A portion of ankle movement can be harnessed into stored energy that can be released for various purposes, such as to assist in movement or to charge a battery. This harnessing can be achieved in various manners. In one example manner, an offset pulley component can transfer ankle movement to a generator in a shoe insole. In another example manner, a slider can cause a brace arch to match an ankle arch such that the movement is appropriately harnessed.

A wearable system, such as a footwear system, can employ a generator. The generator can be powered by human movement, such as movement of knee as a person walks or runs. When the knee resets, it can be desirable to have a relatively equal gear ratio to achieve near natural movement. Conversely, it can be desirable to have a high gear ratio when the knee pushes off to achieve high generator rotation to produce a high amount of power. This can be achieved with employment of a wearable planetary gear set configuration In practicing this wearable planetary gear set, torque can be provided from the source (e.g. human ankle joint) when power negative and not at other times during a movement cycle, meaning energy can be harvested from the walking motion without inducing additional burden to the device wearer.

A footwear system can employ a brake and/or a clutch, such as a one-way clutch, to convert human motion into usable electricity. The brake and one-way clutch can be used together, such as on opposite ends of a spring. During a storage phase, the brake can be engaged and the one-way clutch disengaged so the spring stores an energy. After the storage phase, the brake can be removed to initiate the release phase since the brake is not stopping the spring, but the one-way clutch allows the stored energy to be released.

A wearable system, such as a footwear system, can employ a generator. The generator can be an electro-mechanical generator with a portion that spins to create an electricity. The portion that spins can be spun in such a manner that it does not stop, but instead a next spin beings before a previous spin completes. This can repeat until the generator reaches a terminal velocity.

A device that attaches to three body segments connected by two joints harvests energy selectively from one of the two joints using a single motor-generator. The device also selectively augments relative body segment motion about one of the two joints. Selection of the harvesting or generating mode depends on the user's preference. When in a particular mode, the device automatically selects which of the two joints to connect to the motor-generator in order to optimize the augmentation or harvesting. Depending on whether the user is on flat terrain, going up an incline or down a decline, the selection of the joint to be connected is different. Use of a single motor-generator and gearbox mounted near the knee reduces metabolic cost compared to the use of two motor-generators and gearboxes.

A device that attaches to three body segments connected by two joints harvests energy selectively from one of the two joints using a single motor-generator. The device also selectively augments relative body segment motion about one of the two joints. Selection of the harvesting or generating mode depends on the user's preference. When in a particular mode, the device automatically selects which of the two joints to connect to the motor-generator in order to optimize the augmentation or harvesting. Depending on whether the user is on flat terrain, going up an incline or down a decline, the selection of the joint to be connected is different. Use of a single motor-generator and gearbox mounted near the knee reduces metabolic cost compared to the use of two motor-generators and gearboxes.

A method of mechanical-to-electrical energy conversion utilizes a mechanical spring in combination with a rapid-action variable inductance magnetic flux switch to convert a spring-loaded mechanical energy into a change in magnetic flux captured by an electrical coil element within the magnetic flux switch. The change in coil inductance and magnetic flux induces a current to flow through the electrical coil in the form of a a pulse of electrical energy that may be stored. The electrical coil is coupled to the mechanical spring so that each time the spring is released, the coil moves with respect to a magnetic core and a change in flux is created. The application of an external mechanical force (such as human locomotion) functions to compress and subsequently unlock the mechanical switch, allowing for the electrical energy associated with the application of aperiodic forces to be harvested.

A system that may be used for energy harvesting includes a flexible beam secured between a first support and a second support. The supports are spaced apart at a distance less than a length of the flexible beam such that the beam is buckled. Responsive to external vibrations the flexible beam switches between a first position and a second position. A magnetic proof mass is coupled to the flexible beam at the beam's midpoint. At least one permanent magnet is positioned proximate to the magnetic proof mass and has the same polarity. The permanent magnet is positioned to expose the magnetic proof mass to a repulsive force when the magnetic proof mass is located at both the first position and the second position. Piezoelectric transducers are located above and below the first and second positions of the flexible beam to harvest energy.

An energy harvesting system can comprise an actuator comprising a translationally displaceable surface, the translationally displaceable surface being configured to transition from a first position to a second position upon contact by a movable unit; a vertical rack in contact with the actuator, and configured to be translationally displaced in response to translational displacement of the actuator; a pinion configured to engage with the vertical rack and to rotate in response to translational displacement of the vertical rack; a main shaft coupled to the pinion and configured to rotate with rotation of the pinion; and a flywheel and a generator coupled to the main shaft, wherein rotation of the main shaft generates mechanical energy stored by the flywheel, and wherein the generator is configured to generate electrical energy from the mechanical energy stored by the flywheel.

A method of mechanical-to-electrical energy conversion utilizes a mechanical spring in combination with a rapid-action variable inductance magnetic flux switch to convert a spring-loaded mechanical energy into a change in magnetic flux captured by an electrical coil element within the magnetic flux switch. The change in coil inductance and magnetic flux induces a current to flow through the electrical coil in the form of a a pulse of electrical energy that may be stored. The electrical coil is coupled to the mechanical spring so that each time the spring is released, the coil moves with respect to a magnetic core and a change in flux is created. The application of an external mechanical force (such as human locomotion) functions to compress and subsequently unlock the mechanical switch, allowing for the electrical energy associated with the application of aperiodic forces to be harvested.