We demonstrate a range of novel applications of micromachining and microelectromechanical systems (MEMS) for achieving efficient and tunable field emission devices (FEDs). Arrays of lateral field emission tips are fabricated with submicron spacing utilizing deep reactive ion etch (DRIE). Current densities above 150 A/cm/sup 2/ are achieved with over 150/spl middot/10/sup 6/ tips/cm/sup 2/. With sacrificial sidewall spacing, electrodes can be placed at arbitrarily close distances to reduce turn-on voltages. We further utilize MEMS actuators to laterally adjust electrode distances. To improve the integration capability of FEDs, we demonstrate batch bump-transfer of working lateral FEDs onto a quartz target substrate.