Reversing Polarity

Now the question was can we get a custom sugar object maker that reverses heat to cool?

Extending from the previous question; sugar objects are a fascinating material that can be liquid, amorphous, and solid. This means that according to the very factors including heat, can affect their phases at which they stand and this makes their properties and textures differ/look tremendously. From this, a simple heat increase and decrease can facilitate their phase changes that are unique in their material and visibly express. This extends the question to: Can we showcase all three phases of sugar object, hands-free, on this micro-heater by manipulating its thermoelectrical energy?

Y Axis = Heat flow; The temperature criteria for glass transition

The Three Phases of an Amorphous Solid [10]

Went through multiple trials to enable such a notion:

I mainly tried out the solutions based on the components available at the lab :) In chronological order below:

1

Using MOSFET Transistors

MOSFET transistors can be used to switch the polarity of the voltage applied to a Peltier module, allowing for rapid temperature control in heating and cooling applications. But, I needed to use two for each polarity swap, and the transistors become hot very fast. It was deployable using heatsinks, however.

2

Using DPDT Relays

DPDT relays help polarity reversal in a Peltier module by mechanically switching the connections, toggling between heating and cooling modes. However, the immediate switching could potentially break the module and the timed delays did not seem to solve the problem. I had to find an alternative at this point and order the more well-known solution.

3

Using H-Bridge Drivers

H-Bridge drivers, like relays, are used for precise control of electronic switching--used for robot motors and directional changes. It has been the most effective and working after trials. With this, I hooked up thermocouples and allowed a PID control for an accurate and safer polarity switching.

References:

[9] Chen, Y., Zhang, H., & Cheng, S. (2006). Quantification of crystallinity in substantially amorphous materials by synchrotron X-ray powder diffractometry. Pharmaceutical Research, 23(6), 1235-1243. https://doi.org/10.1007/s11095-005-7626-9

[10] Britannica, T. Editors of Encyclopaedia. (n.d.). Amorphous solid. In Encyclopedia Britannica. Retrieved October 30, 2024, from https://www.britannica.com/science/amorphous-solid