Autonomous inspection of a surface topology of an airfoil of a gas turbine engine

An autonomous device for inspecting surface topology of an airfoil of a gas turbine engine, the autonomous device comprising:

• a base;
• means for coupling the base to the airfoil in a manner that permits movement of the base across the airfoil while remaining coupled thereto;
• means for moving the base across the airfoil while remaining coupled thereto;
• a tactile gel sensor extending from the base to the airfoil when the base is coupled thereto, the tactile gel sensor including:
• a flexible optical gel having nominally planar opposite surfaces defining a nominal gel thickness extending over an image area;
• a lighting element configured to illuminate the flexible optical gel from an end surface between the nominally planar opposite surfaces flexible optical gel;
• a plurality of airfoil contacting members extending between one of the nominally planar opposite surfaces of the flexible optical gel and the airfoil when the base is coupled thereto, thereby distorting the flexible optical gel in response to changes in the surface topology of the airfoil;
• and
• a two-dimensional imager that images the flexible optical gel over the image area, thereby capturing two-dimensional images;
• and
• a surface topology calculator attached to the base and electrically connected tactile gel sensor and configured to locate defects in the surface topology of the airfoil based on the two-dimensional images captured by the two-dimensional imager.