Tribo-electric/electret (Nano) Generator TENG)

"Understanding and improving the efficiency of TENGs"

Grants:  Univ Gustave Eiffel

Modeling
Device
Conditioning circuit with micro-plasma switch
Publications

Modeling

In addition to the model proposed by  Niu et al, we have proposed a lumped model directly inspired from the  traditional electret Kinetic Energy Harvester. This model is suitable for PSpice and can easily take into account practical specifications of the TENG for accurate conditioning circuit simulations.
 

V_TE is a constant voltage source representing the charge trapped in the the triboelectret layer. It is independant from the mobile electrode position and from the load. It can be directly measured with an electrostatic contactless volmeter, or, if the layer is not accessible, using an electrical technique we have developped in purpose.

C_TENG is the capacitance measured accross the TENG terminals. It  can be obtained  by measuring the phase shift in an RC circuit.

In this work, we have also modelized the effect of the mechanical contact.
 
  

Device

We have devlopped a simple flexible and progressive triboelectric nanogenerator based on macro-triangle-prism-shaped conductive polyurethane (PU) foam and polytetrafluoroethylene (PTFE) film. The proposed macro-structured conductive PU foam also integrates the functions of spring, spacer and electrode. Thanks to the innovative structures and choice of the materials, an extended current pulse width is obtained. 
 

Conditioning circuit with micro-plasma switch

Rectification with stable charge pumps

We have shown that a half-wave (HW) rectifier performs much better than a full-wave (FW) diode bridge after a few conversion cycles. Indeed, during the early cycles, the output voltage of the FW rectifiers increases with twice the slope of the HW, although in that case both powers are far from the optimum of each circuit. However, if the output voltage of the rectifier can be set to half of its saturation voltage, HW outperforms the FW by a factor (C_{TENG_max}/C_{TENG_min}+1)/2.

Rectification with unstable charge pumps

We have proposed to use the Bennet doubler with TENGs. This is a new class of conditioning circuit inspired from the electrical machines of the 18th century. It is also made of diodes and capacitors only. These circuits have the ability to exponentially increase the charge on the TENG's electrodes during operation and so to increase its bias and conversion efficiency. A minimum value of  C_{TENG_max}/C_{TENG_min} is necessary, which is typically 2 for the most simple architecture, but it can vary depending on the circuit configuration.
 
  

High-voltage power management using a plasma switch

Electrostatic energy harvesters need a high bias, which for TENGs is brought by an efficient triboelectric contact and/or thanks to the voltage boost from an unstable charge pumps. However, for most applications it is necessary to convert the output to a low voltage around a few volts. This can be obtained using a Buck DC-DC converter, but its switch needs to be controlled at a voltage close to the high bias value. We proposed to use a MEMS micro-plasma switch to self-control the charge transfer through a Buck circuit at high voltages. By adjusting the MEMS switch design, we can control its hysteresis in order to continuously maintain a high-bias on the transducer and hence maximize the energy conversion.

  
This work has been highlighted in the  Electronics Insights Blog of the Electropages website.

Related publications

Modeling of TENGs

• “Understanding and Modeling of Triboelectric-Electret Nanogenerator”, R. Hinchet, A. Ghaffarinejad, Y. Lu, J. Y. Hasani, S.-W. Kim et P. Basset,  Nano Energy, vol. 47, pp. 401-409, 2018
• “A conditioning circuit with exponential enhancement of output energy for triboelectic nanogenrator”, A. Ghaffarinejad, J. Yavand Hasani, R. Hinchet, Y. Lu, H. Zhang, A. Karami, D. Galayko, S.-W. Kim and P. Basset, Nano Energy, vol. 51, pp. 173 – 184, 2018

Flexible TENG

• “Progressive Contact-separate Triboelectric Nanogenerator Based on Conductive Polyurethane Foam Regulated with a Bennet Doubler Conditioning Circuit”, H. Zhang, Y. Lu, A. Ghaffarinejad and P. Basset, Nano Energy, vol. 51, pp. 10-18, 2018

Conditioning circuits for TENGs

• “Employing a MEMS plasma switch for conditioning high-voltage kinetic energy harvesters”, H. Zhang, F. Marty, X. Xia, Y. Zi, T. Bourouina, D. Galayko and P. Basset, Nature Communications, vol. 11, no. 1, p. 3221, 2020

• “An Inductor-Free Output Multiplier for Power Promotion and Management of Triboelectric Nanogenerators toward Self-Powered Systems”, X. Xia, H. Wang, P. Basset, Y. Zhu, Y. Zi, ACS Applied Materials & Interfaces, Feb 5;12(5):5892-5900, 2020
• “Superior performance of half-wave to full-wave rectifier as a power conditioning circuit for Triboelectric nanogenerators”, A. Ghaffarinejad, J. Y. Hasani, D. Galayko, P. Basset, Nano Energy, Volume 66, 104137, 2019
  

• “A conditioning circuit with exponential enhancement of output energy for triboelectic nanogenrator”, A. Ghaffarinejad, J. Yavand Hasani, R. Hinchet, Y. Lu, H. Zhang, A. Karami, D. Galayko, S.-W. Kim and P. Basset, Nano Energy, vol. 51, pp. 173 – 184, 201

Maintained by Webmaster