Electrostatic Bending Actuators (NED)

Through up to 200 nm thin electrode gaps, enormously high forces of electrostatic fields are generated with the help of a control voltage. These forces are in turn transformed into lateral forces by means of suitable topographies (V-NED) or geometries (L-NED) and lead to a curvature of bending beams:

• NEDs are: MEMS bending actuators that have a mode of operation comparable to bimorph actuators (piezoelectric or thermomechanical effects). They are fabricated in surface micromechanics (V-NED) or bulk micromechanics (L-NED) on or in silicon substrates.
  
• Novelty: Due to the drive principle, the deflection of the NED actuators is much larger than the electrode gap. Therefore, large deflections can be generated with low control voltages. Our vision is: to make enormously small electrode gaps and the associated enormously high forces of electrostatic fields accessible for electrostatic actuators.
• NED actuators can be operated: quasi-static, resonant but also digital - i.e. with discrete deflection states.

• Curvature: The cylindrical curvature of the NED actuators can create a deflection of the free end of the beam. Instead of a simple beam shape, the NED actuator can be designed as a rotationally symmetrical plate. This results in an actuator plate that curves spherically.
• Bidirectional: Suitable electrode topographies or geometries can be used to deflect the actuators in a positive or a negative direction. A combination of topographies or geometries or an arrangement of the actuator cells on both surfaces of the bending actuator allows movements in both directions (bidirectional).
• Tilting and linear motion: A simple tilting motion can be generated by two mechanically coupled NED actuators. If several NED actuator pairs are connected in a suitable way, linear movements are possible.