Energy harvester for converting motion to electricity using one or more multiple degree of freedom pendulums

An energy harvester system (EHS) for converting a multiple degree of freedom (MDF) pendulum motion into a rotational motion is provided. The EHS includes a pendulum, a pointing element, and motion control slots (MCSs) enclosed in an external housing. Ambient motion from the external housing generates a MDF pendulum motion in the pendulum. The pointing element is slidably positioned on a rod of the pendulum. The MCSs receive a connector that connects the pointing element to the rod of the pendulum and allow the connector to traverse the MCSs, thereby controlling slidable movement of the pointing element along with the pendulum. When the pendulum moves to first ends of the MCSs, the pointing element slides on the rod to allow a pointer of the pointing element to contact and rotate a gear, thereby converting the MDF pendulum motion into a rotational motion of the gear, which drives an electric generator.

BACKGROUND

In an era that emphasizes green technology, technologies relating to energy harvesting are becoming important. There is a need for finding new ways to save and reuse energy, while also making it affordable to do so. Energy harvesting refers to a process of capturing energy from external sources comprising, for example, sunlight, kinetic energy, wind, hydraulics, etc. Energy that is harvested from different sources is typically bountiful, and is present regardless of whether energy harvesting takes place. The harvested energy is typically converted to electricity to power electronic devices. Since energy harvesting does not depend on batteries or power sockets, the harvested energy is used as a power source in multiple different industries and portable electronic devices. For example, users can use the harvested energy to charge portable devices such as smartphones without the need to connect their smartphones to a power socket, thereby allowing the users to charge their smartphones on the go. Other electronic devices, for example, communication radios and flashlights can also use power from energy harvesting technologies in locations such as underground mines, deserts, and remote areas, where power sources are unavailable.

There are many conventional energy harvesting systems which generate electrical energy from mechanical motion, vibrations, etc. For example, a conventional energy harvesting system generates electrical energy from vibrations using piezoelectric materials. The piezoelectric materials create a charge when stressed. With these piezoelectric materials, each generator of 1 cubic centimeter in volume generates up to 0.5 milliwatts and can potentially be used to drive small autonomous devices such as pacemakers, wristwatches, or wireless sensors. Piezoelectric materials based energy harvester systems provide renewable electrical power from arbitrary, non-periodic vibrations. The non-periodic vibrations are obtained, for example, from traffic driving on bridges, machinery operating in industries, and humans moving their limbs. The conventional energy harvesting systems using piezoelectric materials generate insufficient power to power a standard portable electronic device. Further, the piezoelectric materials are expensive. Therefore, there is a need for an improved energy harvesting system that generates optimum electrical energy.

Hence, there is a long felt but unresolved need for an energy harvester system that converts a multiple degree of freedom pendulum motion into a rotational motion for generation of electrical energy to power portable electronic devices.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in a simplified form that are further disclosed in the detailed description of the invention. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.

The energy harvester system disclosed herein addresses the above mentioned need for converting a multiple degree of freedom pendulum motion into a rotational motion for generation of electrical energy to power portable electronic devices. The energy harvester system disclosed herein comprises an external housing, a pendulum housing, a pendulum, a pointing element, and motion control slots. The external housing is defined by multiple walls. The pendulum housing is fixedly attached to one of the walls of the external housing. The pendulum housing comprises opposing walls substantially parallel to each other. The pendulum is positioned between the opposing walls of the pendulum housing. The pendulum is pivotally connected to upper ends of the opposing walls of the pendulum housing via a pivot pin. The pendulum comprises a rod and a mass. The mass of the pendulum is rigidly connected to a distal end of the rod of the pendulum. An ambient motion from one or more of the walls of the external housing generates a multiple degree of freedom pendulum motion in the pendulum, causing the pendulum to move in a first direction and a second direction opposing the first direction. The pointing element is slidably positioned on the rod of the pendulum and is connected to the rod of the pendulum by a connector. The pointing element comprises an elongate member and a pointer. The pointer is positioned on an upper end of the elongate member. The pointing element moves along with the rod of the pendulum. A motion control slot is configured on each of the opposing walls of the pendulum housing to receive the connector that connects the pointing element to the rod of the pendulum and allow the connector to traverse the motion control slots on the opposing walls of the pendulum housing in the first direction and the second direction, thereby controlling slidable movement of the pointing element along with the pendulum. The pointing element slides on the rod of the pendulum in an upward direction to allow the pointer of the pointing element to engageably contact a gear positioned above the pointer within the external housing to rotate the gear, when the pendulum moves to first ends of the motion control slots in the first direction via the connector, thereby converting the multiple degree of freedom pendulum motion of the pendulum into a rotational motion of the gear. The rotational motion of the gear drives an electric generator operably connected to the gear for generation of electrical energy.

