Patent Publication Number: US-2011056215-A1

Title: Wireless power for heating or cooling

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §119 
     This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/241,337 entitled “WIRELESSLY POWERED HEATING OR COOLING” filed on Sep. 10, 2009, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     The present invention relates generally to wireless power, and more specifically to thermoelectric cooling or heating via wireless power. 
     2. Background 
     Typically, each battery powered device requires its own charger and power source, which is usually an AC power outlet. This becomes unwieldy when many devices need charging. 
     Approaches are being developed that use over-the-air power transmission between a transmitter and the device to be charged. These generally fall into two categories. One is based on the coupling of plane wave radiation (also called far-field radiation) between a transmit antenna and receive antenna on the device to be charged which collects the radiated power and rectifies it for charging the battery. Antennas are generally of resonant length in order to improve the coupling efficiency. This approach suffers from the fact that the power coupling falls off quickly with distance between the antennas. So charging over reasonable distances (e.g., &gt;1-2m) becomes difficult. Additionally, since the system radiates plane waves, unintentional radiation can interfere with other systems if not properly controlled through filtering. 
     Other approaches are based on inductive coupling between a transmit antenna embedded, for example, in a “charging” mat or surface and a receive antenna plus rectifying circuit embedded in the host device to be charged. This approach has the disadvantage that the spacing between transmit and receive antennas must be very close (e.g. mms). Though this approach does have the capability to simultaneously charge multiple devices in the same area, this area is typically small, hence the user must locate the devices to a specific area. 
     Wireless power transfer may find other applications in addition to charging a power storage device. Accordingly, there are other needs for systems, methods and devices that utilize transmitted wireless power to accomplish other desirable outcomes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a simplified block diagram of a wireless power transfer system. 
         FIG. 2  shows a simplified schematic diagram of a wireless power transfer system. 
         FIG. 3  illustrates a schematic diagram of a loop antenna for use in exemplary embodiments of the present invention. 
         FIG. 4  is a simplified block diagram of a transmitter, in accordance with an exemplary embodiment of the present invention. 
         FIG. 5  is a simplified block diagram of a receiver, in accordance with an exemplary embodiment of the present invention. 
         FIG. 6  shows a simplified schematic of a portion of transmit circuitry for carrying out messaging between a transmitter and a receiver. 
         FIG. 7  depicts a wireless power system, in accordance with an exemplary embodiment of the present invention. 
         FIG. 8  is a block diagram of a wireless power system including a wireless power device and a plurality of devices positioned thereon. 
         FIG. 9  is a block diagram of another wireless power system including a wireless power device and a plurality of devices positioned thereon. 
         FIG. 10  illustrates a device positioned on a surface of a display device, according to an exemplary embodiment of the present invention. 
         FIG. 11  illustrates another positioned on a surface of a display device, in accordance with an exemplary embodiment of the present invention. 
         FIG. 12  is a flowchart illustrating a method, in accordance with an exemplary embodiment of the present invention. 
         FIG. 13  is a flowchart illustrating another method, in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention can be practiced. The term “exemplary” used throughout this description means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other exemplary embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary embodiments of the invention. It will be apparent to those skilled in the art that the exemplary embodiments of the invention may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the novelty of the exemplary embodiments presented herein. 
     The words “wireless power” is used herein to mean any form of energy associated with electric fields, magnetic fields, electromagnetic fields, or otherwise that is transmitted between from a transmitter to a receiver without the use of physical electromagnetic conductors. 
       FIG. 1  illustrates a wireless transmission or charging system  100 , in accordance with various exemplary embodiments of the present invention. Input power  102  is provided to a transmitter  104  for generating a radiated field  106  for providing energy transfer. A receiver  108  couples to the radiated field  106  and generates an output power  110  for storing or consumption by a device (not shown) coupled to the output power  110 . Both the transmitter  104  and the receiver  108  are separated by a distance  112 . In one exemplary embodiment, transmitter  104  and receiver  108  are configured according to a mutual resonant relationship and when the resonant frequency of receiver  108  and the resonant frequency of transmitter  104  are very close, transmission losses between the transmitter  104  and the receiver  108  are minimal when the receiver  108  is located in the “near-field” of the radiated field  106 . 
     Transmitter  104  further includes a transmit antenna  114  for providing a means for energy transmission and receiver  108  further includes a receive antenna  118  for providing a means for energy reception. The transmit and receive antennas are sized according to applications and devices to be associated therewith. As stated, an efficient energy transfer occurs by coupling a large portion of the energy in the near-field of the transmitting antenna to a receiving antenna rather than propagating most of the energy in an electromagnetic wave to the far field. When in this near-field a coupling mode may be developed between the transmit antenna  114  and the receive antenna  118 . The area around the antennas  114  and  118  where this near-field coupling may occur is referred to herein as a coupling-mode region. 
