Integrating charge mobility, stability and stretchability within conjugated polymer films for stretchable multifunctional sensors

Sung Yun Son; Giwon Lee; Hongyu Wang; Stephanie Samson; Qingshan Wei; Yong Zhu; Wei You

doi:10.1038/s41467-022-30361-0

Integrating charge mobility, stability and stretchability within conjugated polymer films for stretchable multifunctional sensors

Nat Commun. 2022 May 18;13(1):2739. doi: 10.1038/s41467-022-30361-0.

Authors

Sung Yun Son^#^{1

2}, Giwon Lee^#^{3

4}, Hongyu Wang⁴, Stephanie Samson⁵, Qingshan Wei⁶, Yong Zhu⁷, Wei You⁸

Affiliations

¹ Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
² Department of Chemistry, Kwangwoon University, Seoul, 01897, Republic of Korea.
³ Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
⁴ Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
⁵ Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
⁶ Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA. qwei3@ncsu.edu.
⁷ Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, 27695, USA. yzhu7@ncsu.edu.
⁸ Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA. wyou@unc.edu.

^# Contributed equally.

Abstract

Conjugated polymers (CPs) are promising semiconductors for intrinsically stretchable electronic devices. Ideally, such CPs should exhibit high charge mobility, excellent stability, and high stretchability. However, converging all these desirable properties in CPs has not been achieved via molecular design and/or device engineering. This work details the design, synthesis and characterization of a random polythiophene (RP-T50) containing ~50 mol% of thiophene units with a thermocleavable tertiary ester side chain and ~50 mol% of unsubstituted thiophene units, which, upon thermocleavage of alkyl chains, shows significant improvement of charge mobility and stability. Thermal annealing a RP-T50 film coated on a stretchable polydimethylsiloxane substrate spontaneously generates wrinkling in the polymer film, which effectively enhances the stretchability of the polymer film. The wrinkled RP-T50-based stretchable sensors can effectively detect humidity, ethanol, temperature and light even under 50% uniaxial and 30% biaxial strains. Our discoveries offer new design rationale of strategically applying CPs to intrinsically stretchable electronic systems.

Abstract

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