In an embodiment, the energy harvester system disclosed herein comprises an external housing and at least two pendulum assemblies. In this embodiment, each of the pendulum assemblies is fixedly attached to the opposing walls of the external housing and is positioned substantially perpendicular to a gear within the external housing. In another embodiment, each of the pendulum assemblies is fixedly attached to the opposing walls of the external housing and is positioned substantially parallel to each other and the gear within the external housing. In these embodiments, each of the pendulum assemblies comprises a pendulum housing, a pendulum, a pointing element, and motion control slots as disclosed above. In these embodiments, an orientation of the motion control slots on the opposing walls of the pendulum housing of one of the pendulum assemblies opposes an orientation of the motion control slots on the opposing walls of the pendulum housing of the other pendulum assembly. The connector of one of the pendulum assemblies traverses to the first ends of the motion control slots in the first direction, while the connector of the other pendulum assembly traverses to the second ends of the motion control slots in the first direction. In these embodiments, the pointing element on the pendulum of each of the pendulum assemblies alternately slides on the rod of the pendulum of a corresponding pendulum assembly in an upward direction to allow the pointer of the pointing element to engageably contact the gear positioned above the pointer alternately to rotate the gear, when the pendulum of each of the pendulum assemblies alternately moves to the first ends of the motion control slots in the first direction via the connector, thereby converting the multiple degree of freedom pendulum motion of the pendulum into the rotational motion of the gear. The rotational motion of the gear drives an electric generator operably connected to the gear for generation of electrical energy.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1exemplarily illustrates a perspective view of an energy harvester system100for converting a multiple degree of freedom pendulum motion into a rotational motion for generation of electrical energy. The energy harvester system100disclosed herein comprises an external housing101, a pendulum housing102, a pendulum105, a pivot pin108, a pointing element109, motion control slots113and114, and a connector112. The external housing101of the energy harvester system100is defined by multiple walls101a,101b,101c,101d,101e, and101f, for example, a top wall101b, a bottom wall101a, a front wall101f, a rear wall101e, and side walls101cand101d. The external housing101encloses the pendulum housing102. In an embodiment, the external housing101is a box of a geometric shape, for example, a cuboidal shape as exemplarily illustrated inFIG. 1. The pendulum housing102of the energy harvester system100is fixedly attached to one of the walls, for example, the bottom wall101aof the external housing101as exemplarily illustrated inFIG. 1. The pendulum housing102comprises opposing walls103and104substantially parallel to each other.

The pendulum105of the energy harvester system100is positioned between the opposing walls103and104of the pendulum housing102. The pendulum105is pivotally connected to the upper ends103aand104aof the opposing walls103and104of the pendulum housing102respectively, via the pivot pin108. The pendulum105comprises a rod106and a mass107. The mass107of the pendulum105is rigidly connected to a distal end106aof the rod106of the pendulum105. An ambient motion from one or more of the walls101a,101b,101c,101d,101e, and101f, for example, from the bottom wall101aof the external housing101, generates a multiple degree of freedom pendulum motion in the pendulum105, causing the pendulum105to move in a first direction and a second direction. For example, the pendulum motion in the pendulum105causes the pendulum105to move in a right direction and a left direction. As used herein, “ambient motion” refers to motion of the external housing101due to a movement of a surface to which the external housing101is attached. For example, the external housing101can be attached to a wall of a vehicle. In this example, when the vehicle moves, the external housing101moves, which in turn, moves the pendulum105in the first direction, for example, the right direction, and the second direction, for example, the left direction.

