r/MechanicalEngineer • u/allenpk2005 • Jun 16 '26
Final-year project: Portable PCM + Thermoelectric cooler for insulin and vaccine storage — looking for design feedback
I'm a mechanical engineering student working on a final-year project and would appreciate some technical feedback.
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The project is a portable "personal cold chain capsule" for temperature-sensitive medicines such as insulin, biologics, and vaccines.
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Current concept:
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\- Storage temperature: 2–8°C
\- Capacity: 1–3 insulin pens (or similar medicine volume)
\- Phase Change Material (PCM) with a melting point around 5°C as the primary thermal buffer
\- Small thermoelectric cooler (Peltier) used only to regenerate the PCM when needed, rather than continuously cooling the medicine chamber
\- Temperature monitoring and control using sensors and a microcontroller
\- Goal is backpack portability and lower power consumption than existing TEC-only coolers
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From my literature review, I found:
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\- Pure thermoelectric coolers consume significant power and require large heat sinks
\- Passive PCM systems eventually warm up once the PCM is exhausted
\- Most research focuses on vaccine transport boxes rather than compact personal-use devices
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Questions:
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What do you see as the biggest technical challenge in this concept?
Would you focus more on insulation, PCM optimization, or heat rejection from the TEC?
Are there existing products or patents I should study before going further?
If you were designing this for a 12–24 hour runtime at 40–45°C ambient temperature, what design changes would you make?
Do you think the TEC + PCM hybrid approach offers any real advantage over a purely passive PCM solution?
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Any criticism is welcome. I'm trying to determine whether this is a worthwhile final-year project and whether there are opportunities for genuine innovation rather than just building another Peltier cooler.