CROSS REFERENCES TO RELATED APPLICATIONS

This application is related to and claims priority from commonly owned US Provisional Patent Application Serial Number 62/567,770, entitled: Method, Product, and Technology for Charging a Cellular Phone and Products", filed on October 4, 2017, the disclosure of which is incorporated by reference in its entirety herein.

TECHNICAL FIELD

This invention relates to portable electronic devices requiring electrical power for their operation and specifically to those powered by harvesting kinetic energy.

BACKGROUND OF INVENTION

A portable electronic device, such as an electronic wristwatch, a media player (e.g. iPod), an electronic book, or a cellphone, typically contains one or more electrical batteries which supply the electrical power requirements of the device, hi the course of use, the batteries !ose power and must be replaced or recharged periodically; otherwise, the portable device stops working. Normally, this requires suspending portable operation of the device for a long period of time; for example, by physically attaching it to a separate electronic charger plugged into an electrical wall outlet.

US Patent Number 4,213,292, to Dotezal et al., entitled "Thetmoelectrically- powered wrist watch", dated July 22, 1980, discloses a thermoelectrically-powered wrist watch in which thermal energy is picked up by the metal back of the watch casing, and is transferred to the hot pole of an electro- thermal generator. The source of the thermal energy is the body heat of the wearer, whose body temperature is nominally 37 degrees Celsius, Thus, thermoelectric power is available only when the watch is attached to the wrist of the wearer and the ambient air temperature is less than 37 degrees Celsius.

Furthermore, the amount of thermal power available is proportional to the area of the watch casing in contact with the wrist of the wearer, which, for a round casing with a radius of two centimeters is only 12.6 square centimeters. The maximum amount of thermoelectric power available in this case is at most a few milliwatts. This is insufficient for modem portable devices requiring at least 500 milliwatts of time-averaged power, in order to operate indefinitely without interruption.

US Patent Number 8487456, to Donelan et al, entitled "Methods and Apparatus for Harvesting Biomechanicai Energy ^" , dated July 16, 2013, discloses methods and apparatus for harvesting energy from motion of one or more joints comprising a generator, one or more sensors, and control circuitry. Some embodiments include a roller clutch and a gear mechanism, which converts high-torque, low-speed mechanical power to high-speed, low-torque mechanical power. The latter is better suited as input to a generator, such as a rotary-magnetic brushless DC motor, Although this approach can deliver relatively large amounts of electrical power, it is overly cumbersome for many applications involving portable electronic devices,

US Patent Application Number 12/288926 to Leukkunen, entitled "Kinetic Harvesting Frequency Optimizer', filed on October 24, 2008, discloses an apparatus with a kinetic energy scavenger mechanism and a frequency tuning system. The kinetic energy scavenger mechanism harvests energy from a movement of a portable device and includes at least one piezo member. The frequency tuning system tunes the harv esting frequency of the at least one piezo member.

International Patent Application Number PCT/US2012/038348 to Wang et al, entitled "Nanogenerator for Self-Powered System with Wireless Data Transmission", filed on May 17, 2012, discloses a generator having a first electrode layer, a dense plurality of vertically-aligned piezoelectric elongated nanostructures, an insulating layer and a second electrode layer. One application is to neuro-proslhetics that harvest biomechanicai energy which exists in the human body in the form of muscle contractions.

US Patent Application Number 15/159,225, to Wang et al,, entitled 'Triboelectric Nanogenerator for Harvesting Broadband Kinetic Impact Energy", filed on May 19, 2016. discloses a triboelectric generator having a first triboelectric member, which includes a first conductive layer and an insulating triboelectric material layer having a first position on a triboelectric series; and an elastic member, which includes a second conductive material having a second position on the triboelectric series. Ambient mechanical energy is harvested by compressing and then releasing the elastic member, thereby causing electrical charges to flow between the first conductive layer and the second conductive layer, through- an. electrical load,, such as a battery.