       FIG. 2  shows a simplified schematic diagram of a wireless power transfer system. The transmitter  104  includes an oscillator  122 , a power amplifier  124  and a filter and matching circuit  126 . The oscillator is configured to generate a signal at a desired frequency, which may be adjusted in response to adjustment signal  123 . The oscillator signal may be amplified by the power amplifier  124  with an amplification amount responsive to control signal  125 . The filter and matching circuit  126  may be included to filter out harmonics or other unwanted frequencies and match the impedance of the transmitter  104  to the transmit antenna  114 . 
     The receiver  108  may include a matching circuit  132  and a rectifier and switching circuit  134  to generate a DC power output to charge a battery  136  as shown in  FIG. 2  or power a device coupled to the receiver (not shown). The matching circuit  132  may be included to match the impedance of the receiver  108  to the receive antenna  118 . The receiver  108  and transmitter  104  may communicate on a separate communication channel  119  (e.g., Bluetooth, zigbee, cellular, etc). 
     As illustrated in  FIG. 3 , antennas used in exemplary embodiments may be configured as a “loop” antenna  150 , which may also be referred to herein as a “magnetic” antenna. Loop antennas may be configured to include an air core or a physical core such as a ferrite core. Air core loop antennas may be more tolerable to extraneous physical devices placed in the vicinity of the core. Furthermore, an air core loop antenna allows the placement of other components within the core area. In addition, an air core loop may more readily enable placement of the receive antenna  118  ( FIG. 2 ) within a plane of the transmit antenna  114  ( FIG. 2 ) where the coupled-mode region of the transmit antenna  114  ( FIG. 2 ) may be more powerful. 
     As stated, efficient transfer of energy between the transmitter  104  and receiver  108  occurs during matched or nearly matched resonance between the transmitter  104  and the receiver  108 . However, even when resonance between the transmitter  104  and receiver  108  are not matched, energy may be transferred at a lower efficiency. Transfer of energy occurs by coupling energy from the near-field of the transmitting antenna to the receiving antenna residing in the neighborhood where this near-field is established rather than propagating the energy from the transmitting antenna into free space. 
     The resonant frequency of the loop or magnetic antennas is based on the inductance and capacitance. Inductance in a loop antenna is generally simply the inductance created by the loop, whereas, capacitance is generally added to the loop antenna&#39;s inductance to create a resonant structure at a desired resonant frequency. As a non-limiting example, capacitor  152  and capacitor  154  may be added to the antenna to create a resonant circuit that generates resonant signal  156 . Accordingly, for larger diameter loop antennas, the size of capacitance needed to induce resonance decreases as the diameter or inductance of the loop increases. Furthermore, as the diameter of the loop or magnetic antenna increases, the efficient energy transfer area of the near-field increases. Of course, other resonant circuits are possible. As another non-limiting example, a capacitor may be placed in parallel between the two terminals of the loop antenna. In addition, those of ordinary skill in the art will recognize that for transmit antennas the resonant signal  156  may be an input to the loop antenna  150 . 
       FIG. 4  is a simplified block diagram of a transmitter  200 , in accordance with an exemplary embodiment of the present invention. The transmitter  200  includes transmit circuitry  202  and a transmit antenna  204 . Generally, transmit circuitry  202  provides RF power to the transmit antenna  204  by providing an oscillating signal resulting in generation of near-field energy about the transmit antenna  204 . By way of example, transmitter  200  may operate at the 13.56 MHz ISM band. 
     Exemplary transmit circuitry  202  includes a fixed impedance matching circuit  206  for matching the impedance of the transmit circuitry  202  (e.g., 50 ohms) to the transmit antenna  204  and a low pass filter (LPF)  208  configured to reduce harmonic emissions to levels to prevent self-jamming of devices coupled to receivers  108  ( FIG. 1 ). Other exemplary embodiments may include different filter topologies, including but not limited to, notch filters that attenuate specific frequencies while passing others and may include an adaptive impedance match, that can be varied based on measurable transmit metrics, such as output power to the antenna or DC current draw by the power amplifier. Transmit circuitry  202  further includes a power amplifier  210  configured to drive an RF signal as determined by an oscillator  212 . The transmit circuitry may be comprised of discrete devices or circuits, or alternately, may be comprised of an integrated assembly. An exemplary RF power output from transmit antenna  204  may be on the order of 2.5 Watts. 
     Transmit circuitry  202  further includes a controller  214  for enabling the oscillator  212  during transmit phases (or duty cycles) for specific receivers, for adjusting the frequency of the oscillator, and for adjusting the output power level for implementing a communication protocol for interacting with neighboring devices through their attached receivers. 
     The transmit circuitry  202  may further include a load sensing circuit  216  for detecting the presence or absence of active receivers in the vicinity of the near-field generated by transmit antenna  204 . By way of example, a load sensing circuit  216  monitors the current flowing to the power amplifier  210 , which is affected by the presence or absence of active receivers in the vicinity of the near-field generated by transmit antenna  204 . Detection of changes to the loading on the power amplifier  210  are monitored by controller  214  for use in determining whether to enable the oscillator  212  for transmitting energy to communicate with an active receiver. 
