Percolation by brush architecture: A pathway towards soft electronics

Achieving tissue-mimetic mechanics and electrical conductivity in a single molecular system remains challenging, as stretchable electronics often trade mechanical compliance for electronic performance. We address this problem by applying a computation-guided design to synthesize polydimethylsiloxane (PDMS) bottlebrush graft copolymers with precisely tuned fractions of poly(3-hexylthiophene) (P3HT) side chains. The P3HT grafts serve dual roles as physical crosslinks between bottlebrush strands and as conductive pathways. Solution-cast thin films exhibit percolated networks of needle-like P3HT crystals, confirmed by transmission electron microscopy, small-angle X-ray scattering, and simulations. These films combine low elastic moduli (≈1–100 kPa) with electrical conductivities up to ≈10⁻² S cm⁻¹. Such graft copolymer-based materials combining tissue-like mechanics with robust electronic functions offer promising platforms for design and manufacture of wearable and implantable devices.