  Long-term availability of minerals and industrial materials is a necessary
condition for sustainable development as they are the constituents of any
manufacturing product. In particular, technologies with increasing demand such
as GPUs and photovoltaic panels are made of critical raw materials. To enhance
the efficiency of material management, in this paper we make three main
contributions: first, we identify in the literature an emerging
computer-vision-enabled material monitoring technology which we call Material
Measurement Unit (MMU); second, we provide a survey of works relevant to the
development of MMUs; third, we describe a material stock monitoring sensor
network deploying multiple MMUs.
