Researchers from the University of Cambridge have created a new method of forming complex shapes and found that the development of form in nature can be stimulated by the physical properties of the materials in contrast to earlier findings that suggested otherwise. This discovery could help scientists create complex structures from simple building blocks and be used in various applications including pharmaceuticals, painting, cosmetics and household products.
The researchers inserted droplets of oil into a soapy water solution which was then slowly frozen. Over time, the researchers found that "plastic crystal phases" stemming from dissolution formed on the inside surfaces of the oil droplets and caused them to shape-shift into various shapes such as hexagons, octahedrons and triangles.
"There are many ways that non-biological things take shape," Stoyan Smoukov, who led the research, said in a press release. "But the question is what drives the process and how to control it - and what are the links between the process in the biological and the non-biological world?"
The new study proposes an answer to the question of what drives this process, which is referred to by scientists as morphogenesis. In animals, morphogenesis is the driver of cell distribution during embryonic development and also plays a part in the formation of tumor cells in animals. Smoukov's research shows that the slow freezing of oil droplets in a soapy solution can lead to the shape-shifting of the droplets as well as a return to their original form if the solution is re-warmed. Furthermore, this process was found to be driven by the self-assembly of a plastic crystal phase that was observed forming underneath the surface of the droplets.
"The phenomenon is so rich in combining several active areas of research that this study may open up new avenues for research in soft matter and materials science," said Slavka Tcholakova, co-author of the study.
"If we're going to build artificial structures with the same sort of control and complexity as biological systems, we need to develop efficient bottom-up processes to create building blocks of various shapes, which can then be used to make more complicated structures," said Smoukov. "But it's curious to observe such life-like behavior in a non-living thing - in many cases, artificial objects can look more 'alive' than living ones."
The findings were published in the Dec. 9 issue of Nature.
