Abstract: A device includes a tube and a sleeve configured to at least partially encircle a portion the tube along its length. The tube is flexible and airtight and defines a longitudinal axis along a center of the tube, and is configured to bend along the longitudinal axis upon at least partial evacuation of the tube to form a joint. The joint defines a joint angle relative to the longitudinal axis, thereby approximating a revolute joint with torsional stiffness. Actuating a joint includes partially evacuating a flexible tube defining a longitudinal axis, thereby forming a bend in the tube at an angle with respect to the longitudinal axis at a perimeter of a rigid sleeve at least partially encircling the tube, and restoring a neutral pressure to the tube, thereby removing the bend in the tube.

Abstract: Systems and methods for a wearable “exo-shell” to improve the gait of elderly people during obstacle avoidance tasks are disclosed. With payload and energy expenditure as a main focus of this design, the present system leverages switchable, passive systems, in combination with lightweight materials that minimize additional metabolic costs, while remaining as “transparent” to the user as possible when inactive.

Abstract: A device includes a tube and a sleeve configured to at least partially encircle a portion the tube along its length. The tube is flexible and airtight and defines a longitudinal axis along a center of the tube, and is configured to bend along the longitudinal axis upon at least partial evacuation of the tube to form a joint. The joint defines a joint angle relative to the longitudinal axis, thereby approximating a revolute joint with torsional stiffness. Actuating a joint includes partially evacuating a flexible tube defining a longitudinal axis, thereby forming a bend in the tube at an angle with respect to the longitudinal axis at a perimeter of a rigid sleeve at least partially encircling the tube, and restoring a neutral pressure to the tube, thereby removing the bend in the tube.

Abstract: A mechanical system includes a curved beam and a motor coupled to the curved beam. The curved beam is configured to buckle at two different locations along the positive and negative portions of its load/displacement curve, corresponding to opposite and equal sense bending directions. The motor is configured to impart a flapping motion to the curved beam.

Abstract: Various embodiments for a foldable quad-rotor (FQR) inspired by an origami mechanism are disclosed herein. The FQR can fold its arms during flight to enable aggressive turning maneuvers and operations in cluttered environments. A dynamic model of folding is built for this system with the collected data, and a feedback controller is designed to control the position and orientation of the FQR. Lyapunov stability analysis is conducted to show that the system is stable during arm folding and extension, and motion planning of the FQR is achieved based on a modified minimum-snap trajectory generation method.

Abstract: A hydrogel precursor composition includes 10 wt % to 40 wt % N-isopropylacrylamide, 0.5 wt % to 2 wt % N,N?-methylenebisacrylamide, a solvent, and a photoinitiator. The hydrogel precursor composition is photocurable and thermally responsive. A thermally responsive hydrogel is formed by photopolymerizing the hydrogel precursor composition. The thermally responsive hydrogel may be used to mimic the activity of muscle fibers.

Abstract: Various embodiments of a foldable unmanned aerial vehicle having a multi-layer laminate structure and extendible arms are disclosed.

Abstract: In one aspect, a device for providing propulsion in water is provided by the present disclosure. The device includes a parallel mechanism including at least five rigid bars and at least five joints, each joint being positioned between two of the rigid bars and configured to allow movement of the at least five rigid bars, a first servo motor coupled to a first rigid bar included in the at least five rigid bars, a second servo motor coupled to a second rigid bar included in the at least five rigid bars, and a controller coupled to the first servo motor and the second servo motor and configured to actuate the first servo motor and the second servo motor according to a predetermined pattern.

Abstract: A hydrogel precursor composition includes 10 wt % to 40 wt % N-isopropylacrylamide, 0.5 wt % to 2 wt % N,N?-methylenebisacrylamide, a solvent, and a photoinitiator. The hydrogel precursor composition is photocurable and thermally responsive. A thermally responsive hydrogel is formed by photopolymerizing the hydrogel precursor composition. The thermally responsive hydrogel may be used to mimic the activity of muscle fibers.

