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EURAXESS
NEWS17 Feb 2021NewsFundingPhD

PhD grants : Low-power converter dedicated to capacitive ultrasonic energy harvesters: application to ultrasonic-based wireless power transmission (EMSTU)

university_de_tours

DEADLINE: 15th April 2021

Description

  • 36 months doctoral funding (October 2021 to September 2024)
  • Keywords

High efficiency converter, cMUT transducer, piezoelectric generator, energy harvesting

  • Profile ans skills required

The candidate must hold a Master's of Research degree or an engineering degree in one of the following specialties:

 

- Engineering Sciences with specialization in Electronics

 

- Engineering Sciences with specialization in Electrical Engineering

 

During his/her curriculum, the candidate will have had experience in

electronics, acoustics, signal processing and instrumentation. A good

knowledge of this field is essential to the success of the proposed

work. Complementary competence in one of the following areas would be

greatly appreciated:

 

- Software experience: PSpice or LTSpice; Matlab or Scilab; Octave

 

- Experience in instrumentation

  • Project description

Capacitive Micro-machined Ultrasonic Transducers (cMUT) are

micro-capacitors (typically 50x50 µm2), one electrode of which is mobile

and the other fixed. When this capacitor is polarized and receives an

ultrasonic wave, the received mechanical energy is converted into

electrostatic energy. If a high number of micro-capacitors (typically a

few hundred) are combined in parallel, then the amount of energy

harvested is likely to be able to power electronic devices with very low

consumption. This area is commonly referred to as AET for Acoustic

Energy Transfer. This energy transfer, performed at ultrasonic

frequencies, can be done classically over a distance of a few

centimeters in biological tissues. AET thus appears to be a promising

avenue for powering Implanted Medical Devices (IMDs).

 

The electrostatic energy recovered by the cMUT receiver still needs

to be converted to a form suitable for the targeted electronic load.

This results in precise specifications in terms of shape and level of

voltage and current. An electronic converter must therefore be

interposed between the harvester and the load, and must have very low

power consumption. In addition, the cMUTs must be polarized by a DC

voltage at the beginning of the cycle, so a power source of a few µJ is

required to start operation. For this initial energy, one approach

consists of integrating a composite piezoelectric layer (here based on

ZnO nanowires) on the membrane of the cMUT.

 

In the framework of this thesis, the aim is to propose original

low-power conversion structures dedicated to cMUTs used for the

conversion of energy from ultrasonic waves in the range [40 kHz, 400

kHz]. Among the possible tracks, non-linear converters of SECE

(Synchronous Electric Charge Extraction) type, initially designed for

piezoelectric harvesters, also give good performances on electrostatic

harvesters. In addition, Totem-pole converters allow the voltage to be

raised in a similar way to SECE type converters, but with the advantage

of better efficiency by replacing the rectifier stage with the switching

cell. Particular care will be taken in the development of the control

electronics, which will have to be ultra low power consumption.

  • References

1] G. V. B. Cochran et al., “Piezoelectric internal fixation

devices: A new approach to electrical augmentation of osteogenesis,” J.

Orthop. Res., vol. 3, no. 4, pp. 508–513, 1985.

 

[2] S. Ozeri et al., “Ultrasonic transcutaneous energy transfer using

a continuous wave 650 kHz Gaussian shaded transmitter,” Ultrasonics,

vol. 50, no. 7, pp. 666–674, 2010

 

[3] G. Poulin-Vittrant et al., “Challenges of low-temperature

synthesized ZnO nanostructures and their integration into nano-systems,”

Materials Science in Semiconductor Processing 91 (2019) 404-408

 

[4] EnSO, “Energy for Smart Objects,” financement ECSEL-JU 2016-2020, http://enso-ecsel.eu/

 

[5] S. Boisseau et al., “Microstructures électrostatiques de

récupération d’énergie vibratoire pour les microsystèmes,” Techniques de

l'ingénieur Innovations en énergie et environnement, RE160, 10 octobre

2010

 

[6] A. Morel et al., “A unified N-SECE strategy for highly coupled

piezoelectric energy scavengers,” Smart Materials and Structures, IOP

Publishing, 2018, 27 (8), pp.4002

 

[7] M. Perez et al., “Triboelectret-based aeroelastic flutter energy

harvesters,” Journal of Physics: Conference Series 773 (2016) 012021

 

[8] S. Jacques, C. Reymond, J.-C. Le Bunetel and G. Benabdelaziz,

'Comparison of the power balance in a Totem-Pole Bridgeless PFC topology

with several inrush current limiting strategies', Journal of Electrical

Engineering 72 (2021)

To apply, click here

 

 

 

Disclaimer:

 

The responsibility for the funding offers published on this

website, including the funding description, lies entirely with the

publishing institutions. The application is handled uniquely by the

employer, who is also fully responsible for the recruitment and

selection processes.