WO2023242530A1

WO2023242530A1 - Energy harvesting device

Info

Publication number: WO2023242530A1
Application number: PCT/GB2023/050711
Authority: WO
Inventors: Allan Todd; Reg HARSLEY; Istavan CSAJAGHY; Marco MIGLIONICO; Ben CRICHTON
Original assignee: I4 Product Design Ltd
Current assignee: I4 Product Design Ltd
Priority date: 2022-06-15
Filing date: 2023-03-21
Publication date: 2023-12-21
Anticipated expiration: 2024-12-15
Also published as: GB202208776D0; GB2619740B; GB2619740A

Abstract

An energy harvesting device (100) has an energy conversion device (102) of the type which generates electrical energy in an outbound action and in a return action, and with a single button press from a user harvests energy from both the outbound and return actions.

Description

Energy Harvesting Device

TECHNICAL FIELD

The present disclosure relates to an energy harvesting device and a method of harvesting energy and in particular but not exclusively to a remote control device and method of remote control using energy harvesting devices and methods.

BACKGROUND

Energy harvesting relates to the concept of capturing and storing energy for use by a system from sources which are external to the system, such as from solar power, thermal energy, wind energy, salinity gradients and kinetic energy. Typically, this external power is converted to electrical energy which can be stored or used by the host system. Energy harvesting techniques are popular for small wireless autonomous devices of various types, and usually provide a small amount of power for low energy electronics.

The energy harvesting devices that employ kinetic energy usually rely upon an induced electromotive force being generated by relative motion of a magnetic member and a conductive member, most often in the form of a magnet encircled by a wire coil and which translates along an axis of the coil, thus generating an induced electromagnetic force in the coil to provide a useful voltage.

Other types of kinetic energy harvesting mechanisms include those which induce motion of ferrofluids or which rely on piezoelectric elements in which a crystal or fibre generates a voltage when deformed.

The motion that triggers the relative motion of the magnetic and conductive elements can arise from vibrations or general activity such as movement of a limb to power kinetic energy storage for a wrist watch or vibrations which can be used to harvest energy from a device which is in motion or being vibrated during use. Mechanical action can also be triggered by user-operable selection elements such as push buttons, keypads or touch screens. For example, it is known to provide keyboard buttons with magnetic shafts that translate or rotate within a conductive coil to generate power upon keys being depressed during typing, or to generate energy from pressing light switches or other types of buttons or switches.

This type of actuator generates electrical energy in two actions corresponding to opposite motions of the magnet relative to the conductive element; a first outbound action and a second return action. It is also possible for electrical energy to be generated in an outbound and a return action using different mechanisms, for example using a piezoelectric generator.

This relative motion may be a linear motion, in which case the direction is a translation along an axis, or it may be a rotational motion in which the two actions may be clockwise and anticlockwise rotations.

The outbound and return actions may respectively comprise a pressing action where an actuator urges a magnetic member to move in one direction when pressed, and a release action in which the magnetic member may be free or biased to move in the other direction once the actuator is released.

It is desirable to efficiently harvest power when an actuator is used.

Energy harvesting devices are used in many different application scenarios including remote controls which are commonly used devices used to control home appliances.

Typically, remote controls are battery powered, which poses problems for both the user and the environment. Batteries store a finite amount of energy that eventually runs out with use. As the battery discharges, the performance of the device degrades until it eventually stops working. At this stage the batteries must be replaced, which can be a nuisance to the user.

Rechargeable batteries can be used but the recharging process is inefficient, requiring more energy to charge the battery than what is stored. Both types of batteries pose environmental issues - batteries (both rechargeable and non- rechargeable) must be disposed of appropriately, and correct disposal is often left as the responsibility of the user. Unfortunately, not all users have appropriate education about recycling batteries, or time to properly dispose of them, meaning that batteries often end up in landfill and are left to release toxic chemicals into the environment.

An alternative to battery power is to use some form of energy harvesting.

Given that a user must physically press a button to use a remote control, there is a source of mechanical energy that can be harvested from the system using a kinetic energy conversion device of the type discussed above.

Such devices that are currently on the market can generate up to 0.33J in a single motion, which is enough energy to power a small microcontroller and some light emitting diodes ('LEDs'). However, even with this capability, there is a need to further increase power efficiency of energy harvesting in a remote control.

