“The shape-memory phenomenon is common in nature,” said Professor Ying Diao, “but we are not really sure about nature’s design rules at the molecular level.”
Apparently, the shape memory mechanism in synthetic organic material was discovered accidentally. “We looked at single crystals under a microscope and found the transformation process is dramatically different than we expected,” said researcher Hyunjoong Chung. “We saw concerted movement of a whole layer of molecules sweeping through the crystal that seem to drive the shape-memory effect – something that is rarely observed in organic crystals and is therefore largely unexplored.”
This led the team to explore the merger between shape-memory materials and organic electronics. “Today’s electronics are dependent on transistors to switch on and off, which is a very energy-intensive process,” Prof Diao said. “If we can use the shape-memory effect in plastic semiconductors to modulate electronic properties in a cooperative manner, it would require very low energy input, potentially contributing to advancements in low-power and more efficient electronics.”
The team is currently using heat to demonstrate the shape-memory effect, but is also experimenting with light, electrical fields and mechanical force, as well as ‘tweaking’ the molecular structure of materials. “We have already found that changing just one atom in a molecule can significantly alter the phenomenon,” Chung said.
