Sunsensor miniaturization where is the end?

Sunsensors are used for the attitude control of satellites. The common sensors use either the cosine dependence of the photo current or the sensing of a centroid movement for a spot which is created by positioning a pinhole at a known distance above a position sensitive detector. Recent research initiated by the Dutch Microned program has lead to significant reduction in size without impairing the performance. This research will lead to fully autonomous sensors which are produced using micro-system technologies with associated size reductions of at least a factor of 30 but possibly two orders of magnitude.