The above-mentioned prior arts do not fulfill the need for power generation, at a time-averaged power level of 500 milliwatts or more, in a compact physical form factor, that is suitable for portable electronic devices.

SUMMARY OF THE INVENTION

The present invention discloses a portable electronic device powered by kinetic energy harvesting, which overcomes the deficiencies of the prior art with regard to time-averaged power and physical form factor.

The portable electronic device of the present, invention includes a rechargeable battery, a nano-kinetic energy array consisting of a multiplicity of nano-kinetic energy transducers, and a power combiner. The nano-kinetic energy transducers convert random mechanical vibrations from the ambient environment into electrical power; and the power combiner sums the electrical power of all the transducers, and outputs it to the rechargeable battery.

According to one feature of certain preferred implementations of the portable electronic device, each of the nano-kinetic energy transducers includes an electricity generator, a suspension, and a pedestal.

According to another feature of certain preferred implementations of the portable electronic device, the suspension is made of an elastic material, such as . Phosphor Bronze, spring steel, or Beryllium Copper.

According to yet another feature of certain preferred implementations of the portable electronic device, the nano-kinetic energy transducers have approximately the same resonant vibrational frequency.

According to still another feature of certain preferred implementations of the portable electronic device, the nano-kinetic energy transducers have substantially different resonant vibrational frequencies.

According to a further feature of certain preferred implementations- of the portable electronic device, at least one of the nano-kinetic energy transducers has a resonant vibrational frequency which is less than or equal to 60 hertz. According to another feature of certain preferred implementations of the portable electronic device, at least one of the nano-kinetic energy transducers includes an electromagnetic electricity generator,

According to yet another feat ure of certain preferred implementations of the portable electronic device, the electromagnetic electricity generator includes a body comprised of magnetic material, a spring, and one or more conducting coils.

According to still another feature of certain preferred implementations of the portable electronic device, at least one of the nano-kinetic energy transducers includes a piezoelectric electricity generator.

According to a further feature of certain preferred implementations of the portable electronic device, at least one of the nano-kinetic energy transducers includes a triboelectric electricity generator.

According to another feature of certain preferred implementations of the portable electronic device, the nano-kinetic energy array has a rectangular geometry.

According to yet another feature of certain preferred implementations of the portable electronic device, the nano-kinetic energy array has a hexagonal geometry.

According to still another feature of certain preferred implementations of the portable electronic device, the nano-kinetic energy array includes at least one thousand nano-kinetic energy transducers.

According to a further feature of certain preferred implementations of the portable electronic device, the power combiner includes at least one two-to-one power combiner.

According to another feature of certain preferred implementations of the portable electronic device, the two-to-one power combiner is a Wilkinson power combiner.

According to yet another feature of certain preferred implementations of the portable electronic device, the volume occupied by at least one of the nano-kinetic energy transducers is less than or equal to 0.04 cubic centimeters.

According to yet another feature of certain preferred implementations of the portable electronic device, the volume occupied by at least one of the nano-kinetic energy transducers is greater than or equal to 0.004 cubic centimeters. BRIEF DESCRIPTION OF THE FIGURES

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:

FIG. 1A is a drawing showing a prior-art portable electronic device, as viewed from the back,

FIG. IB is a drawing showing the prior-art portable electronic device of FIG. I A, as viewed from the side.

FIG. 2A is a drawing showing an exemplary portable electronic device according to an embodiment of the i nvention, as view ed from the back.

FIG. 2B is a drawing showing the exemplary portable electronic device of FIG, 2A, as viewed from the side.

FIG. 3 is a drawing showing an exemplary nano-kinetic energy transducer according to an embodiment of the invention.

FIG. 4(a) is a piciure showing an exemplary nano-kinetic energy transducer according to an embodiment of the invention.

FIG. 4(b) is a picture showing a multiplicity of exemplary nano-kinetic energy transducers according to an embodiment of the invention.

FIG. 5 is a picture showing a portion of an exemplary nano-kinetic energy array according to an embodiment of the invention.

