Electrostatic Bending Actuators (NED)

Nanoscopic Electrostatic Drive (NED)

V-NED actuator
© Fraunhofer IPMS
V-NED: Allows vertical deflections (out of the chip plane)

The novel MEMS-based bending actuators developed at Fraunhofer IPMS have the following features:

  • V-NED: Enables vertical deflections (out of the chip plane).
  • L-NED: Enables lateral deflections (within the chip plane)
  • CMOS compatibility: Enables integration of bending actuators, sensors and electronics within a semiconductor device
  • RoHS compatibility: Enables RoHS compliant bending actuators and provides an alternative to functional ceramics currently exempt from RoHS


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.

Degrees of freedom of movement

  • 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.

L-NED actuator

L-NED: Allows lateral deflections (within the chip level)

In collaboration with

Brandenburg University of Technology Cottbus-Senftenberg, BTU (Department of Micro- and Nanosystems)


Sponsored by

Federal Ministry of Education and Research BMBF and Ministry of Science, Research and Culture MWFK of the State of Brandenburg