Stretchable and self-healable semiconductors are in high demand for wearable and implantable devices. However, conjugated polymers (CPs), known for their rigid and coplanar backbone and high crystallinity essential for effective charge transport, are typically rigid and brittle. Recently, the fabrication of CP/elastomer composites through physical blending has emerged as a simple but highly efficient and promising strategy for developing stretchable semiconductors. Additionally, introducing hydrogen bonding (H-bonding) crosslinks can further enhance the stretchability and self-healing capabilities of these materials while depressing phase separation of incompatible polymers. In this work, we incorporated H-bonding crosslinks into elastomer phase, developing an extremely soft (E ~1.6 MPa), stretchable (COS ~1500%), and self-healable (self-heal within 5 mins) semiconducting composite diketopyrrolopyrrole/amide-polyisobutylene (DPP-T/PIB-A). The composite also exhibited blending ratio-independent charge mobility of ~0.09 cm² V^-1 s^-1 and stable electrical property upon cyclic stretching. Morphological study indicated the elastomer domain accommodated most of the strain upon stretching, allowing the electronic active CP fibril phase to remain intact, thereby explaining the stable charge carrier mobility. Furthermore, we also introduced H-bonding crosslink to both components of CP/elastomer composites. With the different H-bonding location sites, the morphology and stretchability of the composites was well controlled. This work provides new direction to develop highly healable and electronically stable semiconductive composite and offers valuable insights for the future design of stretchable CP/elastomer composites.

Angela Awada

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