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Abstract The mechano‐electrical properties of poly(3‐hexylthiophene) thin films are investigated as a function of their tie‐chain content. Tie chains play an indispensable role in enabling strain‐induced structural alignment and charge‐transport enhancement in the strain direction. In the absence of sufficient tie chains, the external mechanical force cannot induce any significant polymer backbone alignment locally or crystallite reorientation at the mesoscale. These samples instead undergo brittle fracture on deformation, with cracks forming normal to the direction of strain; charge transport in this direction is hindered as a consequence. This mechanistic insight on strain alignment points to the promise of leveraging tie‐chain fraction as a practical tuning knob for effecting the mechano‐electrical properties in conjugated polymer systems.
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3D printed architected conducting polymer hydrogels
Conducting polymer hydrogels combine electrical conductivity and tunable water content, rendering them strong candidates for a range of applications including biosensors, cell culture platforms, and energy storage devices. However, these hydrogels are mechanically brittle and prone to damage, prohibiting their use in emerging applications involving dynamic movement and large mechanical deformation. Here, we demonstrate that applying the concept of architecture to conducting polymer hydrogels can circumvent these impediments. A stereolithography 3D printing method is developed to successfully fabricate such hydrogels in complex lattice structures. The resulting hydrogels exhibit elastic compressibility, high fracture strain, enhanced cycling stability, and damage-tolerant properties despite their chemical composition being identical to their brittle, solid counterparts. Furthermore, concentrating the deformation to the 3D geometry, rather than polymer microstructure, effectively decouples the mechanical and electrical properties of the hydrogel lattices from their intrinsic properties associated with their chemical composition. The confluence of these new physical properties for conducting polymer hydrogels opens broad opportunities for a myriad of dynamic applications.
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- Award ID(s):
- 1945664
- PAR ID:
- 10415486
- Date Published:
- Journal Name:
- Journal of Materials Chemistry B
- Volume:
- 9
- Issue:
- 35
- ISSN:
- 2050-750X
- Page Range / eLocation ID:
- 7258 to 7270
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d1tb00877c