Abstract: Various embodiments for a foldable quad-rotor (FQR) inspired by an origami mechanism are disclosed herein. The FQR can fold its arms during flight to enable aggressive turning maneuvers and operations in cluttered environments. A dynamic model of folding is built for this system with the collected data, and a feedback controller is designed to control the position and orientation of the FQR. Lyapunov stability analysis is conducted to show that the system is stable during arm folding and extension, and motion planning of the FQR is achieved based on a modified minimum-snap trajectory generation method.

Abstract: In one aspect, a device for providing propulsion in water is provided by the present disclosure. The device includes a parallel mechanism including at least five rigid bars and at least five joints, each joint being positioned between two of the rigid bars and configured to allow movement of the at least five rigid bars, a first servo motor coupled to a first rigid bar included in the at least five rigid bars, a second servo motor coupled to a second rigid bar included in the at least five rigid bars, and a controller coupled to the first servo motor and the second servo motor and configured to actuate the first servo motor and the second servo motor according to a predetermined pattern.

Abstract: Various embodiments of a foldable unmanned aerial vehicle having a multi-layer laminate structure and extendible arms are disclosed.

Abstract: A multilayer electrolaminate structure includes a first electrolaminate layer and a second electrolaminate layer disposed adjacent the first electrolaminate layer. Each of the first and second electrolaminate layers is rotatable about a common axis independently of the other electrolaminate layer when the multilayer electrolaminate structure is in a first state and clamps to the other electrolaminate layer when the multilayer electrolaminate structure is in a second state.

Abstract: A twisted string actuator system includes a motor generating rotary motion of a rotor and a twisted string comprised of a pair of cords. One end of the twisted string is attached to the rotor and an opposite end of the twisted string is coupled to a load. The cords are twisted about each other for a first section of the twisted string and untwisted for a second section of the twisted string. A cord guide is fixedly disposed between the cords. The first and second sections of the twisted string are on a first side and second side, respectively, of the cord guide. Rotary motion of the rotor in one direction operates to twist the pair of cords on the first side of the cord guide while pulling a portion of the pair of cords from the second side of the cord guide into the first side.

Abstract: A twisted string actuator system includes a motor generating rotary motion of a rotor and a twisted string comprised of a pair of cords. One end of the twisted string is attached to the rotor and an opposite end of the twisted string is coupled to a load. The cords are twisted about each other for a first section of the twisted string and untwisted for a second section of the twisted string. A cord guide is fixedly disposed between the cords. The first and second sections of the twisted string are on a first side and second side, respectively, of the cord guide. Rotary motion of the rotor in one direction operates to twist the pair of cords on the first side of the cord guide while pulling a portion of the pair of cords from the second side of the cord guide into the first side.

Abstract: A multilayer electrolaminate structure includes a first electrolaminate layer and a second electrolaminate layer disposed adjacent the first electrolaminate layer. Each of the first and second electrolaminate layers is rotatable about a common axis independently of the other electrolaminate layer when the multilayer electrolaminate structure is in a first state and clamps to the other electrolaminate layer when the multilayer electrolaminate structure is in a second state.

Abstract: Robotic hands and finger modules include an underactuated finger with multiple joints including a distal joint, an intermediate joint, and a proximal joint. A brake subsystem in communication with each of the joints selectively locks and unlocks the joints individually. A robotic hand can selectively lock the joints of a finger individually such that one or more joints are locked while one or more joints are unlocked. In addition, the finger module can drive a tendon coupled to the joints to flex the underactuated finger in a manner determined by which of the joints is locked and which of the joints is unlocked. A robotic hand can move an underactuated finger with its distal and proximal joints unlocked until the finger makes contact with an object, and lock the proximal joint, in response to contact made with the object, while the distal joint remains unlocked.

Abstract: Robotic hands and finger modules include an under-actuated finger with multiple joints including a distal joint, an intermediate joint, and a proximal joint. A brake subsystem in communication with each of the joints selectively locks and unlocks the joints individually. A robotic hand can selectively lock the joints of a finger individually such that one or more joints are locked while one or more joints are unlocked. In addition, the finger module can drive a tendon coupled to the joints to flex the underactuated finger in a manner determined by which of the joints is locked and which of the joints is unlocked. A robotic hand can move an underactuated finger with its distal and proximal joints unlocked until the finger makes contact with an object, and lock the proximal joint, in response to contact made with the object, while the distal joint remains unlocked.