SUMMARY

According to a first aspect of the disclosure, there is provided an energy harvesting device comprising: a first actuator movable by a user between a first position and a second position; an energy conversion device configured to generate electrical energy in an outbound action and a return action; a second actuator that is arranged to selectively initiate the outbound action and/or the return action of the energy conversion device; and wherein: moving the first actuator from the first position to the second position causes the energy conversion device to perform both the outbound action and the return action.

Preferably, the energy conversion device comprise a piezoelectric generator. Alternatively, the energy conversion device comprises a magnetic member and a conductive member arrange to move relative to each other.

Preferably, the energy harvesting device comprises a drive member selectively engageable with the second actuator, and configured to be engaged with the second actuator when the first actuator is in the first position, and disengaged from the second actuator when the first actuator is in the second position.

Preferably, the energy harvesting device is configured such that, in a user actuation event, the drive member remains engaged with the second actuator throughout a first time period when the first actuator moves from the first position up until immediately before it reaches the second position.

Preferably, during the first time period, the second actuator initiates the outbound action of the energy conversion device.

Preferably, the energy harvesting device is configured such that, in a user actuation event, the drive member releases the second actuator when the first actuator reaches the second position.

Preferably, the release of the second actuator enables the return action of the energy conversion device to occur.

Preferably, the drive member comprises a gear member comprising a tooth member which engages with a corresponding drive node on the second actuator.

Preferably, the gear member comprises first and second gear members which each engage with corresponding drive nodes on the second actuator.

Preferably, the energy harvesting device comprises a latch member, having an engaged state in which a force applied to the first actuator urging it from the first position to the second position is transferred to the second actuator and a disengaged state wherein the first actuator is free to move back towards the first position.

Preferably, the energy harvesting device comprises a bias application member that urges the first actuator to its first position, and is released by the latch member when it moves to its disengaged state.

The bias application member may preferably comprise a coil spring or alternatively a torsion spring.

Preferably, the latch member comprises a pawl that engages with a ratchet.

Preferably, the energy harvesting device comprises a tensioning member which urges the pawl towards the ratchet.

Preferably, the energy harvesting device further comprises a selectively engageable retardation member that is configured when engaged to prevent the drive member moving the first actuator in a motion from the second position to the first position.

Preferably, the retardation member comprises an anti-backlash pawl that engages with the ratchet.

Preferably, the drive member and latch member are provided as an integrated unit so that they move together.

The integrated drive member and latch member unit may be formed as a single piece, or may be comprise drive and latch members that are mechanically coupled with each other.

Preferably, the first actuator comprises a pivotable arm that is rotatable about a pivot point.

Preferably, the first actuator comprises a plurality of pivotable arms that are rotatable about separate pivot points. Preferably, the first actuator carries an array of user-operable selection elements.

Preferably, the user-operable selection elements comprise push buttons or capacitive touch sensing elements.

Preferably, the energy conversion device is in electrical communication with the user- operable selection elements and circuitry that is configured to receive and operate on codes or signals generated by the selection elements, wherein operation of any of the user- operable selection elements moves the first actuator from the first position to the second position and the electrical energy generated by the energy conversion device provides power for the operation of the circuitry.

Preferably, the circuitry includes a processor, an energy storage device, and a wireless communications module for sending wireless control signals, most preferably as encoded signals electromagnetically propagated through air.

Preferably, during an activation event the user-operable selection elements are configured to generate a command code before the outbound action of the energy conversion device is initiated.

According to a second aspect of the disclosure, there is provided a method of harvesting energy using an energy conversion device of the type that generates electrical energy in an outbound action and in a return action, said method comprising: moving a first actuator between a first position and a second position; selectively initiating, via a second actuator, the outbound action and/or the return action of the energy conversion device; and wherein: moving the first actuator from the first position to the second position causes the energy conversion device to perform both the outbound action and the return action.

