This talk will begin with a presentation of the general science case for infrared astrometry. Focussing on the special case of the Galactic centre, I will review the proposed Small-JASMINE infrared astrometry mission and discuss its scientific and technological challenges. The state of the art and possible developments in the fields of CMOS detectors and cooling are identified as crucial issues for future astrometry missions in the infrared. The GaiaNIR technology proposal is presented as a way forward regarding the CMOS detectors.