Rotary motion devices (10) are provided. In one embodiment, the rotary motion devices (10) may comprise: a mass (12); a circumferential component (14); a plurality of spokes (16) connecting the mass (12) to the circumferential component (14), at least one of the spokes (16) comprising an electroactive polymer, wherein: the at least one spoke (16) has at least one input electrode and is configured to deflect upon application of an electrical potential across the at least one input electrode, and the rotary motion device (10) is configured such that deflection of the at least one spoke (16) causes the mass (12) to move, thereby causing the rotary motion device (10) to become off balance with respect to gravity, and rotate.