Extended Data Fig. 10: Scaling of the rotational friction coefficient with the size of the rotating object.
Left, centre and right panels show theoretical dependences of the rotational drag coefficients of a sphere, of a rod and of a DNA molecule rotating about its axis, respectively. Theoretical expressions for the spherical and rod-like objects are provided in Methods. For a DNA load, the drag coefficient per basepair was taken to be 1.23 degrees ns–1 pN–1 nm–1, a value extracted from the all-atom MD simulations presented in Fig. 2d. The purple star in the middle panel depicts the friction coefficient extracted from our all-atom MD simulation of a DNA duplex pressed against a graphene surface (see Extended Data Fig. 7 for details) after accounting for the difference between the simulated and experimental viscosity values.
