  The kinetic inductance detector (KID) is a versatile and scalable detector
technology with a wide range of applications. These superconducting detectors
offer significant advantages: simple and robust fabrication, intrinsic
multiplexing that will allow thousands of detectors to be read out with a
single microwave line, and simple and low cost room temperature electronics.
These strengths make KIDs especially attractive for HEP science via mm-wave
cosmological studies. Examples of these potential cosmological observations
include studying cosmic acceleration (Dark Energy) through measurements of the
kinetic Sunyaev-Zeldovich effect, precision cosmology through ultra-deep
measurements of small-scale CMB anisotropy, and mm-wave spectroscopy to map out
the distribution of cosmological structure at the largest scales and highest
redshifts. The principal technical challenge for these kinds of projects is the
successful deployment of large-scale high-density focal planes -- a need that
can be addressed by KID technology. In this paper, we present an overview of
microstrip-coupled KIDs for use in mm-wave observations and outline the
research and development needed to advance this class of technology and enable
these upcoming large-scale experiments.
