The Department of Acoustics has knowledge about a vast variety of transducers of different sizes for use with both gasses and liquids. These transducers can be used as loudspeakers or microphones, as well as for energy harvesting. We have experience in selection and modelling of commercially available products, as well as in-house design of piezo-electrical (plastic or crystalline) and electrodynamical transducers (loudspeakers).
Sensor technology in the general area of technical acoustics involves applications where the sound signal is not necessarily audible. The sensors detect or generate acceleration, speed, deflection, or pressure for a specific application in a given medium.
Intimate knowledge about the mechanisms that generate the phenomena that are being measured, as well as a thorough understanding of the medium or material with respect to diffraction, absorption, noise sources, and coupling to the sensor or other materials; all this is required for an optimal design of a sensor, together with basic competency in transducer technology. The fact that these factors show a frequency dependency complicates matters further. The department has tools for modelling of transducers. We also have access to lab facilities at the Department of Electronics and Telecommunications at NTNU, enabling us to prototype our own transducer designs.
The department has experience in modelling and design of sensors from a number of different applications and a wide frequency range, spanning from a few hundred Hz up to several MHz. Examples of such applications are:
A multi-frequency system for detection of plankton in the sea
A sensor for measurements of sea currents
Sensors for analysis of metal melts
Sensors for detection of break-ins
Sensors for signalling in oil pipe walls
An acoustic fence for fish
A system for steering of fertilizer production aided by controlled sound
We also apply transducers for energy harvesting from different media. The energy is in turn used for powering of other sensors. An example of this is in gas pipes, where the energy in the gas flow can be harvested and used for signalling. Similarly, the kinetic energy of a fish can be exploited for signalling purposes. In both these cases the energy is stored in a battery or a capacitor.
Contact:
Tone Berg
Tel.: +47 73 59 20 22
