Power Optimization of TENGs via Load Capacitance Sizing
Maryam Hosseini1, Mahmood Chahari2, Milutin Stanacevic1
1Department of Electrical and Computer Engineering, Stony Brook University (SUNY), Stony Brook, NY 11794 USA.
IEEE Sensors Journal
|April 9, 2026
Summary
Optimizing load capacitor size in triboelectric nanogenerators (TENGs) with full wave rectifiers (FWRs) maximizes power output. This simple strategy enhances energy harvesting efficiency without extra circuits.
Area of Science:
- Energy Harvesting
- Materials Science
- Electrical Engineering
Background:
- Triboelectric nanogenerators (TENGs) are promising for harvesting ambient mechanical energy.
- Efficient power delivery from TENGs, especially those using AC output with full wave rectifiers (FWRs), requires careful impedance matching.
- Optimizing load capacitance is crucial for maximizing power transfer and minimizing system response time.
Purpose of the Study:
- To develop a power optimization strategy for TENGs by tuning the load capacitor size in an FWR.
- To identify the optimal load capacitance that maximizes power delivery and minimizes the time to reach steady-state power.
- To validate the effectiveness of capacitor sizing as a sole optimization method.
Main Methods:
- Cycle-level analysis of input voltage, current, and rectifier turn-on time during mechanical motion.
- Identification of optimal load capacitance through theoretical analysis and experimental validation.
- Testing with a vertical contact-separation TENG with varying internal capacitance (24pF–96pF) and rectifier capacitance (390pF).
Main Results:
- An optimal rectifier capacitance of 390pF was identified, achieving maximum power delivery (900nW at 1.7Hz, 2.7μW at 5Hz) within the second cycle.
- Suboptimal capacitances either failed to reach peak power or significantly delayed the steady state.
- Sensitivity analysis showed robustness, with ±30% capacitance variation maintaining ≥90% of peak power.
Conclusions:
- Load capacitor optimization is an effective strategy for maximizing power in TENGs with FWRs.
- This method achieves peak power delivery solely through capacitor sizing, simplifying system design.
- The proposed strategy offers flexibility and robustness for practical implementation in energy harvesting systems.
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