  This white paper suggests posing a "grand challenge" to the HEP
instrumentation community, i.e. the aggressive development of additive
manufacturing, also known as 3D-printing, for the production of particle
detectors in collaboration with industry. This notion is an outcome of
discussions within the instrumentation frontier group during the 2013 APS-DPF
Snowmass summer study conducted by the U.S. HEP community. Improvements of
current industrial 3D-printing capabilities by one to two orders of magnitude
in terms of printing resolution, speed, and object size together with
developing the ability to print composite materials could enable the production
of any desired 3D detector structure directly from a digital model. Current
industrial 3D-printing capabilities are briefly reviewed and contrasted with
capabilities desired for printing detectors for particle physics, with
micro-pattern gaseous detectors used as a first example. A significant impact
on industrial technology could be expected if HEP were to partner with industry
in taking on such a challenge.