FIG. 6 is a drawing showing an exemplary power combiner according to an embodiment of the invention.

FIG. 7 is a drawing showing an exemplary electricity generator according to an embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is a portable electronic device powered by kinetic energy harvesting. The principles of the present invention may be better understood with reference to the drawings and the accompanying description.

FIG. 1 A shows a prior-art portable electronic device 100, as viewed from the back, with all protective covers removed. Device 100 is similar to many of the so- called "smartphones" currently manufactured by Apple, Samsung, LG Electronics, Xiaomi, Huawei, and others. Back face 1 10 of device 100 includes a variety of modules requiring electrical power, such as camera 150, camera flash 155, and speaker 170. Back face 1 10 also includes a memory card 160 and a subscriber identification module (SIM) card 165, winch are connected to internal electronic circuitry (not shown). Volume control 175 protrudes from the side of device 100.

Electrical power is supplied by rechargeable battery 120 which rests inside battery compartment 1 15, and connects to internal electronic circuitry by means of positive spring contact 140 and negative spring contact 145, The battery is recharged periodically by connecting an external battery charger to battery charger connection 130. Connection 130 is in electrical contact with a charging protection circuit 125, which is part of the internal electronic circuitry of device 100. The dotted line surrounding circuit 125 indicates that it is not directly visible from the back of device 100. in an exemplary embodiment, battery 120 is a Lithium-ion rechargeable battery having a nominal voltage of 3,7 V, a capacity of about 3 ampere-hours (Ah), and a total stored energy of about 40,000 Joules (J). The volume and weight of the battery are typically about 20 cubic centimeters (cc) and 50 grams (g), respectively. The dimensions of battery compartment 1 15 are roughly 5 cm wide by 8 cm long by 0.5 cm thick. When the battery is fully charged, device 100 can operate for approximately 24 hours without recharging.

FIG. I B is a side view of device 100, showing front face 105 and back face 1 10, The separation distance between the two faces is typically about 0.8 cm.

FIG. 2A shows an exemplary portable electronic device 200 according to an embodiment of the invention, as viewed from the back. Like reference numbers correspond to those of FIG. 1 A. Nano-kinetic energy array 215 completely covers the area (A) of battery compartment 1 15, whose value is approximately 5 cm multiplied by 8 cm, or 40 square cm.

Nano-kinetic energy array 215 consists of a large number (N) of individual nano-kinetic energy transducers 230. Each transducer 230 occupies an area (Al) equal to A/N. and produces a time-averaged electrical power, denoted by (PI), using the power from ambient random mechanical vibrations. For example, in a preferred embodiment, N, Al, and PI are equal to 1024, 0.04 square cm., and 0.5 mW, respectively.

Power combiner 240 is an electrical circuit which combines the electrical power provided by all N transducers 230 into a single total power output. The combined electrical power at the output of power combiner 240 is slightly less man N times PI, owing to thermal losses. For the abovementioned preferred embodiment, N times PI is approximately 500 mW.

FIG. 2B shows an exemplary portable electronic device 200 according to an embodiment of the invention, as viewed from the side. Nano-kinetic energy array 215 and power combiner 240 protrude from back face 110 by approximately 0.5 cm.

FIG. 3 shows an exemplary nano-kinetic energy transducer 230 according to an embodiment of the invention. Electricity generator 232 is in mechanical contact with suspension 234, which is in contact with pedestal 236. In response to ambient random mechanical vibrations, pedestal 236 is set into motion. The motion is amplified by suspension 234 and transmitted to electricity generator 232. The latter vibrates with a time-varying acceleration, a(t), and produces a time-varying electrical current, i(t).

