Measurements of Anisotropic (Off‐Axis) Friction‐Induced Motion

A new 3D sensor-actuator attachment for a Surface Forces Apparatus (SFA) allows measurements of friction forces between surfaces in all 3 orthogonal directions. The anisotropic friction forces when shearing two mica surfaces separated by a nanometer-thin film of hexadecane can induce complex transient and steady-state motions involving displacements perpendicular to the applied force and nonzero velocity at all stages of back-and-forth sliding. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.