The method of the second aspect may comprise providing or using the apparatus of the first aspect, and may also include other features as described herein. According to a third aspect of the disclosure, there is provided a remote control, provided with an energy harvesting device comprising: a first actuator movable by a user between a first position and a second position; an energy conversion device configured to generate electrical energy in an outbound action and in a return action; a second actuator that is arranged to selectively initiate the outbound action and/or the return action of the energy conversion device; and wherein: moving the first actuator from the first position to the second position causes the energy conversion device to perform both the outbound action and the return action.

The energy harvesting device of the third aspect may comprise any other features of the energy harvesting device of the first aspect and as disclosed elsewhere herein.

According to a fourth aspect of the disclosure, there is provided a method of remotely controlling a device, comprising: providing a remote control device with an energy conversion device of the type that generates electrical energy in an outbound action and in a return action; moving a first actuator between a first position and a second position; and selectively initiating, via a second actuator, the outbound action and/or the return action of the energy conversion device; and wherein: moving the first actuator from the first position to the second position causes the energy conversion device to perform both the outbound action and the return action.

The method of the fourth aspect may comprise providing or using the apparatus of the third aspect, and may also include other features as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 illustrates selected components from an energy harvesting device in accordance with an embodiment of the disclosure;

Figure 2 illustrates exemplary components of an example energy conversion device;

Figure 3 is an exploded diagram showing selected component parts of the device of Figure 1;

Figure 4 illustrates further details of some of the components shown in Figure 3;

Figure 5 and Figure 6 show isometric views of the device of Figure 1;

Figures 7 through 12 illustrate different operational states of the device of Figure 1;

Figure 13 illustrates a system diagram of a remote control device according to the present disclosure;

Figure 14 shows plan view of an exemplary remote control device mechanism;

Figure 15 shows a side view of the remote control device of Figure 13 in a first configuration;

Figure 16 shows a side view of the remote control device of Figure 13 in a second configuration;

Figure 17 shows aspects of an interior design of a remote control;

Figure 18 shows an example exterior housing for a remote control incorporating the energy harvesting system of the disclosure;

Figure 19 shows a first embodiment of an alternative energy harvesting system housed in a remote control device which uses torsion springs; and Figure 20 shows a second embodiment of an energy harvesting system contained within a remote control device using torsion springs and which has a double pivot.

DETAILED DESCRIPTION

It is known to provide an energy conversion device configured to generate electrical energy in an outbound action and in a return action, via piezoelectric generators or upon relative motion of a magnetic member and a conductive member generating electrical energy via the use of electromagnetic induction by moving a permanent magnet through a coil of wire. These types of devices may be known by various names, such as a "kinetic generator" or a "kinetic switch".

There are two actions that generate energy: an outbound action that may comprise pressing the switch mechanism; and a return action that may comprise releasing the switch mechanism, and preferably allowing an internal return mechanism to reset the energy conversion device.

The amount of energy generated depends on the speed at which these two actions occur. In addition, the profile of the generated electrical energy is very impulsive in both directions.

There are therefore at least three problems to solve based on the nature of the energy conversion device.

A first problem is how to transform motion in one direction (the button press) into a press and release motion of the energy conversion device.

This concerns getting the most energy out of system as possible without having to change users' expectations when using a remote: a user would expect the remote to work when the button has been pressed. A direct linkage between the button and the energy conversion device (that is, pressing the button to press the energy conversion device and releasing the button to release the energy conversion device) would miss an opportunity to harvest all the energy available in the process. In particular, a downward pressing action can involve the input of more energy than can be harvested from a single downwards pressing action of the energy conversion device. It is therefore important to get the press-release mechanism of the energy conversion device to work from a single button press.

A second problem is how to make sure the energy conversion device is pressed fast enough by any user at any time so that enough energy is harvested to power the device.

This concerns generating enough energy in a repeatable fashion to power the device. A slow and gentle press and release of the energy conversion device will only generate a small amount of energy, whereas increasing the force and speed of the press will generate more energy. A mechanism to convert a variable button press into a controlled press and release of the energy conversion device is required to make any energy harvesting repeatable.

A third problem is how to make the impulsive electrical energy into a form that is useful.

This concerns how the energy harvested by the energy conversion device is to be used. While existing energy conversion devices can generate significant amounts of energy for small electronic devices, this energy is generated in an extremely short period of time and would dissipate if not controlled. An electronic mechanism to spread out this energy over a longer period is therefore necessary.

