A slider is provided for actively controlling a fly height of the slider relative to a data storage disc during operation of a data storage system. The slider includes a slider body having front and back surfaces, a length and a crown curvature on the front surface along the length. The slider also includes first and second elongated rails which are positioned on the front surface along the length of the slider body and form first and second bearing surfaces. Each bearing surface includes a leading portion, a trailing portion and a waist portion, wherein the waist portion is wider than the leading and trailing portions and has a maximum width within a middle half of the length of the slider body. A deformable material is positioned on the slider body having a dimension that is changeable in response to an electrical control signal applied in a deformable material, wherein a change in the dimension causes a change in the crown curvature.