Storage-layer-based nonvolatile memory (NVM) devices, such as Flash, ferroelectric RAM, or magnetic RAM, have limited reliability at high temperature (HT, T > 200 °C). On the contrary, storage-layer-free NVM devices based on a bistable nanoelectromechanical (NEM) mechanism and adhesion forces show excellent reliability at HT. This letter presents design optimization of an electrostatic NEM NVM device. The set/reset principle is based on the pulsed-mode switching of a mechanically free electrode (the shuttle), which is placed inside a guiding pod, having two stable positions. Based on the shuttle kinematic equation, this letter derives key design and operation parameters, particularly optimization in terms of switching speed and switching energy. The small footprint of the shuttle NEM NVM makes it applicable to ultracompact and reliable data storage at HT. © 2012 IEEE.