The energy conversion device is an expensive component in the bill of materials for a remote control, so it is desirable to make the most effective use of the energy conversion device and ideally to limit the remote control device to utilise a single energy conversion device. There are other challenges related to the implementation of several buttons using one harvester only, including: how to provide a selection of buttons to the user while harvesting the kinetic energy in one place only; • how to make all the buttons have the same push force requirement regardless of where they are located on the remote control; and

• How to make all the buttons meet the requirements of the other three problems mentioned above.

Figure 1 shows an energy harvesting device 100 according to a preferred embodiment of the disclosure. The device includes an energy conversion device 102. A user moves a first actuator (1400, 1402, see Figs. 14-20) between a first position and a second position. In this embodiment, the first position is a rest position and the second position is a "pressed" position. The first actuator (1400, 1402) rests on a second actuator 104 which is used to selectively initiate the outbound action and/or the return action of the energy conversion device 102. The second actuator 104, or activator arm, is urged downwards by a drive member comprising a gear 106 whose teeth engage with corresponding drive nodes of the actuator 104. The device also comprises a latch member comprising a pawl 108 and corresponding ratchet 410 (see Fig. 4). When released from the ratchet 410, the pawl 108 moves back to its rest position under action of a bias application member 114 in the form of a coil spring and pawl return arm 112. An optional retardation member, here in the form of an anti-backlash pawl 116 (though could take alternative forms such as wheel and flexible arm), retards the rotation of the ratchet gear 410 in a reverse direction. In a preferred embodiment, the drive member 106 and ratchet 410 are provided as an integrated unit, as shown in Fig. 4.

It will be appreciated that the present disclosure is not limited to any specific energy conversion device of the type that generates electrical energy upon relative motion of a magnetic member and a conductive member in an outbound action and in a return action. However, as an example, the present embodiment may be used with switch component number AFIG-0007, monostable energy harvesting generator, available from ZF Friedrichshafen AG, aspects of which are illustrated in Figure 2. Here, it can be seen that the energy harvesting switch 102 comprises a double coil with a ferrite core 204 and a magnetic block 206 with sliding plate 208 and an actuating mechanical system with actuator member 210. When an external force is applied to the actuator 210, the magnetic block relocates from an upper position to a lower position generating electrical energy by an induced electromagnetic force in the coil. Then, when the actuator is released the magnetic block returns to its starting neutral position. The motion of the magnetic block returning to its starting neutral position also generates additional electrical energy.

Figure 3 is an exploded diagram illustrating further aspects of the component parts of the energy harvesting system 100 shown in Figure 1. In addition to those parts which are illustrated in Figure 1, Figure 3 further shows a resilient member 118 to bias the antibacklash pawl 116.

Figure 4 shows isometric views of selected components from Figure 3 revealing further detail. The pawl member 108 can be seen as including a pawl pivot 400 and a pawl tensioner 402 and pawl tip 404 that is for engaging with the gear 106 as described in more detail below. The activator arm 104 comprises two push nodes 406 which engage with teeth of the gear 106. In this figure it can also be seen that the gear member 106 comprises a number of portions which may preferably be integrated as a monolithic block but provide different functions. A central portion 410 comprises a plurality of ratchet teeth 412 for engagement with the anti-backlash pawl 116. The gear member 106 further comprises a second gear member which in this embodiment has two outer portions 416 at opposite ends of the assembly where each of the outer portions 416 comprises a plurality of gear push nodes 418 which are arranged for engagement with the corresponding push nodes 406 on the second actuator 104.

Figure 5 shows a flipped underside view of the mechanism showing further details including a pivot point 500 through which a pivot arm 502 is provided, coupling the pawl return arm 112 with the activator arm 104.

Figure 6 shows a further isometric view illustrating a different angle of the same mechanism. During an actuation event, a force is applied to the second actuator 104 in a downward direction. In a rest position the pawl 108 is held against ratchet 410, by the tensioned spring load 110. It will be appreciated that other means of supplying that tension may be used. The ratchet 410 is held and prevented from rotating backwards (anticlockwise in the drawings) by operation or by placement of the anti-backlash pawl 116 which is held in place using a retaining member or spring 118. The second actuator 104 is in a relaxed position and may rest upon an activation switch 210 of the energy harvesting device 102.

