  We report the fabrication and measurements of ionic liquid gated Hall bar
devices prepared on thin Ca$_3$Ru$_2$O$_7$ flakes exfoliated from bulk single
crystals that were grown by a floating zone method. Two types of devices with
their electrical transport properties dominated by $c$-axis transport in Type A
or that of the in-plane in Type B devices, were prepared. Bulk physical
phenomena, including a magnetic transition near 56 K, a structural and
metal-insulator transition at a slightly lower temperature, as well as the
emergence of a highly unusual metallic state as the temperature is further
lowered, were found in both types of devices. However, the Shubnikov-de Haas
oscillations were found in Type A but not Type B devices, most likely due to
enhanced disorder on the flake surface. Finally, the ionic liquid gating of a
Type B device revealed a shift in critical temperature of the structural and
metal-insulator transitions, suggesting that such transitions can be tuned by
the electric field effect.
