Scientists are heading to Greenland this week to trial new sensors that will be placed under its ice sheet – and the shell for the devices was made in Flint Cross.

The 'Cryoeggs' will give an insight into the behaviour of meltwaters beneath the ice.

Leading the work is Dr Liz Bagshaw from the School of Earth and Ocean Sciences at Cardiff University.

For the past 10 years Dr Bagshaw has been developing tiny wireless sensors that can gather measurements from more than 2,000 metres inside a glacier, while at the same time withstanding the extreme conditions.

"Scientists have traditionally sent sensors down to the bottom of glaciers on extremely long and flexible cables," said Dr Bagshaw.

"The problem is that if you leave them there for long enough to get accurate readings over a longer time scale, the movement of the glacier ends up snapping the cables. That's why we need wireless sensors."

The initial prototypes developed by Dr Bagshaw and colleagues were made from Christmas baubles, which provided a perfect shell from which the case of the sensors could be moulded.

The technology has been scaled up to the size of a grapefruit and includes a tiny circuit board within a mould that can measure the pressure, electrical conductivity and temperature of the surrounding meltwater.

The individual measurements that the sensors collect are very simple - however, combined they provide the team with a detailed picture of the conditions underneath the glacier.

The project relies on the wireless transmission of the data, but finding the right frequency is key.

"We find that VHF radio signals - slightly higher than those used for FM radio - are the best to use as they have a low enough frequency to penetrate the ice," said Dr Mike Prior-Jones, from the School of Earth and Ocean Sciences.

Dave Finch - of DGF Engineering Ltd, based off the A505 in Flint Cross - told the Crow: "It has been a pleasure and a privilege working with Dr Prior-Jones and being part of this exciting project manufacturing the Cryoegg shell.

"Everyone at DGF Engineering Ltd wishes Dr Bagshaw and Dr Prior-Jones every success in Greenland this month and in obtaining all the data in the coming year."