The use of bolometric interferometry to measure polarization B-modes in the CMB was proposed for a series of projects leading up to QUBIC. The Millimeter-wave Bolometric Interferometry (MBI) began in 2002 leading up to the prototype MBI-4 operating in Wisconsin in 2008/09 which measured fringes with bolometric interferometry. In Europe, the Background RAdiation INterferometer (BRAIN) was developped and installed at the Dome-C research area at the South Pole. There were three campaigns with BRAIN in 2006, 2007, and 2011. Members of these collaborations joined together in 2008 to develop the Q & U Bolometric Interferometer for Cosmology (QUBIC).
The QUBIC Technological Demonstrator was assembled at the APC lab in Paris, and underwent a series of test campaigns from 2018 through 2020. This prototype will be sent to Salta, Argentina, close to the observing site at Alto Chorillos. After a commissioning period at the lab in Salta, the QUBIC-TD will be sent to the observing site and observations of the sky will begin in 2022. During 2023, the Technological Demonstrator will be upgraded to the Full Instrument with two observing frequency bands and 2048 TES bolometers in the two focal planes.