     Transmit antenna  204  may be implemented as an antenna strip with the thickness, width and metal type selected to keep resistive losses low. In a conventional implementation, the transmit antenna  204  can generally be configured for association with a larger structure such as a table, mat, lamp or other less portable configuration. Accordingly, the transmit antenna  204  generally will not need “turns” in order to be of a practical dimension. An exemplary implementation of a transmit antenna  204  may be “electrically small” (i.e., fraction of the wavelength) and tuned to resonate at lower usable frequencies by using capacitors to define the resonant frequency. In an exemplary application where the transmit antenna  204  may be larger in diameter, or length of side if a square loop, (e.g., 0.50 meters) relative to the receive antenna, the transmit antenna  204  will not necessarily need a large number of turns to obtain a reasonable capacitance. 
     The transmitter  200  may gather and track information about the whereabouts and status of receiver devices that may be associated with the transmitter  200 . Thus, the transmitter circuitry  202  may include a presence detector  280 , an enclosed detector  290 , or a combination thereof, connected to the controller  214  (also referred to as a processor herein). The controller  214  may adjust an amount of power delivered by the amplifier  210  in response to presence signals from the presence detector  280  and the enclosed detector  290 . The transmitter may receive power through a number of power sources, such as, for example, an AC-DC converter (not shown) to convert conventional AC power present in a building, a DC-DC converter (not shown) to convert a conventional DC power source to a voltage suitable for the transmitter  200 , or directly from a conventional DC power source (not shown). 
     As a non-limiting example, the presence detector  280  may be a motion detector utilized to sense the initial presence of a device to be charged that is inserted into the coverage area of the transmitter. After detection, the transmitter may be turned on and the RF power received by the device may be used to toggle a switch on the Rx device in a pre-determined manner, which in turn results in changes to the driving point impedance of the transmitter. 
     As another non-limiting example, the presence detector  280  may be a detector capable of detecting a human, for example, by infrared detection, motion detection, or other suitable means. In some exemplary embodiments, there may be regulations limiting the amount of power that a transmit antenna may transmit at a specific frequency. In some cases, these regulations are meant to protect humans from electromagnetic radiation. However, there may be environments where transmit antennas are placed in areas not occupied by humans, or occupied infrequently by humans, such as, for example, garages, factory floors, shops, and the like. If these environments are free from humans, it may be permissible to increase the power output of the transmit antennas above the normal power restrictions regulations. In other words, the controller  214  may adjust the power output of the transmit antenna  204  to a regulatory level or lower in response to human presence and adjust the power output of the transmit antenna  204  to a level above the regulatory level when a human is outside a regulatory distance from the electromagnetic field of the transmit antenna  204 . 
     As a non-limiting example, the enclosed detector  290  (may also be referred to herein as an enclosed compartment detector or an enclosed space detector) may be a device such as a sense switch for determining when an enclosure is in a closed or open state. When a transmitter is in an enclosure that is in an enclosed state, a power level of the transmitter may be increased. 
     In exemplary embodiments, a method by which the transmitter  200  does not remain on indefinitely may be used. In this case, the transmitter  200  may be programmed to shut off after a user-determined amount of time. This feature prevents the transmitter  200 , notably the power amplifier  210 , from running long after the wireless devices in its perimeter are fully charged. This event may be due to the failure of the circuit to detect the signal sent from either the repeater or the receive coil that a device is fully charged. To prevent the transmitter  200  from automatically shutting down if another device is placed in its perimeter, the transmitter  200  automatic shut off feature may be activated only after a set period of lack of motion detected in its perimeter. The user may be able to determine the inactivity time interval, and change it as desired. As a non-limiting example, the time interval may be longer than that needed to fully charge a specific type of wireless device under the assumption of the device being initially fully discharged. 
       FIG. 5  is a simplified block diagram of a receiver  300 , in accordance with an exemplary embodiment of the present invention. The receiver  300  includes receive circuitry  302  and a receive antenna  304 . Receiver  300  further couples to device  350  for providing received power thereto. It should be noted that receiver  300  is illustrated as being external to device  350  but may be integrated into device  350 . Generally, energy is propagated wirelessly to receive antenna  304  and then coupled through receive circuitry  302  to device  350 . 
     Receive antenna  304  is tuned to resonate at the same frequency, or near the same frequency, as transmit antenna  204  ( FIG. 4 ). Receive antenna  304  may be similarly dimensioned with transmit antenna  204  or may be differently sized based upon the dimensions of the associated device  350 . By way of example, device  350  may be a portable electronic device having diametric or length dimension smaller that the diameter of length of transmit antenna  204 . In such an example, receive antenna  304  may be implemented as a multi-turn antenna in order to reduce the capacitance value of a tuning capacitor (not shown) and increase the receive antenna&#39;s impedance. By way of example, receive antenna  304  may be placed around the substantial circumference of device  350  in order to maximize the antenna diameter and reduce the number of loop turns (i.e., windings) of the receive antenna and the inter-winding capacitance. 
