A deployable device includes a tape-spring capable of passing from a wound configuration about a first axis Z to a deployed configuration along a second axis X substantially perpendicular to the first axis Z, the tape-spring having two characteristic dimensions, a first characteristic dimension being the width of the tape-spring along the first axis Z, a second characteristic dimension being the thickness of the tape-spring along a third axis Y substantially perpendicular to the first axis Z and to the second axis X. At least one of the two characteristic dimensions has a non-constant value along the second axis X.