Long silicon nanowire yarns with length up to 12 mm were fabricated from aligned silicon nanowires with crystal silicon cores
of bifurcation structures as well as entangled amorphous hairy silicon oxide, which played vital roles in the formation of
the yarns, and the silicon nanowire yarns were used as a pH sensor with the sensitivity of 1,080 ± 31 nS/pH in the pH range
of 2–12.