According to an example, a three-dimensional (3D) printed material may include a body formed of a non-conductive material. Additionally, conductive channels, sensing devices, and signal emitters may be embedded within the body. The sensing device may be in electrical communication with the conductive channel such that the sensing device is affected by interruption of the current applied through the conductive channel. Additionally, the signal emitter may emit a wireless signal in response to the sensing device being affected by interruption of the applied current.