     Receive circuitry  302  provides an impedance match to the receive antenna  304 . Receive circuitry  302  includes power conversion circuitry  306  for converting a received RF energy source into charging power for use by device  350 . Power conversion circuitry  306  includes an RF-to-DC converter  308  and may also in include a DC-to-DC converter  310 . RF-to-DC converter  308  rectifies the RF energy signal received at receive antenna  304  into a non-alternating power while DC-to-DC converter  310  converts the rectified RF energy signal into an energy potential (e.g., voltage) that is compatible with device  350 . Various RF-to-DC converters are contemplated, including partial and full rectifiers, regulators, bridges, doublers, as well as linear and switching converters. 
     Receive circuitry  302  may further include switching circuitry  312  for connecting receive antenna  304  to the power conversion circuitry  306  or alternatively for disconnecting the power conversion circuitry  306 . Disconnecting receive antenna  304  from power conversion circuitry  306  not only suspends charging of device  350 , but also changes the “load” as “seen” by the transmitter  200  ( FIG. 2 ). 
     As disclosed above, transmitter  200  includes load sensing circuit  216  which detects fluctuations in the bias current provided to transmitter power amplifier  210 . Accordingly, transmitter  200  has a mechanism for determining when receivers are present in the transmitter&#39;s near-field. 
     When multiple receivers  300  are present in a transmitter&#39;s near-field, it may be desirable to time-multiplex the loading and unloading of one or more receivers to enable other receivers to more efficiently couple to the transmitter. A receiver may also be cloaked in order to eliminate coupling to other nearby receivers or to reduce loading on nearby transmitters. This “unloading” of a receiver is also known herein as a “cloaking” Furthermore, this switching between unloading and loading controlled by receiver  300  and detected by transmitter  200  provides a communication mechanism from receiver  300  to transmitter  200  as is explained more fully below. Additionally, a protocol can be associated with the switching which enables the sending of a message from receiver  300  to transmitter  200 . By way of example, a switching speed may be on the order of 100 μsec. 
     In an exemplary embodiment, communication between the transmitter and the receiver refers to a device sensing and charging control mechanism, rather than conventional two-way communication. In other words, the transmitter uses on/off keying of the transmitted signal to adjust whether energy is available in the near-filed. The receivers interpret these changes in energy as a message from the transmitter. From the receiver side, the receiver uses tuning and de-tuning of the receive antenna to adjust how much power is being accepted from the near-field. The transmitter can detect this difference in power used from the near-field and interpret these changes as a message from the receiver. 
     Receive circuitry  302  may further include signaling detector and beacon circuitry  314  used to identify received energy fluctuations, which may correspond to informational signaling from the transmitter to the receiver. Furthermore, signaling and beacon circuitry  314  may also be used to detect the transmission of a reduced RF signal energy (i.e., a beacon signal) and to rectify the reduced RF signal energy into a nominal power for awakening either un-powered or power-depleted circuits within receive circuitry  302  in order to configure receive circuitry  302  for wireless charging. 
     Receive circuitry  302  further includes processor  316  for coordinating the processes of receiver  300  described herein including the control of switching circuitry  312  described herein. Cloaking of receiver  300  may also occur upon the occurrence of other events including detection of an external wired charging source (e.g., wall/USB power) providing charging power to device  350 . Processor  316 , in addition to controlling the cloaking of the receiver, may also monitor beacon circuitry  314  to determine a beacon state and extract messages sent from the transmitter. Processor  316  may also adjust DC-to-DC converter  310  for improved performance. 
       FIG. 6  shows a simplified schematic of a portion of transmit circuitry for carrying out messaging between a transmitter and a receiver. In some exemplary embodiments of the present invention, a means for communication may be enabled between the transmitter and the receiver. In  FIG. 6  a power amplifier  210  drives the transmit antenna  204  to generate the radiated field. The power amplifier is driven by a carrier signal  220  that is oscillating at a desired frequency for the transmit antenna  204 . A transmit modulation signal  224  is used to control the output of the power amplifier  210 . 
     The transmit circuitry can send signals to receivers by using an ON/OFF keying process on the power amplifier  210 . In other words, when the transmit modulation signal  224  is asserted, the power amplifier  210  will drive the frequency of the carrier signal  220  out on the transmit antenna  204 . When the transmit modulation signal  224  is negated, the power amplifier will not drive out any frequency on the transmit antenna  204 . 
     The transmit circuitry of  FIG. 6  also includes a load sensing circuit  216  that supplies power to the power amplifier  210  and generates a receive signal  235  output. In the load sensing circuit  216  a voltage drop across resistor R s  develops between the power in signal  226  and the power supply  228  to the power amplifier  210 . Any change in the power consumed by the power amplifier  210  will cause a change in the voltage drop that will be amplified by differential amplifier  230 . When the transmit antenna is in coupled mode with a receive antenna in a receiver (not shown in  FIG. 6 ) the amount of current drawn by the power amplifier  210  will change. In other words, if no coupled mode resonance exist for the transmit antenna  204 , the power required to drive the radiated field will be a first amount. If a coupled mode resonance exists, the amount of power consumed by the power amplifier  210  will go up because much of the power is being coupled into the receive antenna. Thus, the receive signal  235  can indicate the presence of a receive antenna coupled to the transmit antenna  235  and can also detect signals sent from the receive antenna. Additionally, a change in receiver current draw will be observable in the transmitter&#39;s power amplifier current draw, and this change can be used to detect signals from the receive antennas. 