The pointing element109of the energy harvester system100is slidably positioned on the rod106of the pendulum105and connected to the rod106of the pendulum105by the connector112. The pointing element109comprises an elongate member110and a pointer111. The pointer111of the pointing element109is positioned on an upper end110aof the elongate member110of the pointing element109. In an embodiment as exemplarily illustrated inFIG. 1, the pointer111comprises teeth111aconfigured to engage with gear teeth115aof a gear115. The pointing element109moves along with the rod106of the pendulum105. In an embodiment, the pointing element109is positioned substantially perpendicular to the gear115.

The motion control slots113and114of the energy harvester system100are configured on the opposing walls103and104of the pendulum housing102respectively, to receive the connector112that connects the pointing element109to the rod106of the pendulum105and allow the connector112to traverse the motion control slots113and114in the first direction and the second direction, thereby controlling slidable movement of the pointing element109along with the pendulum105. The motion control slots113and114direct the pointing element109positioned on the rod106of the pendulum105to follow a predetermined path. The motion control slots113and114comprise first ends113aand114aand second ends113band114brespectively, as exemplarily illustrated inFIG. 2. The second ends113band114bof the motion control slots113and114respectively, are configured to be positioned at a lower position than the first ends113aand114aof the motion control slots113and114respectively.

When the pendulum105moves to the first ends113aand114aof the motion control slots113and114respectively, in the first direction via the connector112, the pointing element109slides on the rod106of the pendulum105in an upward direction to allow the pointer111of the pointing element109to engageably contact the gear115positioned above the pointer111within the external housing101to rotate the gear115, thereby converting the multiple degree of freedom pendulum motion of the pendulum105into a rotational motion of the gear115. That is, when the pendulum105moves to the first ends113aand114aof the motion control slots113and114respectively, which are at a higher position than the second ends113band114bof the motion control slots113and114respectively, for example, in a right direction via the connector112, the motion control slots113and114slide the pointing element109in an upward direction to an extreme high position to allow the pointer111of the pointing element109to contact and turn the gear115connected to an electric generator (not shown), for example, an alternating current (AC) generator. The gear115is operably connected to the electrical generator. The rotational motion of the gear115drives the electric generator for generation of electrical energy.

When the pendulum105moves to the second ends113band114bof the motion control slots113and114respectively, in the second direction, for example, the left direction, via the connector112, the motion control slots113and114force the pointing element109to slide in a downward direction to an extreme low position to disengage the pointer111of the pointing element109from the gear115to preclude an opposing rotation of the gear115. The left-right movement of the pendulum105is therefore translated into a unidirectional motion, that is, the rotational motion of the gear115. The energy harvester system100therefore converts mechanical motion, for example, the multiple degree of freedom pendulum motion induced by movement of a vehicle to a rotational motion of the gear115, which drives the electric generator.

Energy required to drive the electric generator for generation of electrical energy depends on a ratio of a distance between the pivot pin108and the mass107of the pendulum105to a distance between the pivot pin108and the gear teeth115aof the gear115. In the energy harvester system100exemplarily illustrated inFIG. 1, this ratio is, for example, about 50. If the ratio of the distance between the pivot pin108and the mass107of the pendulum105to the distance between the pivot pin108and the gear teeth115ais 50, the force exerted by the mass107of the pendulum105is amplified 50 times when delivered to the gear115, thereby driving the electric generator, which typically requires a large amount of energy. Since a large force is delivered to the gear teeth115a, one left-right movement of the pendulum105pushes the gear115multiple teeth115aforward, which drives the electric generator. The energy harvester system100therefore harvests energy from mechanical motion, and optimally converts the harvested energy to drive the gear115of the electric generator.

