Polymer printing adapted for better electrical conductivity

The team led by chemical and biomolecular engineers report their findings in Science Advances.

According to Illinois, conjugated polymers are formed by the combination of electron-rich molecules along a backbone of alternating single and double chemical bonds. The conjunction allows electricity to be conducted efficiently through a polymer, making it highly desirable for use in electrical and optical applications.

This mode of transporting charges works so well that conjugated polymers are now poised to compete with silicon materials, the researchers said. However, these polymers can contort into spirals when they form, which severely impedes charge transport.

"The flatness or planarity of a conjugated polymer plays a large role in its ability to conduct electricity," said chemical and biomolecular engineering professor Ying Diao, who led the study. "Even a slight twist of the backbone can substantially hinder the ability of the electrons to delocalise and flow."

It is possible to flatten conjugated polymers by applying an enormous amount of pressure or by manipulating their molecular structure, but both techniques are very labour-intensive, Diao said in statement. "There really is no easy way to do this."