Fig. 4: Torque-speed measurement.
From: An optically driven microstructure for torque measurement in rotary molecular motors
a Angle as a function of time when the laser power is alternated between Pr = 0.14 (unshaded area) and a test power P (shaded area). Whenever the power is switched back to P, ϕ starts from a `random' value, which is obtained by when the light-mill is rotated rapidly backward. b Time and angle averaged velocities as a function of P. Averages are computed only over the data points belonging to the shaded areas in (a). The dashed green line plots the expected curve for a constant motor torque as in Fig. 3e. c Torque-speed curve obtained starting from the angle averaged velocity \(\overline{\omega }\) in (b). Horizontal line is the torque Tfree measured before the light-mill is attached, while the shaded area represents its confidence interval
