An international team of researchers developed a stretchable semiconducting polymer that could lead to electronic skin that mimics real skin.

The polymer can heal when damaged by use of intermolecular hydrogen bonds that can be repeatedly broken and reformed. The material could serve as the base for wearable electronics that need to flex, stretch, and endure mechanical abuse.

Available polymer-nanowire composites are flexible but lack adequate charge transport functionality. A molecular design approach was pursued to fabricate a semiconducting polymer that is stretchable but also has high charge-transport ability, or carrier mobility.

Stretchable organic transistor array on hand. Credit: Zhenan BaoNanometer-scale cracks that form in the polymer after repeated drastic stretching are easily repaired by heating the material in the presence of chloroform vapors, after which the material almost completely recovers its electronic properties.

Monomers of 2,6-pyridine dicarboxamide) were added to the semiconducting polymer 3,6-di(thiophen-2-yl)- 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (or DPP), resulting polymer with semiconducting crystalline DPP units, which transport charge.

The material was used to construct high-performance field-effect transistors that have a charge mobility of 1.3 cm²/V/s. The polymer retains a mobility of over 1 cm²/V/s and the transistor’s performance does not change even after it is stretched and released 500 times by a quarter of its length, which is typical of most practical applications.

Researchers from Cambridge University (UK), Stanford University (U.S.), Asahi Kasei Corp. (Japan), SLAC National Accelerator Laboratory (U.S.), and Samsung Advanced Institute of Technology (South Korea) contributed to this development.