     As stated, there are other applications for wireless power in addition to charging or powering an electronic device. For example, and as will be understood by a person having ordinary skill in the art, a thermoelectric effect may be exhibited in a circuit in which metal(s) and/or semiconductor(s) having different thermoelectric properties are joined. The generation of an electric current in such a circuit when there is a difference in temperature at the junction is referred to as a Seebeck effect. Thermoelectric conversion modules which exhibit the Seebeck effect have been utilized as, for example, a power generating apparatus. Furthermore, when an electrical current flows through a circuit, the generation of heat on one side and absorption of heat on the other side of the junction occurs. This is referred to as a Peltier effect. More specifically, the Peltier effect is the heating of one junction and the cooling of an associated second junction when an electric current is maintained in junctions having two dissimilar conductors. That is, when the electric current passes through a junction of two dissimilar materials, heat is either absorbed or released depending on the direction of the electric current through the junction. Since an electric current must be closed in order to ensure a continuous current, in any closed circuit, both cooling (cold) and heating (hot) junctions exist. Thus, the presence of the electric current merely moves the heat from one place to another, and as such, a Peltier device may be used as a heat pump in heating and cooling applications. The Peltier device can also be operated in reverse, so that by maintaining a temperature difference between the hot and cold junctions an electric current can be generated. 
     Various exemplary embodiments as described herein are related to a wireless power system, wireless power receivers, and wireless power transmitters. A wireless power system may include at least one wireless power transmitter and at least one wireless power receiver. According to an exemplary embodiment, at least one wireless power transmit antenna may be positioned proximate a charging surface of a wireless power device, which may include the at least one wireless power transmitter. The at least one wireless power receiver may include at least one receive antenna, which may be positioned within a near-field region of the at least one transmit antenna of the wireless power transmitter. The at least one wireless power receiver, which may be integrated within a device, may further include a thermoelectric element (e.g., a Peltier device) configured to cool or heat at least a portion of the device in response to receipt of wireless power. Accordingly, the wireless power system may be configured to heat or cool a device (e.g., tableware or a tablemat, such as a placemat or a coaster), which is positioned proximate to or which includes the at least one wireless power receiver. 
     In accordance with one exemplary embodiment, a device to be cooled or heated (e.g., tableware) may be positioned adjacent to (e.g., positioned on) a tablemat (e.g., a coaster or a placemat) that includes the at least one wireless power receiver. Furthermore, the tablemat that includes the at least one wireless power receiver may be positioned on a charging surface of the wireless power device, which includes the at least one wireless power transmitter. As a more specific example, a wireless power device, including at least one wireless power transmitter, may be integrated within a table (e.g., a table within a restaurant) and may be configured to convey wireless power to at least one wireless power receiver having at least one receive antenna. The wireless power receiver, which may be integrated in, for example only, a coaster or a placemat, may be coupled to at least one thermoelectric element (e.g., Peltier device) configured to heat or cool at least a portion of the coaster or the placemat via a thermoelectric method (i.e., Peltier effect). Furthermore, tableware, such as, for example only, a plate, a glass, or a cup, positioned on the coaster or placemat may be heated or cooled via conduction. Additionally, contents on or within the tableware (e.g., food or beverage) may be heated or cooled via conduction. 
     Moreover, according to another exemplary embodiment of the present invention, tableware (e.g., drinkware or dishware) may include a wireless power receiver having at least one receive antenna and at least one thermoelectric element coupled thereto. As such, in this exemplary embodiment, the tableware, which may be positioned on a wireless power device (e.g., a table) having at least one transmit antenna, may be configured to wirelessly receive power. Furthermore, upon receipt of wireless power, the thermoelectric element may be configured to heat or cool at least a portion of the tableware via a thermoelectric method (i.e., Peltier effect). Additionally, contents on or within the tableware (e.g., food or beverage) may be heated or cooled via conduction. 
       FIG. 7  illustrates a charging surface  908  of a wireless power device  902  having a first device  900  and a second device  910  positioned thereon. It is noted that although first device  900  and second device  910  are each illustrated as a tableware device (i.e., a plate and a glass, respectively), first device  900  and second device  910  may each comprise any known tableware device (e.g., cup, plate, or glass) or tablemat device (e.g., a coaster or a placemat). According to one exemplary embodiment, wireless power device  902  may be configured to convey wireless power, which may be received by a receiver (not shown) within a receiver device (e.g., first device  900  or second device  910 ). Furthermore, upon receiving wireless power, first device  900  and second device  910  may each be configured to heat or cool at least a portion of itself via one or more thermoelectric methods (i.e., Peltier effect). More specifically, for example, each of first device  900  and a second device  910  may include a thermoelectric element, which may be configured to, upon receipt of wireless power, cool or heat at least a portion of the associated device via one or more thermoelectric methods known in the art. 