In an embodiment, the energy harvester system100and the electric generator is packaged in the external housing101, for example, an electric box of size 2×6×10 cm3weighing less than about 300 grams to produce more than about 100 milliwatts (mW) of power with a potential to output, for example, 5V and 100 mA, totaling to 500 mW of power. This power is, for example, used to charge batteries of portable electronic devices.

FIG. 2exemplarily illustrates an exploded view of the energy harvester system100. As exemplarily illustrated inFIG. 2, the energy harvester system100disclosed herein comprises the pendulum housing102with two opposing walls103and104, the pendulum105with the rod106and the mass107, the pointing element109with the elongate member110and the pointer111that engages to the gear115, the pivot pin108, and the connector112as disclosed in the detailed description ofFIG. 1. One opposing wall103of the pendulum housing102exemplarily illustrated inFIG. 1, comprises an opening103dat the upper end103aof the wall103and openings103eand103fat the two corners103band103cof the wall103respectively, while the other opposing wall104of the pendulum housing102comprises an opening104dat the upper end104aof the wall104and openings104eand104fat the two corners104band104cof the wall104respectively. Fasteners120aand120bare inserted into the openings103e,104eand103f,104frespectively, of the opposing walls103and104to fasten the opposing walls103and104of the pendulum housing102together, for example, using nuts121band121d. The fasteners120aand120bare, for example, bolts for fastening the opposing walls103and104of the pendulum housing102using the nuts121band121drespectively. The fasteners120aand120bpass through the openings103e,104eand103f,104frespectively, of the opposing walls103and104, and then through the openings101hand101iof the bottom wall101aof the external housing101exemplarily illustrated inFIG. 1, to be fastened, for example, using the nuts121band121d.

As exemplarily illustrated inFIG. 2, the pendulum105further comprises a slot117and an opening118positioned on the rod106of the pendulum105. The slot117is configured to receive the connector112that connects the pointing element109to the rod106of the pendulum105to allow the connector112to traverse the motion control slots113and114of the opposing walls103and104of the pendulum housing102respectively, and move the pointing element109along with the rod106of the pendulum105. The pointer111of the pointing element109is positioned on the upper end110aof the elongate member110of the pointing element109. The pointing element109further comprises a slot116and an opening119positioned on the elongate member110of the pointing element109. The slot116is configured to receive the pivot pin108that pivots the pendulum105to the pendulum housing102to allow the pointing element109to slide on the rod106of the pendulum105. The pivot pin108is configured to pass through the opening103dat the upper end103aof one wall103of the pendulum housing102, the slot116of the pointing element109, the opening118of the pendulum105, and the opening104dat the upper end104aof the other wall104of the pendulum housing102. The inserted pivot pin108is then fastened through an opening101gin the bottom wall101aof the external housing101, for example, using a nut121c. The connector112is configured to pass through the motion control slot113of one wall103of the pendulum housing102, the opening119of the pointing element109, the slot117of the pendulum105, and the motion control slot114of the other wall104of the pendulum housing102. The inserted connector112is then fastened to the other wall104of the pendulum housing102, for example, using a nut121a.

FIGS. 3A-3Cexemplarily illustrate perspective views of the energy harvester system100, showing a cutaway pendulum housing102shown inFIG. 1, with one wall, for example,104to illustrate an operation of the energy harvester system100for converting a multiple degree of freedom pendulum motion into a rotational motion. The pendulum105is at an equilibrium position when there is no pendulum motion as exemplarily illustrated inFIG. 3A. An ambient motion, for example, from the bottom wall101aof the external housing101generates a multiple degree of freedom pendulum motion in the pendulum105, which moves the pendulum105in a first direction, for example, a right direction towards the first ends113aand114aof the motion control slots113and114respectively, and in a second direction, for example, a left direction towards the second ends113band114bof the motion control slots113and114respectively. The pointing element109moves along with the rod106of the pendulum105in the first direction and the second direction. As exemplarily illustrated inFIG. 3B, when the pendulum105moves towards the first ends113aand114aof the motion control slots113and114respectively, in the first direction, for example, the right direction via the connector112exemplarily illustrated inFIGS. 1-2, the pointing element109slidably positioned on the rod106of the pendulum105slides on the rod106of the pendulum105via the slot116in an upward direction towards the gear115to allow the pointer111of the pointing element109to contact the gear115.