Figures 7 through 12 illustrate the functionality of the device 100 showing different operational states as the activator arm is operated. Figure 7 shows a rest state or initial state. The second actuator 104 is pushed downwards when the first actuator 1400, 1402 is pressed downwards. Then (figure 8), the push nodes 406 engage with the corresponding push nodes 418 of the gear member 106. The pawl 108 tip pushes the ratchet tooth 412 downwards, causing the gear 106 to spin clockwise as viewed from the diagram. The resultant action of the ratchet 410 means that the gear push nodes 418 cause the activator arm 104 to press down on the trigger 210 of the energy harvesting device 102. This is then actuated to move the magnetic element of the device 102 and generate a first pulse of energy. It is noted that the pawl tension spring 110 provides a near constant pull force of the pawl tip onto the ratchet. This keeps the system mechanically coupled at all times during any state change preventing the tip of the pole from floating.

Then, as shown in Figure 9, once the trigger 210 of the energy conversion device 102 has been pressed down enough for electrical energy to be generated and released, the tooth 418 of the drive member is at a position corresponding to the maximum lowest extent the corresponding mating push node 406 of the second actuator 104 is at. At this time also the anti-backlash pawl 116 rises over the sawtooth form of the ratchet 410, allowing rotation in one direction only.

As shown in Figure 10, at the energy conversion device 102 release stage, the gear node 418 of the gear member 106 releases the activator arm 210 upwards aided by a force which could be provided by the inherent spring energy stored in the energy harvester 102, or by an additional biasing mechanism that can be used to return the second actuator arm to its starting position. This allows the energy conversion device 102 to generate and release a second burst of energy. Here, the pawl 108 is still in the depressed condition, and the first actuator is at the second, pressed, position and can still in some embodiments move further downwards. Then, as shown in Figure 11, the energy conversion device and second actuator 104 have returned to their rest state.

Figure 12 shows a subsequent pawl return state, in which the pawl 108 is released and returns to its natural rest state, aided by the pawl return springs 114, 110. This is the same as the state shown in Figure 7 and the start/end conditions of the device enable the activation for pressing the next cycle. At this point the anti-backlash pawl or equivalent antirotation device 116 stops the ratchet 410 slipping backwards upon return of the pawl.

An energy harvesting system 100 of the type disclosed herein can be used in a variety of different host devices. One example host device is a remote control. Figure 13 shows a system diagram with the implementation of a remote control. A first actuator 1400, 1402 may comprise an actuator arm which may carry an array of user-operable selection elements, which in this embodiment comprise an array of remote control buttons.

A user interface or keypad 1300 interacts with the energy harvesting device 100 via a mechanical coupling 1302. The energy harvesting system 100 provides an output for a power management unit 1304 which interfaces with a microcontroller 1306 and energy storage device 1308 and provides a drive signal for an illumination device 1310 which may for example comprise an infrared light emitting diode (LED) which sends an infrared (IR) signal to an appliance. It will be appreciated that other system architectures may be employed.

Figure 14 shows a plan view of components for enabling a remote control device according to an embodiment of the invention and which includes an energy harvesting system 100 as seen in Figure 1 and illustrated in Figures 1 through 12.

Here, the activator arm carries a pair of pivot plates 1400, 1402 which themselves are provided with push buttons 1404 for operation by a user of the remote control. In alternative embodiments the push buttons may be replaced by capacitive switches or other capacitive sensing elements on a touchscreen display. Where push buttons 1404 are provided, they may comprise cherry switches or deformable capacitive elements in a known manner.

In this embodiment the first pivot plate 1400 pivots about an axis 1406 and the second pivot plate has a second different pivot point 1408. It will be appreciated in other embodiments that a single pivot plate can be provided.

A single pivot plate may be possible for large or small arrays, but having separate pivot plates with different pivot points enables the device to incorporate a larger array of push buttons 1404 while maintaining a consistent user experience when activating the buttons in use of the remote control device. The pivot plates 1400, 1402 may be coupled together so that if an outer plate is pressed by the user, it carries the inner plate with it.

