Acoustic Energy Transfer

Involved People
Maurice RoesPhD student
dr. J.L. DuarteCo-promotor
ir. M.A.M. HendrixCo-promotor
Prof. dr. E.A. Lomonova, M.Sc.First promotor

There are many situations in which electrical contact between systems is impractical or to be avoided altogether. In such cases it is possible to use Contactless Energy Transfer (CET) to power an electrical device over a distance. One can think of charging mobile device batteries, cars, or biomedical implants. Furthermore, CET is often used in linear and planar actuators where the wear of cable slabs, and the parasitic force that they exert are undesired.

The transfer of energy between two points is accomplished in most CET systems by the use of magnetically coupled inductors. There are, however, situations in which there are drawbacks to inductively coupled CET, e.g., when there is a large air gap in comparison to the transmitter and receiver diameter, or when the use of electromagnetic fields is not allowed.

A solution to overcome these drawbacks is to use sound waves to transfer energy. This method lends itself perfectly for transferring energy over intermediate distances (centimeters to meters) at relatively low power levels (milliwatts to Watts). The benefit of acoustic energy transfer (AET) is that it is possible to use transducers that are much smaller than this distance while still achieving a high energy transfer efficiency. Alternatively, if the desired transmitter and receiver dimensions are given —as is usually the case— then the frequency that is used in an AET system can be much lower than that of the EM system, while still achieving a comparable directionality. Accordingly, losses in the driving power electronics
will be much lower. The design of the electronics can be kept considerably simpler as well. On another note, AET is ideally suited in situations where no EM fields are allowed, and high directionality of the power transfer in combination with small system dimensions is required.

The project will focus on the investigation of the feasibility of AET, its merits and the inherent problems. A number of demonstrators will be built as a proof of concept.