When the pendulum105reaches the extreme high position at the first ends113aand114aof the motion control slots113and114respectively, the teeth111aof the pointer111of the pointing element109engageably contacts the gear teeth115aand moves in a second direction, for example, the left direction to rotate the gear115as exemplarily illustrated in theFIG. 3C, thereby converting the multiple degree of freedom pendulum motion of the pendulum105into a rotational motion of the gear115. The rotational motion of the gear115is used to drive an electric generator (not shown) that generates electrical energy or electricity. When the pendulum105moves towards the second ends113band114bof the motion control slots113and114respectively, in the second direction, for example, the left direction via the connector112as exemplarily illustrated inFIG. 3D, the pointing element109slidably positioned on the rod106of the pendulum105slides on the rod106of the pendulum105via the slot116in a downward direction, disengages the teeth111aof the pointer111from the gear teeth115ato preclude an opposing rotation of the gear115, and moves in a first direction, for example, the right direction.

FIG. 4exemplarily illustrates an elevation view of an embodiment of the energy harvester system100, showing a pendulum assembly401with a bow shaped motion control slot113, positioned perpendicular to a gear115. In an embodiment, the pendulum assembly401comprising the pendulum housing102, the pendulum105, the pointing element109, the pivot pin108, the motion control slots113and114, and the connector112is positioned substantially perpendicular to the gear115as exemplarily illustrated inFIG. 4. Furthermore, in an embodiment, the motion control slots113and114of a bow shape are carved on the opposing walls103and104of the pendulum housing102respectively, as exemplarily illustrated inFIG. 2. When a multiple degree of freedom pendulum motion is generated in the pendulum105, the connector112traverses the bow shaped motion control slots113and114towards the first ends113aand114aof the bow shaped motion control slots113and114respectively, in a first direction, for example, the right direction, and towards the second ends113band114bof the bow shaped motion control slots113and114respectively, in a second direction, for example, the left direction.

When the pendulum105moves towards the first ends113aand114aof the bow shaped motion control slots113and114respectively, in the first direction, for example, the right direction via the connector112, the pointing element109positioned on the rod106of the pendulum105slides on the rod106of the pendulum105via the slot116in an upward direction and moves towards the gear115positioned perpendicularly above the pointing element109. When the pendulum105reaches the extreme high position at the first ends113aand114aof the bow shaped motion control slots113and114respectively, the teeth111aof the pointer111of the pointing element109engageably contacts the gear teeth115aand moves the pointing element109in a second direction, for example, the left direction, thereby rotating the gear115and converting the multiple degree of freedom pendulum motion of the pendulum105into a rotational motion of the gear115.

FIG. 5exemplarily illustrates an elevation view of an embodiment of the energy harvester system100, showing a pendulum assembly401with a zigzag shaped motion control slot113, positioned perpendicular to a gear115. As exemplarily illustrated inFIG. 5, in an embodiment, the pendulum assembly401comprising the pendulum housing102, the pendulum105, the pointing element109, the pivot pin108, the motion control slots113and114, and the connector112is positioned substantially perpendicular to the gear115. Furthermore, in an embodiment, the motion control slots113and114of a zigzag shape are carved in the opposing walls103and104of the pendulum housing102respectively, as exemplarily illustrated inFIG. 2. When a multiple degree of freedom pendulum motion is generated in the pendulum105, the connector112traverses the zigzag shaped motion control slots113and114in a zigzag manner, that is, the connector112traverses through the sharp turns of the zigzag shaped motion control slots113and114in an upward-downward manner, towards the first ends113aand114aof the zigzag shaped motion control slots113and114respectively, in a first direction, for example, the right direction, and towards the second ends113band114bof the zigzag shaped motion control slots113and114respectively, in a second direction, for example, the left direction. The pendulum105follows an up and down motion directed by the zigzag shaped motion control slots113and114. The zigzag shaped motion control slots113and114allow the pointer111of the pointing element109to turn multiple gear teeth115aof the gear115.

