We were finally granted permission to go to lab, though only maximum 2 per group, to start working on our projects. Though we did not have all the materials that we ordered yet, we decided to still make a trip down to the M&T Lab to look at the materials and resources available in the lab and perhaps carry out a mini trial of our planned technique (TEC/Peltier method)? Since we were no longer living in halls due to the Circuit Breaker, we had to travel all the way from home (cries). However, it was a chance to finally get out of the house so Dan Hong and Shuchi volunteered to go down to the lab.

It was nice to see a few friends at the lab and have a little chit chat with them about how they have been doing and what their project was about. We also got to look around the lab and look at the available resources that we could use. One of them were parts from a project done 3 years ago! Tony also had a few water cooling blocks and TEC modules that we could use.

Since we had a water cooling block, TEC modules and other relevant parts, we decided to carry out a little trial to test how well a single TEC would work to form ice.

We set up our system first by using heatsink made by a student during M&T previously and connected it to a power supply. The lowest temperature reached was about 4 degrees Celsius, which was not low enough to freeze water.

Then we tried setting up a TEC module attached to a water cooling block using thermal tape available in the lab. We also attached a pump to one of the pipes attached to the water cooling block to facilitate movement of water. We supply 5V to the water pump and 12V to TEC module. The TEC was still not reaching a temperature of below 0 degrees so we increased voltage to 14V which then resulted in a drop to -0.9 degrees Celsius. However, we realised that the thermal tape we used may not have been ideal or efficient (perhaps due to low quality, since it was only $10 per roll, compared to the usual $300).

Hence, in our final experiment round, we removed the thermal tape and used no form of adhesive or heat conducting paste as an attachment for TEC module and water cooling block. We pushed down one side of the TEC to ensure contact and used the same voltage supply as the initial round (5V & 12V). This time it was a semi success as the water did start to freeze, but not very well. We then increased voltage supply to TEC to 13V and water on the surface of TEC froze in 3 minutes! The video below shows our set up and partially frozen water on the TEC module.

 

In the 2-3 hours we spent in the lab, we got to experiment a little and plan ahead for our next session. This one session was not sufficient to determine how well the TEC would work with our current setup and power supply. Additionally, since freezing will not be done directly on the TEC module, we will have to further experiment with an aluminium/brass/copper container attached to the cold side of TEC module and see if freezing still occurs. Moreover, with some of the ordered supplies arriving (eg. thermal paste, more TEC modules), we could experiment more.