We present the research status of a deformable mirror made of a magnetic
liquid whose surface is actuated by a triangular array of small current
carrying coils. We demonstrate that the mirror can correct a 11 microns low
order aberrated wavefront to a residual RMS wavefront error 0.05 microns.
Recent developments show that these deformable mirrors can reach a frequency
response of several hundred hertz. A new method for linearizing the response of
these mirrors is also presented.Comment: To appear in "Ground-based and Airborne Instrumentation for Astronomy
II" SPIE conference, Marseille, 23-28 June 200