= Solution
\b[<friction force microscopy> is suitable.] Contact scanning twists the <AFM cantilever>; the lateral photodetector difference measures <friction> and can distinguish the supported <graphene> and <glass> even if their heights are close. Acquire both trace and retrace and use half their lateral-signal difference to suppress slope-induced cross-talk. Keep the normal load low enough to avoid dragging or damaging the flake, control humidity and contamination, and calibrate torsional sensitivity if a quantitative <coefficient of friction> is required. An electrical connection is unnecessary.
Back to article page