When the pendulum105moves towards the first ends113aand114aof the zigzag shaped motion control slots113and114respectively, in the first direction, for example, the right direction via the connector112, the pointing element109positioned on the rod106of the pendulum105slides on the rod106of the pendulum105via the slot116in an upward direction and moves towards the gear115positioned perpendicularly above the pointing element109. When the pendulum105reaches the extreme high position at the first ends113aand114aof the zigzag shaped motion control slots113and114respectively, the teeth111aof the pointer111positioned on the upper end110aof the elongate member110of the pointing element109engageably contacts the gear teeth115aand moves the pointing element109in a second direction, for example, the left direction, thereby rotating the gear115and converting the multiple degree of freedom pendulum motion of the pendulum105into a rotational motion of the gear115.

FIG. 6exemplarily illustrates a method for converting a multiple degree of freedom pendulum motion into a rotational motion for generation of electrical energy using the energy harvester system100shown inFIGS. 1-5. In the method disclosed herein, the energy harvester system100comprising the external housing101, the pendulum housing102, the pendulum105, the pointing element109, and the motion control slots113and114as exemplarily illustrated inFIGS. 1-5and as disclosed in the detailed description ofFIGS. 1-5, is provided601. An ambient motion from one or more of the walls101a,101b,101c,101d,101e, and101fof the external housing101generates602a multiple degree of freedom pendulum motion in the pendulum105of the energy harvester system100, causing the pendulum105to move in a first direction, for example, a right direction, and a second direction, for example, a left direction opposing the first direction. When the pendulum105moves to the first ends113aand114aof the motion control slots113and114respectively, in the first direction via the connector112, the pointing element109slides603on the rod106of the pendulum105via the slot116in an upward direction towards a gear115positioned above the pointer111of the pointing element109within the external housing101to allow the pointer111of the pointing element109to engageably contact the gear115. The engageable contact of the pointer111of the pointing element109with the gear115rotates604the gear115, thereby converting the multiple degree of freedom pendulum motion of the pendulum105into a rotational motion of the gear115, which drives an electric generator (not shown) operably connected to the gear115to generate electrical energy.

FIG. 7exemplarily illustrates a perspective view of an embodiment of the energy harvester system100comprising two pendulum assemblies701and702positioned substantially perpendicular to a gear115. In this embodiment, the energy harvester system100comprises an external housing101(not shown inFIG. 7) and at least two pendulum assemblies701and702fixedly attached to opposing walls, for example,101aand101bof the external housing101. In this embodiment, the two pendulum assemblies701and702are positioned substantially perpendicular to the gear115within the external housing101. In this embodiment, each of the pendulum assemblies701and702comprises a pendulum housing102, a pendulum105, a pointing element109, and motion control slots113and114as disclosed in the detailed description ofFIGS. 1-2. Furthermore, in this embodiment, the motion control slots113and114on the pendulum housings102of the two pendulum assemblies701and702have opposing orientations as exemplarily illustrated inFIG. 7.

The pointing element109on the pendulum105of each of the two pendulum assemblies701and702is configured to alternately slide on the rod106of the pendulum105of a corresponding one of the two pendulum assemblies701and702via the slot116in an upward direction to allow the pointer111of the pointing element109to engageably contact the gear115positioned above the pointer111alternately to rotate the gear115, when the pendulum105of each of the two pendulum assemblies701and702alternately moves to the first ends113aand114aof the motion control slots113and114respectively via the connector112, thereby converting the multiple degree of freedom pendulum motion of the pendulum105into the rotational motion of the gear115, which drives an electric generator (not shown) for generation of electrical energy.

