Figure 5. Moisture-driven liquid crystal cellulose engine.

(a) Schematic of the motor, showing location of moist air and rotation direction. The alignment direction is parallel to the axes of the wheels. The free surface of the film is on the outer side. (b) Series of video frames showing rotation. (Movie of the motor is available under supplementary materials.) The motor is housed in a dry environment. Momentum transfer from the moist air is small, and opposes the observed motion. Belt dimensions are: 1.0 cm × 8.0 cm × 30 μm; wheel dia. is 14 mm. The direction of rotation is indicated by a black arrow, and of moist air flow by a white arrow (a). In (b), t = 2 s/frame.