Deformable mirror using magnetic membranes: application to adaptive optics in astrophysics

An alternative approach to more compact deformable mirrors for adaptive optics is developed. A thin and flexible reflective membrane is coated with a magnetic layer and locally deformed by the field created by an array of planar microcoils. This novel technology should enable higher resolution with smaller, lighter integrated mirrors. Several complementary modelling tools are used to study the electromagnetic, mechanical, magneto-mechanical and thermal behaviour of the device. A first prototype of O 30 mm mirror with a matrix of permanent magnets and an array of 25 microcoils is under construction.