     Moreover, charging surface  908 , which may comprise a multi-touch display screen, may be configured to display a virtual controller  909 / 919  for each device (e.g., virtual controller  909  for first device  900  or virtual controller  919  for second device  910 ) positioned within a near-field region of wireless power device  902  and configured to heat or cool at least a portion of itself via a thermoelectric method. More specifically, virtual controller  909  associated with first device  900  may be configured to enable a device user to control a temperature of first device  900  and virtual controller  919  associated with second device  910  may be configured to enable a device user to control a temperature of second device  910 . Yet more specifically, for example, a device user may interact with virtual controller  909  via touch to adjust a temperature of first device  900  associated therewith. Similarly, a device user may interact with virtual controller  919  via touch to adjust a temperature of second device  910  associated therewith.  FIG. 10  is another depiction of first device  900  positioned on charging surface  908  with associated virtual controller displayed  909  adjacent thereto. Moreover,  FIG. 11  is another illustration of second device  910  positioned on charging surface  908  with associated virtual controller  919  displayed adjacent thereto. Temperature control associated with devices positioned within a near-field region of a wireless power device  902  will be described below in further detail. 
     In accordance with one exemplary embodiment of the present invention, wireless power device  902  may be configured to detect the presence of a device (e.g., first device  900  or second device  910 ), which includes a receiver, upon placement of the device within a near-field region of wireless power device  902 . More specifically, wireless power device  902  may be configured to detect the presence of a device (e.g., tableware or a tablemat) having a receiver integrated therein upon placement of the device on surface  908 . Wireless power device  902  may be configured to detect the presence of a device by any know and suitable means. By way of example only, wireless power device  902  may be configured to detect the presence of a device with one or more sensors (e.g., pressure or light sensors), a presence detector (e.g., presence detector  280  of  FIG. 4 ), or any combination thereof. According to another exemplary embodiment of the present invention, upon being positioned within a near-field region of wireless power device  902 , a device (e.g., first device  900  or second device  910 ) may be configured to notify wireless power device  902  of its presence by any know and suitable means. For example only, a device may notify wireless power device  902  of its presence via communication (e.g., near-field communication (NFC) means). 
     Additionally, as described more fully below, upon detection or notification of the presence of a device (e.g., first device  900  or second device  910 ), wireless power device  902  may be configured to display a virtual controller (e.g., virtual controller  909  or virtual controller  919 ). As noted above, virtual controller  909  may be configured to enable a device user to control a temperature of associated device  900 . Yet more specifically, for example, a device user may interact with virtual controller  909  via touch to adjust a temperature of associated device  900 . 
       FIG. 8  is a block diagram of a wireless power system  700 , in accordance with an exemplary embodiment of the present invention. Wireless power system  700  includes a wireless power device  702 , which may include at least one wireless power transmitter (e.g., transmitter  200  of  FIG. 4 ) including at least one transmit antenna  704 . According to one exemplary embodiment, wireless power device  702  may comprise a table (e.g., a dining table). As a more specific example, wireless power device  702  may comprise a table within a restaurant. Moreover, wireless power device  702  may include a display  710 , which may comprise, for example only, a touch sensitive screen. Display  710  may be configured to display data (e.g., images, virtual icons, text, video, etc.) on a surface  712  of wireless power device  702 . It is noted that the at least one transmit antenna  704  may be positioned approximate surface  712  and may be configured to wirelessly transmit power to one or more chargeable devices positioned within an associated near-field region (e.g., on surface  712 ). 
     Wireless power system  700  may further include one or more devices  706 , wherein each device  706  includes at least one wireless power receiver (e.g., receiver  300  of  FIG. 5 ) having at least one receive antenna  708 . In addition, each device  706  may include a thermoelectric element  714  (e.g., Peltier device) operably coupled to and configured to receive a voltage signal from at least one wireless power receiver associated with device  706 . It is noted that devices  706  may comprise, for example, first device  900  or second device  910  described above with regard to  FIG. 7 . 
     According to one exemplary embodiment, device  706  may include tableware, which may comprise, for example, dishware (e.g., a plate or a bowl) or drinkware (e.g. a glass or a cup). Accordingly, in this embodiment, upon receiving wireless power at device  706 , an associated thermoelectric element  714  may be configured to heat or cool at least a portion of associated device  706 . Therefore, contents (i.e., food or drink) within or on device  706  may be heated or cooled. More specifically, if device  706  comprises drinkware, liquid within the drinkware may be cooled or heated. Similarly, if device  706  comprises dishware, food, which is positioned on the dishware, may be heated or cooled. 
