Dragonfly wings inspire new generation of aerogels

LONDON: Scientists have created a new form of highlyefficient, low-cost insulation material based on the wings of a dragonfly. Aerogel is the most porous material known to man and ultralight, with a piece the size of a family car weighing less than a kilogramme, said Lidija Siller from the Newcastle University in the UK.

Starting out as a wet silica gel, similar in structure to jelly, the material is carefully dried to create a strong, porous material, said Siller, joint lead author of the research published in the journal Advanced Materials.

However, until now, removing the water molecules without collapsing the fine silica structure has been a long, difficult and expensive process and as a consequence, the use of aerogels has been limited to a few highly specialist tasks, such as the collection of stardust in space.

Now, a team of experts has managed to cheaply replicate the process by mimicking the way in which the dragonfly dries out its wings. Instead of drying the silica under high temperature and pressure, the team used bicarbonate of soda to ‘blow’ out the water molecules, trapping carbon dioxide gas in the pores. PARIS: Scientists have for the first time set eyes on a three-dimensional Neanderthal brain in the for m of a virtual model made to fit the empty, fossilised skulls of long-dead individuals, a study said on Thursday.

The reconstructed organ confirmed earlier observations, based more loosely on head size and shape, that Neanderthals had a larger brain than their early Homo sapiens cousins, but with a smaller cerebellum — the lower part near the spine that controls balance and movement. It is also involved in speech and learning.

The distinction may have caused s o c i a l a n d c o g n i t ive d i f f e r e n c e s between the near relatives, and may explain why one went extinct while the other thrived, said Naomichi Ogihara of the Keio University in Japan, who co-authored a study in the jour nal Scientific Reports.

“Although the difference could be subtle, such a subtle difference may become significant in terms of natural selection,” he said. But nothing can be concluded yet about any relation between the Neanderthal’s brain organisation and its eventual demise.

Ogihara and a team combined the disciplines of physical anthropology, mechanical engineering, and neuroscience for their reconstruction.

They used virtual casts to model the shape and size of four fossilised Neanderthal skull cavities, and four of ancient humans. They then used MRI scans from nearly 1,200 modern-day people to model an “average” human brain, which they “deformed” to fit into the prehistoric skulls.

This allowed the team to estimate what the brains would have looked like, and how individual regions would have differed between the two species.

“We are so far from understanding the brain of prehistoric humans that any small advance is welcome,” French palaeoanthropologist Antoine Balzeau said. He was not involved in the research. Neanderthals emerged in Europe, Central Asia and the Middle East some 200,000 years ago. They vanished about 30,000 years ago — coinciding roughly with the arrival of modern humans out of Africa.

NEANDERTHALS EMERGED IN EUROPE, CENTRAL ASIA AND THE MIDDLE EAST SOME 200,000 YEARS AGO.