Broadband vibration energy harvesting for wireless sensor node power supply in train container

Area of Science:

• Energy Harvesting
• Materials Science
• Logistics Technology

Background:

• Wireless sensor nodes (WSNs) are crucial for temperature and humidity monitoring in cold chain logistics.
• Sustainable self-power supply for WSNs is essential, with energy harvesting technology being a key solution.
• Low amplitude, broadband vibration energy harvesting is critical for train applications.

Purpose of the Study:

• To design and simulate piezoelectric vibration energy harvesters (PVEHs) for WSNs in cold chain logistics.
• To achieve low resonant frequencies and high electromechanical sensitivity for effective energy harvesting.
• To enhance broadband vibration energy harvesting performance for practical train applications.

Main Methods:

• Design and simulation of two PVEHs using COMSOL with L-shaped mass blocks.
• Implementation of stoppers and series connection for broadband energy harvesting.
• Experimental validation of PVEH performance under varying accelerations and frequencies.

Main Results:

• PVEH-1 and PVEH-2 achieved maximum powers of 0.24 mW and 0.1 mW at resonant frequencies of 13.1 Hz and 18.8 Hz, respectively (at 0.5 m/s² acceleration).
• The series circuit style demonstrated a wider operating frequency bandwidth and reduced charging time compared to the independent style.
• Two PVEHs in series effectively powered a temperature and humidity WSN within the 8.7-22.0 Hz broadband frequency range (at 3.0 m/s² acceleration, >5 V RMS).

Conclusions:

• The developed PVEHs, particularly in series configuration, provide a viable solution for sustainable power supply to WSNs in cold chain logistics.
• The L-shaped mass blocks and series connection effectively address the need for low-frequency, broadband vibration energy harvesting.
• This energy harvesting scheme shows significant promise for application in cold chain logistics train containers, ensuring continuous monitoring.