An item such as a fabric-based item or other item may have one or more actuators. An actuator may have a conductive strand of material. A control circuit may supply a current to the conductive strand that induces a length change in the conductive strand due to ohmic heating and associated thermal expansion effects. The control circuit may be used to activate the actuator in response to user input that is supplied to an associated input device such as a switch, capacitive sensor, force sensor, light-based sensor, or other input component. The fabric-based item may include fabric such as woven fabric or knit fabric. Strands of conductive material may serve as signals paths for supplying current to conductive strands in actuators. Magnetic-field-based actuators may be formed by coiling conductive strands around tubular support structures such as piping in fabric-based items.