratch, it will be illustrated by a sharp increase in the graph as shown in the video. 

 

 AF Film Machine that can do characterisation, show how the surface of nano materials look like and measure the thickness up to nanometer! With this, we can know the properties of nano materials and put them into good use to benefit us!

There is a laser and this laser should reflect the light.

Monitor screen connected to AF Film Machine. Everything seen here is in nano meters. Even a small tip can be seen big here!

 During the experiment, the tip sticking out in the above picture will move to sense the height of the nano materials. 

How it looks like during the Experiment! 

DFL and LF should be more or less 0.00! It took a while for us to get this correct result! :D

Mini circuit on computer showing what's happening inside AF Film Machine!

Now, let's look at nano materials' surfaces!!

 Now let us look at the ferroelectric and dielectric graphs!

Finally we obtained a dielectric graph where two graphs lie on each other! Dielectric means having the property of transmitting electric force without conduction; insulating. 

Stay tuned! :)