Figure 15 shows a side view of the device of Figure 14 showing selected components and having alike components illustrated with like reference numerals. It can be seen here that the device can be provided with a stop member 1410 which comprises an indent portion 1500 comprising upper and lower surfaces 1502, 1504 to restrain motion of the pivot plate 1402. Figure 15 also shows tension springs 1505 and 1506 which bias the pivot plates respectively in an upward direction.

Figure 15 shows the device in an initial state ready to receive a button press, while Figure 16 shows the same device with the user having actuated a force to depress the button and rotate the pivot plate 1400, 1402 around their respective pivotable axes. Note that in the rest position the pivot arm 1400 is slightly angled with respect to the pivot arm 1402 and is brought into parallel arrangement with it in the depressed position in Figure 16. It has a bevelled edge that accommodates the relative rotation of one pivot arm with respect to the other.

Figure 17 shows an embodiment of a remote control apparatus 1700 according to the invention. This is a slight variation on the embodiment shown in Figures 15 and 16, as it has a single pivot point, but the energy harvesting system 100 is used within it and has the components as described elsewhere. This is a perspective view showing selected components. It can be seen here that there is a base plate 1702 for attachment of push buttons and other electrical components and an infrared LED 1310 as described elsewhere that sends control signals to remote devices. It can be seen here that the pivot member 1704 can rotate around pivot point 1705 to depress the actuator of the energy harvesting device 102 as described elsewhere.

Figure 18 shows an assembled version of the remote control 1700 showing how a D-pad navigation pad can be provided with user activated buttons 1800 which correspond to the electrical contacts 1706 on the pad 1702.

According to one variation of the invention some of the springs can be replaced by torsion springs as shown in Figures 19 and 20 showing torsion springs 1900 and 1902 for biasing, the main pawl 108 and the return pawl 116 respectively. The embodiment in Figure 19 illustrates a single pivot point 1904 while the embodiment in Figure 20 shows a double pivot 2000 and 2002 for providing separate actuator arms as discussed previously.

It will also be appreciated that the activator arm is only an example of a "first" actuator of the present invention, and that the provision of such an actuator is not limited to remote control devices. Furthermore, it is to be appreciated that the first and second actuators may be provided as a single component, for instance a moulded component with integral hinges that provide similar functionality as described herein.

Various improvements and modifications can be made to the above without departing from the scope of the invention.

Claims

1. An energy harvesting device comprising: a first actuator movable by a user between a first position and a second position; an energy conversion device configured to generate electrical energy in an outbound action and a return action; a second actuator that is arranged to selectively initiate the outbound action and/or the return action of the energy conversion device; a drive member driven by the first actuator and selectively engageable with the second actuator, further in which the drive member is configured to be engaged with the second actuator when the first actuator is in the first position, and to become disengaged from the second actuator when the first actuator is in the second position; and wherein: moving the first actuator from the first position to the second position causes the drive member to engage with the second actuator and to disengage from the second actuator when the first actuator is in the second position, and the energy conversion device to perform both the outbound action and the return action.

2. The energy harvesting device of claim 1, wherein the energy conversion device comprises a piezoelectric generator.

3. The energy harvesting device of claim 1, wherein the energy conversion device comprises a magnetic member and a conductive member arrange to move relative to each other.

4. The energy harvesting device of any preceding claim, configured such that, in a user actuation event, the drive member remains engaged with the second actuator throughout a first time period when the first actuator moves from the first position up until immediately before it reaches the second position.

5. The energy harvesting device of claim 4, wherein, during the first time period, the second actuator initiates the outbound action of the energy conversion device.

6. The energy harvesting device of any preceding claim, configured such that, in a user actuation event, the drive member releases the second actuator when the first actuator reaches the second position.

7. The energy harvesting device of claim 6, wherein the release of the second actuator enables the return action of the energy conversion device to occur.

8. The energy harvesting device of any preceding claim, wherein the drive member comprises a gear member comprising a tooth member which engages with a corresponding drive node on the second actuator.

9. The energy harvesting device of claim 8, wherein the gear member comprises first and second gear members which each engage with corresponding drive nodes on the second actuator.