FIG. 8exemplarily illustrates a perspective view of an embodiment of the energy harvester system100comprising two pendulum assemblies701and702positioned substantially parallel to each other and a gear115. In this embodiment, the energy harvester system100comprises an external housing101(not shown inFIG. 8) and at least two pendulum assemblies701and702fixedly attached to opposing walls, for example,101aand101bof the external housing101. In this embodiment, the two pendulum assemblies701and702are positioned substantially parallel to each other and to the gear115within the external housing101. In this embodiment, the two pendulum assemblies701and702are positioned parallel to rotate a gear115of a large thickness alternately. Each of the pendulum assemblies701and702comprises a pendulum housing102, a pendulum105, a pointing element109, and motion control slots113and114as disclosed in the detailed description ofFIGS. 1-2. In this embodiment, the motion control slots113and114on the pendulum housings102of the two pendulum assemblies701and702respectively, have an opposing orientation, with the second ends113band114bof the motion control slots113and114respectively, positioned at a lower position than the first ends113aand114aof the motion control slots113and114respectively.

The pointing elements109on the pendulums105of the two pendulum assemblies701and702are configured to alternately slide on the rods106of the pendulums105of the corresponding pendulum assemblies701and702respectively, via the slot116in an upward direction to allow the pointers111of the pointing elements109of the two pendulum assemblies701and702to engageably contact the gear115positioned above the pointers111alternately to rotate the gear115, when the pendulums105of the two pendulum assemblies701and702alternately move to the first ends113aand114aof the motion control slots113and114respectively via the connector112, thereby converting the multiple degree of freedom pendulum motion of the pendulum105into a rotational motion of the gear115, which drives an electric generator (not shown) operably connected to the gear115to generate electrical energy.

In the embodiment exemplarily illustrated inFIG. 8, the pointing elements109attached to the rods106of the pendulums105of the pendulum assemblies701and702swing continuously as the pendulums105swing. The two pointing elements109swing to the right alternately while turning the gear115due to the opposing orientations of the motion control slots113and114in the pendulum assemblies701and702, and then swing to the left alternately as the pendulums105swing back. Adding the second pendulum assembly702with the pointing element109makes the energy harvester system100generate more electrical energy or electricity, because the second pointing element109doubles the number of the gear teeth115aof the gear115turned.

FIG. 9exemplarily illustrates an embodiment of the method for converting a multiple degree of freedom pendulum motion into a rotational motion for generation of electrical energy using the embodiments of the energy harvester system100shown inFIGS. 7-8. In this embodiment of the method disclosed herein, the energy harvester system100comprising an external housing101(not shown inFIGS. 7-8) and at least two pendulum assemblies701and702fixedly attached to the opposing walls101aand101bof the external housing101is provided901. In the embodiment exemplarily illustrated inFIG. 7, the two pendulum assemblies701and702are positioned substantially perpendicular to a gear115within the external housing101. In the embodiment exemplarily illustrated inFIG. 8, the two pendulum assemblies701and702are positioned substantially parallel to each other and the gear115. The method for converting a multiple degree of freedom pendulum motion into a rotational motion for generation of electrical energy using both the embodiments exemplarily illustrated inFIGS. 7-8is as follows: An ambient motion from one or more of the walls101a,101b,101c,101d,101e, and101fof the external housing101of the energy harvester system100generates902a multiple degree of freedom pendulum motion in the pendulum105of each of the two pendulum assemblies701and702, causing the pendulum105of each of the two pendulum assemblies701and702to move in a first direction, for example, a right direction, and a second direction, for example, a left direction opposing the first direction. When the pendulums105of the two pendulum assemblies701and702exemplarily illustrated inFIG. 7-8, alternately move to the first ends113aand114aof their respective motion control slots113and114in the first direction via their respective connectors112, the pointing elements109of the two pendulum assemblies701and702alternately slide903on the rods106of the pendulums105of the corresponding two pendulum assemblies701and702in an upward direction towards the gear115positioned above the pointers111of the pointing elements109within the external housing101to allow the pointers111of the pointing elements109of the pendulum assemblies701and702to engageably contact the gear115alternately.