Pedestal 236 may be any convenient shape, for example, rectangular or trapezoidal. Suspension 234 is preferably made of a highly elastic material, such as Phosphor Bronze, spring steel, or Beryllium Copper. The latter materials also conduct electricity, and therefore may serve the added function of conducting the electrical current, i(t), to pedestal 236. If non-conducting elastic material is used for suspension 234, an additional copper wire maybe needed to conduct electrical current through suspension 234. The total volume occupied by nano-kinetic energy transducer 230 is approximately the area A3 multiplied by a thickness (T), as shown in FIG. 3. In the above-mentioned preferred embodiment having A l- 04 square cm., thickness (T) is typically between 0.1 cm and 1.0 cm. The volume of transducer 230 is then between 0.004 and .04 cubic cm. (cc). For the case PI =0.5 mW, the electrical power density provided by nano-kinetic energy transducer 230 is between 12.5 and 125 mW/cc. This range of electrical power density is achievable by those skilled in the art of kinetic energy harvesting.

FIG. 4(a) and FIG. 4(b) are actual pictures showing a single exemplary nano- kinetic energy transducer and a multiplicity of exemplary nano-kinetic energy transducers, respectively, according to an embodiment of the invention.

FIG. 5 is a picture showing a portion of an exemplary nano-kinetic energy array according to an embodiment of the invention. The array in FIG. 5 has a rectangular geometry, however other geometries, such as hexagonal, may be used to increase the number of transducers per unit area. The dimensions Dl and D2 indicated in the picture may or may not be equal. These two dimensions must, be large enough to avoid contact between adjacent nano-kinetic energy transducers, under the most extreme ambient vibration scenarios. Typical values of Dl and 02 range from 0.1 to 0.5 cm.

FIG. 6 is a drawing showing the structure of power combiner 240, In a preferred embodiment, power combiner 240 is comprised of a multiplicity of two-to- one power combiners 245 arranged in stages, as shown in FIG. 6, In the first stage, each two-to-one power combiner sums the output power of two individual nano- kinetic energy transducers 230, and delivers the combined power to the next stage- Thus, at each stage, the number of power signals requiring combination is reduced by a. factor of two. After log ₂ ( N), stages, the output signal contains the power of all N nano-kinetic energy transducers 230. An exemplary two-to-one power combiner is the so-called Wilkinson power combiner, which is known to those skilled in the art of electrical circuit design,

FIG. 7 shows an exemplary electricity generator 232 according to an embodiment of the invention, which employs electromagnetic induction. Body 250 is preferably made of a highly magnetic material such as Neodymium Iron Boron (NdFeB) bonded to a high-density material, such as a tungsten alloy having a density of about 18 g/ec. Body 250 is connected to spring 255 and oscillates in response to time-varying motion of pedestal 236 caused by ambient random ^■ mechanical vibrations. Conducting coils 260 are preferably made of copper or aluminum. The movement of body 250 inside conducting coils 260 gives rise to an induced electromotive force (emf). The induced emf produces a time-varying electrical current that is conducted out of nano-kinetic energy transducer 230 and into power combiner 240.

In FIG. 7, the resonant vibrational frequency (F) of body 250 is approximately equal to the square root of (K/M) divided by 2π, where (K) is the force constant of spring 255 and M is the mass of body 250 in grams. By selecting the values of K. and M, one may adjust the resonant vibrational frequency (F) to match the irequency of ambient random mechanical vibrations having the most energy. In a preferred embodiment, M, K, and F are equal to 0.1 gram, ] 4000 dynes/cm, and 60 hertz (Hz), respectively.

In an alternative embodiment of nano-kinetic energy array 215, the nano-kinetic energy transducers 230 may be designed to have substantially different resonant vibrational frequencies. This is especially advantageous in environments where the ambient random mechanical vibrations extend over a wide range of different frequencies.

It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims. For example, the exemplary electricity generator of FIG. 7 may be replaced by one based upon alternative power harvesting technologies, that employ piezoelectric and/or triboelectric materials. Such technologies are known to those skilled in the art of kinetic energy harvesting.

Furthermore, although a cellphone has been used for illustrative purposes in this disclosure, many other portable electronic devices may benefit from the kinetic energy harvesting principles and innovations disclosed herein.