To search for the possible existence of half quantum vortices in chiral p-wave superconductors, we fabricate Sr2RuO4-based superconducting quantum interference devices from bulk crystals using a focused ion beam process. The transport properties measured below 1.5K show the presence of supercurrent in weak link bridges, and the switchings of the bridges to the finite voltage states against the increment of the bias current exhibit complex responses. Expected modulation of the critical current in an applied magnetic field has not been detected at present.