A gap-closing electrostatic actuator with a linear extended range

We present for the first time a gap-closing electrostatic actuator with a linear extended range. We achieve this by designing a nonlinear spring which exactly counteracts the nonlinear effects of electrostatic attraction forces in gap-closing actuators. We demonstrate this on test devices with an initial gap of g=22μ. The initial response up to a deflection of g/4 is stable and is inevitably nonlinear, but beyond this point we demonstrate good linearity up to a displacement of 85% of the nominal gap.