Actuation by electrostatic repulsion by nonvolatile charge injection

In this paper a novel actuation scheme through electrostatic repulsive-force generated by nonvolatile charge injection is proposed and demonstrated. Nonvolatile charge injection is achieved by integrating MEMS devices with electrically erasable programmable read only memory (EEPROM) structures. Repulsive force of ∼0.2 μN is observed across a 3 μm gap with poly-silicon beams of 360 μm in length. Larger actuation force can be achieved with smaller gap. A capacitor network model is also proposed to analyze the charge injection and distribution in such systems. This actuation scheme holds promises in achieving large-tuning-range varactors, dynamically tunable mechanical resonators, and wear-free hinges, etc.