Rarefied gas dynamics is a branch of fluid mechanics that studies gas flows under conditions when the mean free path of molecules is large in comparison with the characteristic dimension. Referred to as Superaerodynamics until 1960s, the field was initially shaped by problems arising in atmospheric flight at high altitudes. Rarefied flow analysis is now employed in areas as diverse as study of asteroid impacts and manufacturing of bio/pharmaceuticals. In this talk, we will review several emerging applications of rarefied gas dynamics, in particular, in the areas of micro/nanofabrication, MEMS and micropropulsion. The performance of conventional fluidic devices such as pumps, combustors and rocket engines is dramatically decreased at the microscale, mostly due to increased viscous and heat transfer losses. However, high-performance unconventional devices can be engineered by exploiting the new physics arising at nano/microscale due to interaction between non-equilibrium gases on one hand and electrostatics, surface tension in liquids and thermal transport in solids on the other. Examples include current work on experimental and computational demonstration of Knudsen force actuation by thermoelectric heating for novel MEMS sensors and actuators; efficient thermal valving at the microscale using film-evaporation concept for thermal control and propulsion of picosats and microplasma generation due to field emission in MEMS structures under low-voltage GHz fields.