     In accordance with another exemplary embodiment, device  706  may include a tablemat (e.g., coaster or a placemat) configured for positioning tableware thereon. Therefore, in this embodiment, upon receiving wireless power at device  706 , an associated thermoelectric element  714  may be configured to heat or cool at least a portion of the associated device  706 . Moreover, tableware (e.g., a glass or a plate) positioned on device  706  may be heated or cooled according to the theory of conduction, as will be appreciated by a person having ordinary skill in the art. Furthermore, contents (i.e., food or drink) within or on the tableware may also be heated or cooled via conduction. More specifically, for example, if device  706  comprises a coaster, at least a portion of the coaster, drinkware positioned on the coaster, and liquid within the drinkware may be cooled or heated. Similarly, if device  706  comprises a placemat, at least a portion of the placemat, dishware that is positioned on the placemat, and food that is positioned on the dishware may be heated or cooled. 
     With reference to  FIGS. 7 and 8 , temperature control of devices  706  within system  700  will now be described. As noted above, display  710 , which may comprise a multi-touch screen, may be configured to display a virtual controller (e.g., virtual controller  909 ) for each device (e.g., device  706 ) positioned within a near-field region of wireless power device  702  and configured to heat or cool at least a portion of itself via one or more thermoelectric methods. More specifically, a virtual controller associated with device  706  may be configured to enable a device user to control a temperature of device  706 . According to one exemplary embodiment, device  706  may be configured to have a predetermined default temperature associated therewith. For example only, if device  706  comprises either a plate or a placemat, device  706  may be configured to have a default temperature of 150 degrees Fahrenheit. As another example, if device  706  comprises a glass, device  706  may have a default temperature of 35 degrees Fahrenheit. Accordingly, as described more fully below, device  706 , wireless power device  702 , or a combination thereof, may be configured to adjust an amount of power received by device  706  in order to keep a temperature of device  706  at an associated default temperature. It is noted that device  706  may include one or more temperature sensors and may be configured to communicate a measured temperature to wireless power device  702  via, for example, near-field communication means. 
     Furthermore, in response to a device user adjusting a temperature of device  706  via a virtual controller (e.g., virtual controller  909 ), device  706  may be configured to either increase or decrease the temperature associated therewith. More specifically, according to one exemplary embodiment, device  706 , which may also comprise a one or more temperature sensors (not shown), may be configured to measure a temperature associated therewith. Furthermore, device  706  may be configured to either increase or decrease the efficiency of wireless power transmission thereto, and, as a result, may increase or decrease the temperature of device  706 . More specifically, for example, device  706  may be configured to adjust the tuning of an associated receiver (e.g., receiver  300  of  FIG. 5 ) in order to adjust the amount of wireless power received from wireless power device  702 . Accordingly, by decreasing the amount of wireless power received from wireless power device  702 , device  706  may decrease a temperature associated therewith. Similarly, by increasing the amount of wireless power received from wireless power device  702 , device  706  may increase a temperature associated therewith. It is noted that in this exemplary embodiment, a temperature of each device  706  is independently controllable. 
     Moreover, in response to a device user adjusting a temperature of device  706  via a virtual controller (e.g., virtual controller  909 ), wireless power device  702  may be configured to either increase or decrease the temperature associated with one or more devices  706 . More specifically, according to another exemplary embodiment, wireless power device  702  may be configured to either increase or decrease the amount of power transmitted to devices  706 , and, as a result, may increase or decrease the temperature of devices  706 . It is noted that each device  706 , which, as noted above, may comprise one or more temperature sensors, may convey a temperature associated therewith to wireless power device  702  via, for example NFC means. 
       FIG. 9  is a block diagram of a wireless power system  800 , in accordance with an exemplary embodiment of the present invention. Wireless power system  800  includes a wireless power device  802 , which may include a plurality of transmitters (e.g., transmitter  200  of  FIG. 4 ), wherein each transmitter includes at least one transmit antenna  804 . As illustrated, transmit antennas  804  may be configured within wireless power device  802  in a tile pattern. It is noted, however, that although transmit antennas  804  are illustrated as being similar in size; embodiments of the present invention are not so limited. Rather, transmit antennas  804  of various sizes may be positioned within wireless power device  802  in any pattern. Similarly to wireless power device  702 , wireless power device  708  may be integrated within a table and may include a display  810 , which may comprise, for example only, a touch sensitive screen. Display  810  may be configured to display data (e.g., images, virtual icons, text, video, etc.) on a surface  812  of wireless power device  802 . It is noted that each transmit antenna  804  may be positioned approximate surface  812  and may be configured to wirelessly transmit power to one or more chargeable devices positioned within an associated near-field region (e.g., on surface  812 ). 