In an example, in the embodiments exemplarily illustrated inFIGS. 7-8, due to the opposing orientations of the motion control slots113and114of the two pendulum assemblies701and702, when the pendulums105of the two pendulum assemblies701and702move together in the first direction, for example, the right direction, the connector112of one of the two pendulum assemblies701and702traverses to the first ends113aand114aof the motion control slots113and114respectively, on the opposing walls103and104of the corresponding pendulum housing102in the first direction, while the connector112of the other one of the two pendulum assemblies701and702traverses to the second ends113band114bof the motion control slots113and114respectively, on the opposing walls103and104of the corresponding pendulum housing102in the first direction. The pointing element109of one pendulum assembly701therefore slides on the rod106of the pendulum105of the corresponding pendulum assembly701in an upward direction towards the gear115positioned above the pointer111of the pointing element109within the external housing101to allow the pointer111of the pointing element109of that pendulum assembly701to engageably contact the gear115, while the pointing element109of the other pendulum assembly702slides on the rod106of the pendulum105of the corresponding pendulum assembly702in a downward direction away from the gear115to allow the pointer111of the pointing element109of the other pendulum assembly702to disengage from the gear115to preclude an opposing rotation of the gear115. The alternate engageable contact of the pointers111of the pointing elements109of the pendulum assemblies701and702with the gear115rotates904the gear115, thereby converting the multiple degree of freedom pendulum motion of the pendulum105into a rotation motion of the gear115. The rotational motion of the gear115drives an electric generator (not shown) operably connected to the gear115for generation of electrical energy.

FIGS. 10A-10Cexemplarily illustrate an experimental setup of the energy harvester system100. The energy harvester system100disclosed herein converts a multiple degree of freedom pendulum motion to a rotational motion of a gear115operably connected to an electric generator, for example, an alternating current (AC) generator1001to drive the AC generator1001. In an experiment, a mini three-phase AC generator1001is operably connected to the gear115of the energy harvester system100exemplarily illustrated inFIG. 1, to generate an output power of, for example, about 3V to 5V and about 100 mA to about 250 mA. The energy harvester system100together with the mini three phase AC generator1001as exemplarily illustrated inFIG. 10A, is packaged in a box that is attached to a wall of a vehicle to harvest energy from mechanical motion. The output power depends on speed of the energy harvester system100during motion of the vehicle. For a low frequency movement of, for example, about 5 Hz, the AC generator1001generates a three phase AC output power of, for example, about 50 mW to about 100 mW. The three phase AC output is used to provide an AC load to power devices, for example, a lamp, an electric shaver, etc. A three phase rectifier comprising six diodes can be used to convert the three phase AC output to a direct current (DC). The DC output can then be connected to a Lithium ion (Li+) battery charger.

In another example, the mini three phase alternating current (AC) generator1001is used to power a light emitting diode (LED)1002of 1.5V and 25 mA via a connecting electric wire1003as exemplarily illustrated inFIG. 10A. The AC generator1001generates an output power of, for example, about 40 mW. In another example, the energy harvester system100is used to drive ten parallel LEDs1002with a 3V diode drop and 5 mA, each via a connecting electrical wire1003as exemplarily illustrated inFIGS. 10B-10C, to generate a total output power of, for example, about 150 mW.

FIG. 11exemplarily illustrates a graphical representation showing an output of the energy harvester system100exemplarily illustrated inFIG. 1. The alternating current (AC) generator1001driven by the energy harvester system100exemplarily illustrated inFIGS. 10A-10C, which is directly connected to an oscilloscope, outputs a peak voltage of, for example, about +/−10V. The ripples in the graphical representation indicate that one push of the pointer111of the pointing element109of the energy harvester system100on the gear115exemplarily illustrated inFIG. 1, can turn the AC generator1001multiple times.