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Project Description

Electrical interfaces

In order to provide efficient energy extraction from mechanical source, dedicated interfaces has been developed by the BESTMEMS consortium.

 

Synchronous inversion and charge extraction

More precisely, an original strategy developed in the framework of the project consisting in increasing the voltage output of the piezoelectric element before extraction, yielding a much better harvested energy. This concept, called SICE for " Synchronous Inversion and Charge Extraction" is depicted below:

 

Circuit implementation and operations are shown through the following animation:

 

Compared to typical interfaces, this permits a significant harvested power boosting effect while ensuring a harvested energy that is independent from the connected electrical device:

 

More information in this paper.

 

Synchronized Switch Harvesting on Oscillator

Once of the issues in implementing nonlinear circuits lies in the size of the inductance, even if the latter is already reduced compared to linear approaches. One of the achievement done in BESTMEMS was to demonstrate that a secondary piezoelectric element can advantageously replace this inductance, by using the motional motion that can stores mechanical energy.

More information in this paper.

 

Integration

First batch of integration of the previous two aproaches have been sucessfully tested.

 

References

  1. M. Lallart, W.-J. Wu, L. Yan and S.-W. Hung, “Inductorless Synchronized Switch Harvesting using a Piezoelectric Oscillator”, IEEE Trans. Power Electronics, Vol. 35(3), pp. 2585-2594, 2020.
  2. K.-R. Cheng, H.-S. Chen, M. Lallart and W.-J. Wu, “A 0.25μm HV-CMOS Synchronous Inversion and Charge Extraction (SICE) Interface Circuit for Piezoelectric Energy Harvesting”, 2018 IEEE International Symposium on Circuits and Systems (ISCAS), Florence, Italy, May 27-30 2018.
  3. M. Lallart, L. Yan, W.-J. Wu and Y. Hsieh, “Efficient Electrical Interface Based on Synchronized Voltage Inversion and Energy Extraction for Piezoelectric Electrical Generators”, 12th Energy Harvesting Workshop, Falls Church, VA, Sept. 11-14 2017 (invited)
  4. M. Lallart, W.-J. Wu, Y. Hsieh and L. Yan, “Synchronous Inversion and Charge Extraction (SICE): a Hybrid Switching Interface for Efficient Vibrational Energy Harvesting”, Smart Mater. Struct., Vol. 26(11), 115012, 2017.