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: There is described a power converter for transforming electrical power between direct current (DC) power and alternating current (AC) power. The power converter has a first stage comprising a first branch having a first pair of series-connected switches, a second branch having a second pair of series-connected switches, and a capacitor connected between the first and second branches: a second stage comprising a third branch having a first plurality of series-connected switches, a fourth branch having a second plurality of series-connected switches, and a plurality of capacitors connected between the third and fourth branches at respective connection points located between intermediate switches of the first and second pluralities of series-connected switches; and a connection branch coupling the first stage and the second stage.

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 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: A multilevel power converter and method for transforming DC power from a DC source into AC power for an AC load are provided. The converter is composed of a half-bridge inverter, a switching cell, and a controller configured for controlling operation of the half-bridge inverter and the switching cell. The half-bridge inverter and the switching cell are connectable to the DC source and the AC load. The switching cell is composed of first and second pairs of switches forming first and second branches in parallel, first and second capacitors connected in series in a capacitor branch connected between the first and second branches, and a pair of back-to-back connected switches in a third branch, the third branch connected to the capacitor branch and connectable to the AC load.

Abstract: A multilevel power converter and method for transforming DC power from a DC source into AC power for an AC load are provided. The converter is composed of a half-bridge inverter, a switching cell, and a controller configured for controlling operation of the half-bridge inverter and the switching cell. The half-bridge inverter and the switching cell are connectable to the DC source and the AC load. The switching cell is composed of first and second pairs of switches forming first and second branches in parallel, first and second capacitors connected in series in a capacitor branch connected between the first and second branches, and a pair of back-to-back connected switches in a third branch, the third branch connected to the capacitor branch and connectable to the AC load.

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: 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.