To provide a hydraulic actuator having sufficient durability in a case in which high pressure is applied such as a case in which oil pressure driving is adopted. The hydraulic actuator includes a sealing mechanism (200). A tube (110) is inserted into a body portion (211) of a sealing member (210). A first locking ring (220) locks a sleeve (120) at an outer side of the body portion (211) in the radial direction D.sub.R and at a position adjacent to a flange portion (212). A caulking member (230) caulks the tube (110), the sleeve (120) located at the outer side of the tube in the radial direction D.sub.R, a first folded portion (120a) in conjunction with the sealing member (210).

The device (1) takes up the basic structure and operation of the McKibben type artificial muscles and similar, in which is provided a hollow cylindrical chamber (2), of resilient material, which is inflated in the active phase (K). The chamber (2) interacts with a braided sleeve (3), consisting of threads (31, 32), almost inextensible, arranged in crossed helical paths having a characteristic angle of inclination with respect to the longitudinal axis (X) of the device (1). The sleeve (3) is connected at the ends with two rigid head members (4A, 4B) provided to be mechanically connected to external bodies. The invention provides adjusting means (5), associated to said rigid head members (4A, 4B) adapted to vary their distance (D) at rest, so as to require a proportional and consistent change in the angle of inclination : if the latter is exactly 54.7, the device (1), in the active phase (K) stiffens without dimensional changes, if the angle is greater an axial extension is obtained, if the angle is smaller an axial contraction is obtained.

The present invention relates to a soft actuator moving linearly against external stimuli whose expansion and contraction can be actively controlled, suggesting that the actuator of the invention overcomes the problems of the conventional soft actuators, The soft actuator of the present invention can be repetitively driven quickly and accurately by controlling heating and cooling by using thermoelectric effect and, the soft actuator of the present invention can realize bending, tensioning, compression, and rotational driving of a tubular device containing a driver.

A soft buckling linear actuator is described, including: a plurality of substantially parallel bucklable, elastic structural components each having its longest dimension along a first axis; and a plurality of secondary structural components each disposed between and bridging two adjacent bucklable, elastic structural components; wherein every two adjacent bucklable, elastic structural components and the secondary structural components in-between define a layer comprising a plurality of cells each capable of being connected with a fluid inflation or deflation source; the secondary structural components from two adjacent layers are not aligned along a second axis perpendicular to the first axis; and the secondary structural components are configured not to buckle, the bucklable, elastic structural components are configured to buckle along the second axis to generate a linear force, upon the inflation or deflation of the cells. Methods of actuation using the same are also described.

An apparatus for use in actuating a wearable terminal device includes a housing coupled to a harness system, a control unit, a movable actuating element having its one end in the housing and the other end connected through coupling means to the terminal device, and a conduit which contains the actuating element. The actuating element is a body-powered cable, an artificial tendon coupled to an actuator device installed in the housing, or an actuator wire made of smart material.

An orthotic device is disclosed. The orthotic device may be adapted to be inserted into a shoe to enable the foot to replicate normal motion so that the user regains substantially normal operation of the foot. The orthotic device may have a frame system formed of a lightweight supportive material and configured to extend along at least the bottom of the user's foot, and an electronically actuated muscle operatively connected to the frame system for expanding and contracting at predetermined levels to adjust the inclination of the user's foot and mimic movement of the foot, when functioning normally. The orthotic device may also have a controller operatively connected to the muscle for transmitting signals corresponding to the predetermined levels to the muscle, and a sensor controlled by the user for actuating the muscle.

The present foot prosthesis includes various structural features that provide the foot with advantageous rollover properties. In certain embodiments, the foot guides rollover toward the medial side. For example, an asymmetrical upper element and a correspondingly shaped resilient ankle member support more of the wearer's weight on the lateral side as the foot rolls over. In another embodiment, stiffeners added to the resilient ankle member increase the stiffness on the lateral side relative to the medial side. In certain other embodiments, the foot provides progressively increasing support from mid stance through toe off. For example, a gap between the resilient ankle member and the lower element closes during the later portion of the wearer's gait. The closing gap increases a contact area between the resilient ankle member and the lower element, providing progressively increasing support. In another embodiment, the foot includes a gap between a lower front edge of an attachment adapter and the upper element. The gap may be filled with a resilient material.

Provided herein is an artificial muscle capable of being miniaturized, realizing precision movement, and performing selective relaxation/contraction deformation according to the power output necessary in the muscle, the muscle including a first operation unit that includes electro-active polymer where relaxation-deformation occurs based on electric energy being applied; a heating unit that generates heat energy based on the electric being applied; a second operation unit that has a yarn structure and where contraction-deformation occurs based on the heat energy generated in the heating unit; and a control unit that applies electric energy to the first operation unit and the heating unit.

In some embodiments, the present invention is directed to an actuator which includes at least the following: a pre-stretched electro-active polymer film being pre-stretched in a single or biaxial planar directions; at least one first semi-stiff conductor attached to a first surface of the pre-stretched electro-active polymer film, wherein the first surface is parallel to the single or biaxial planar stretch directions; at least one second semi-stiff conductor attached to a second surface of the pre-stretched electro-active polymer film, wherein the second surface is opposite to the first surface; where the semi-stiff conductors are configured to: fix the pre-stretched electro-active polymer film in a pre-stretched state and allow the pre-stretched electro-active polymer film to expand; a pair of mechanical connectors coupled to each end of an active region of the pre-stretched electro-active polymer film.

An orthotic device is disclosed. The orthotic device may be adapted to be attached to a limb to enable the limb to replicate normal motion so that the user regains substantially normal operation of the limb. The orthotic device may have a frame system formed of a lightweight supportive material and configured to receive the user's limb, and an electronically actuated muscle operatively connected to the frame system for expanding and contracting at predetermined levels to mimic movement of the limb, when functioning normally. The orthotic device may also have a controller operatively connected to the muscle for transmitting signals corresponding to the predetermined levels to the muscle, and a sensor controlled by the user for actuating the muscle.