8 November 2010

Major advances for deep-sea space technology

An ultra-miniaturised submersible has been developed by scientists at the Ångström Space Technology Centre at Uppsala University. Great progress has now been made in developing the technology that the micro-submarine will take into the depths of the sea to show its surroundings there.

The submarine, which is no larger than a couple of beverage cans, is to be used for studies of subglacial lakes. It will initially be launched through narrow, kilometre-long bore holes for exploration of inaccessible environments in lakes below glaciers. In the long term, however, the technology should also be useful in marine archaeology or to investigate water pipes. The project is being implemented in cooperation with Mistra.

Scientists at the Ångström Space Technology Centre (ÅSTC) at Uppsala University have long been working to develop an ultra-miniaturised submersible. They have now made great progress in developing the technology to be taken by the craft into the deep to depict its surroundings.

World’s smallest sonar
In deep, dark water, either acoustic or optical technology was commonly used to take pictures. Scientists at the ÅSTC have developed the smallest sonar system in the world. A sonar device is an instrument that, using sound waves, receives information that can be converted into images. In this case the element itself, which is made to oscillate and generates the sound waves, is no larger than a match.

Tiny fish
The fact that the sonar unit is so small as to approach the size of the sound wavelength entails problems. It is, for example, hard to obtain sufficiently detailed images. To tackle this Jonas Jansson, a PhD student, has come up with a solution.
‘Now, using the sonar, I can even get images of tiny fish that in acoustic terms are almost water,’ says Jonsson in a press release.

The tiny submarine is also equipped with a camera. Here, too, the minimal size has posed challenges. The objects captured on camera lacked natural size and directional references. Martin Berglund, now a PhD student at the Department of Engineering Sciences, devised a solution to the problem within the scope of his degree project. He developed a measurement system using a diffractive lens with parts smaller than one-thousandth of a millimetre and a tiny laser, thereby obtaining an image that delineates the topography of the object depicted.

Mistra Mistra