Floating Microdisks Rotated by Molecular Motors

A possibility of utilization of molecular motors for creation of unidirectional rotation of tiny disks floating on a surface is considered theoretically. The bottom side of the disk is covered with grafted motors combined with flat blades submerges into a viscous liquid for torque generation. When exposes to UV-light, the motors start to rotate all in the same direction, and they transfer their rotation to the blades creating a mechanical torque that turns the disk. The disk angular velocity scales as omega similar to omega L/R where omega is motor angular velocity, L is the length of the oars, R is the micro-disk size. A competition between directional ballistic-type rotation and rotative diffusion is considered. The setup can be used for evaluation of the primary motor parameters: the motor rotation speed omega = 2 pi f, and the maximum motor torque load M-max.