10. The energy harvesting device of any preceding claim, comprising a latch member, having an engaged state in which a force applied to the first actuator urging it from the first position to the second position is transferred to the second actuator and a disengaged state wherein the first actuator is free to move back towards the first position.

11. The energy harvesting device of claim 10, wherein the energy harvesting device comprises a bias application member that urges the first actuator to its first position, and is released by the latch member when it moves to its disengaged state.

12. The energy harvesting device of claim 11, wherein the bias application member comprises a coil spring or alternatively a torsion spring.

13. The energy harvesting device of claim any of claims 10 to 12, wherein the latch member comprises a pawl that engages with a ratchet.

14. The energy harvesting device of claim 13, wherein the energy harvesting device comprises a tensioning member which urges the pawl towards the ratchet.

15. The energy harvesting device of any preceding claim, further comprising a selectively engageable retardation member that is configured when engaged to prevent the drive member moving the first actuator in a motion from the second position to the first position.

16. The energy harvesting device of claim 15, wherein the retardation member comprises an anti-backlash pawl that engages with the ratchet.

17. The energy harvesting device of any of claims 10 to 16, wherein the drive member and latch member are provided as an integrated unit so that they move together.

18. The energy harvesting device of any preceding claim, wherein the first actuator comprises a pivotable arm that is rotatable about a pivot point.

19. The energy harvesting device of any preceding claim, wherein the first actuator comprises a plurality of pivotable arms that are rotatable about separate pivot points.

20. The energy harvesting device of any preceding claim, wherein the first actuator carries an array of user-operable selection elements, which comprise push buttons or capacitive touch sensing elements.

21. The energy harvesting device of claim 20, wherein the energy conversion device is in electrical communication with the user-operable selection elements and circuitry that is configured to receive and operate on codes or signals generated by the selection elements, wherein operation of any of the user-operable selection elements moves the first actuator from the first position to the second position and the electrical energy generated by the energy conversion device provides power for the operation of the circuitry.

22. The energy harvesting device of claim 21, wherein the circuitry includes a processor, an energy storage device, and a wireless communications module for sending wireless control signals, most preferably as encoded signals electromagnetically propagated through air.

23. The energy harvesting device of any of claims 20 to 22, wherein, during an activation event the user-operable selection elements are configured to generate a command code before the outbound action of the energy conversion device is initiated.

24. A method of harvesting energy using an energy conversion device of the type that generates electrical energy in an outbound action and in a return action, said method comprising: moving a first actuator between a first position and a second position; selectively initiating, via a second actuator, the outbound action and/or the return action of the energy conversion device; selectively engaging a drive member driven by the first actuator with the second actuator as the first actuator moves from the first position to the second position, and disengaging the drive member from the second actuator when the first actuator is in the second position; and wherein: moving the first actuator from the first position to the second position causes the drive member to engage with the second actuator and to disengage from the second actuator when the first actuator is in the second position, and the energy conversion device to perform both the outbound action and the return action.

25. A remote control, provided with an energy harvesting device comprising: a first actuator movable by a user between a first position and a second position; an energy conversion device configured to generate electrical energy in an outbound action and in a return action; a second actuator that is arranged to selectively initiate the outbound action and/or the return action of the energy conversion device; a drive member driven by the first actuator selectively engageable with the second actuator, and configured to be engaged with the second actuator when the first actuator is in the first position, and to become disengaged from the second actuator when the first actuator is in the second position; and wherein: moving the first actuator from the first position to the second position causes the drive member to engage with the second actuator and to disengage from the second actuator when the first actuator is in the second position, and the energy conversion device to perform both the outbound action and the return action.

26. A method of remotely controlling a device, comprising: providing a remote control device with an energy conversion device of the type that generates electrical energy in an outbound action and in a return action; moving a first actuator between a first position and a second position; and selectively initiating, via a second actuator, the outbound action and/or the return action of the energy conversion device; selectively engaging a drive member driven by the first actuator with the second actuator as the first actuator moves from the first position to the second position, and disengaging the drive member from the second actuator when the first actuator is in the second position; and wherein: moving the first actuator from the first position to the second position causes the drive member to engage with the second actuator and to disengage from the second actuator when the first actuator is in the second position, and the energy conversion device to perform both the outbound action and the return action.