  We demonstrate the active tuning of all-dielectric metasurfaces exhibiting
high-quality factor (high-Q) resonances. The active control is provided by
embedding the asymmetric silicon meta-atoms with liquid crystals, which allows
the relative index of refraction to be controlled through heating. It is found
that high quality factor resonances ($Q=270\pm30$) can be tuned over more than
three resonance widths. Our results demonstrate the feasibility of using
all-dielectric metasurfaces to construct tunable narrow-band filters.
