Disclosed herein is an electromagnetic flow sensor device for monitoring flow of fluid in a channel. The sensor device includes a first electrode to be disposed along the channel and in communication with the fluid, a second electrode to be disposed along the channel and in communication with the fluid, and a radially expandable frame to structurally support the first electrode and the second electrode while conforming to the channel to position the first electrode and the second electrode along the channel. The device may also include an antenna coupled to the first and second electrodes to wirelessly provide an indication of a voltage induced between the first and second electrodes. In some embodiments, the radially expandable frame includes an insulating link such that the first and second electrodes are not electrically connected via the radially expandable frame. The sensor device may also include a structure having an inductance coupled to the first and second electrodes to wirelessly provide an indication of the induced voltage.