This paper covers the problems faced by current production methods for MEMS sensors, in particular the difficulty of ramping up production to meet the ever-increasing demand for sensors. It then discusses the challenges of the solution of building MEMS using only standard CMOS processes in a fab and how they have been solved by Nanusens using techniques that are now patent pending. The focus of this paper is on linear inertial sensors as a worked example of how these techniques can be used. Further papers will explore their use for other types of sensors that can also be built using CMOS and, crucially, simultaneously on the same die at the same time.