User wearable interface device having force feedback

An interface device comprising:

• a body which is attachable to a part of user's body;
• a power supply which has one end portion coupled to the body and supplies power;
• and
• a grip which is movable by the power received from the power supply,
• wherein the grip is movable in a first direction and a second direction with respect to the body, and the first direction may not be parallel with the second direction,
• wherein the power supply includes:
• a power unit which generates rotational force;
• and
• a clutch unit which transfers the rotational force received from the power unit to the grip, and
• wherein the power supply selectively implements any one state of:
• a no-load state where the power unit and the grip are physically coupled through the clutch unit;
• a load state where the power unit and the grip are physically coupled through the clutch unit, and the rotational force of the power unit is transferred to the grip;
• and
• a freewheeling state where the power unit and the grip are physically uncoupled through the clutch unit,
• wherein the resistance module controls formation or release of physical coupling between the power unit and the grip through the clutch unit, and
• wherein the power supply controls generation or extinction of rotational force which can be transferred to the grip through the power unit, and selectively implement any one state of the no-load state, the load state, and the freewheeling state of the grip by selectively combining the formation and release of the physical coupling through the resistance module and the generation and extinction of the rotational force through the power supply.