     Wireless power system  800  may further include one or more devices  706 , wherein each device  706  includes at least one wireless power receiver (e.g., receiver  300  of  FIG. 5 ) having at least one receive antenna  708 . In addition, each device  706  may include thermoelectric element  714  (e.g., Peltier device) operably coupled to and configured to receive a voltage signal from at least one wireless power receiver associated with device  706 . As noted above with respect to  FIG. 7 , device  706  may include tableware, such as dishware (e.g., a plate) or drinkware (e.g. a glass or a cup). Accordingly, in this embodiment, upon receiving wireless power at device  706 , an associated thermoelectric element  714  may be configured to heat or cool at least a portion of the associated device. Therefore, contents (i.e., food or drink) within or on device  706  may be heated or cooled via conduction. More specifically, if device  706  comprises drinkware, liquid within the drinkware may be cooled or heated. Similarly, if device  706  comprises dishware, food that is positioned on the dishware may be heated or cooled. 
     It is noted that, depending on a position on surface  812 , device  706  may be located within a near-field of one or more transmit antennas  804 , wherein each transmit antenna  804  is independently associated with one or more transmitters (e.g., transmitter  200  of  FIG. 4 ). Stated another way, a first device (e.g., first device  900 ; see  FIG. 7 ) may be associated with one or more receivers and a second device (e.g., second device  910 ; see  FIG. 7 ) may be associated with one or more receivers that are independent of the receivers with which the first device are associated. 
     As described above, device  706  may include a tablemat (e.g., a coaster or a placemat) configured for positioning tableware thereon. Therefore, in this embodiment, upon receiving wireless power at device  706 , an associated thermoelectric element  714  may be configured to heat or cool at least a portion of the tablemat. Moreover, tableware positioned on device  706  may be heated or cooled according to the theory of conduction, as will be appreciated by a person having ordinary skill in the art. Furthermore, contents (i.e., food or drink) within or on the tableware may also be heated or cooled via conduction. More specifically, for example, if device  706  comprises a coaster, at least a portion of the coaster, tableware (e.g., a glass) positioned on the coaster, and liquid within the tableware may be cooled or heated. Similarly, if device  706  comprises a placemat, at least a portion of the placemat, dishware that is positioned on the placemat, and food that is positioned on the dishware may be heated or cooled. 
     With reference to  FIGS. 7 and 9 , temperature control associated with devices  706  within system  800  will now be described. As noted above, display  810 , which may comprise a multi-touch screen, may be configured to display virtual controller (e.g., virtual controller  909 ) for each device (e.g., device  706 ) positioned within a near-field region of wireless power device  802  and configured to heat or cool at least a portion of an associated device via one or more thermoelectric methods. More specifically, a virtual controller associated with device  706  may be configured to enable a device user to control a temperature of device  706 . As noted above, device  706  may be configured to have a predetermined default temperature associated therewith. For example only, if device  706  comprises either a plate or a placemat, device  706  may be configured to have a default temperature of 150 degrees Fahrenheit. As another example, if device  706  comprises a glass, device  706  may have a default temperature of 35 degrees Fahrenheit. Accordingly, as described more fully below, device  706 , wireless power device  802 , or a combination thereof, may be configured to adjust an amount of power received by device  706  in order keep device  706  at an associated default temperature. It is noted that device  706  may include one or more temperature sensors and may be configured to communicate a measured temperature to wireless power device  702  via, for example, near-field communication means. 
     Furthermore, in response to a device user adjusting a temperature of device  706  via a virtual controller (e.g., virtual controller  909 ), device  706  may be configured to either increase or decrease the temperature associated therewith. More specifically, according to one exemplary embodiment, device  706 , which may also comprise a one or more temperature sensors (not shown), may be configured to measure a temperature associated therewith. Furthermore, device  706  may be configured to either increase or decrease the efficiency of wireless power transmission thereto, and, as a result, may increase or decrease the temperature of device  706 . Yet more specifically, for example, device  706  may be configured to adjust the tuning of an associated receiver (e.g., receiver  300  of  FIG. 5 ) in order to adjust the amount of wireless power received from wireless power device  702 . Accordingly, by decreasing the amount of wireless power received from one or more transmitters of wireless power device  702 , device  706  may decrease a temperature associated therewith. Similarly, by increasing the amount of wireless power received from one or more transmitters of wireless power device  702 , device  706  may increase a temperature associated therewith. 
     As stated above, a first device (e.g., first device  900 ; see  FIG. 7 ) may be associated with one or more receivers and a second device (e.g., second device  910 ; see  FIG. 7 ) may be associated with one or more receivers that are independent of the receivers with which the first device are associated. Accordingly, the first device may receive power from one or more dedicated transmitters and the second device may receive power from one or more other dedicated transmitters. Moreover, in response to a device user adjusting a temperature of device  706  via a virtual controller (e.g., virtual controller  909 ), wireless power device  702  may be configured to either increase or decrease the temperature associated with one or more devices  706 . More specifically, according to another exemplary embodiment, one or more transmitters associated with device  706  may either increase or decrease the amount of power transmitted to device  706 , and, as a result, may increase or decrease the temperature of device  706 . It is noted that device  706 , which, as noted above, may comprise one or more temperature sensors, may convey a temperature associated therewith to the one or more associated transmitters via, for example, NFC means. 
       FIG. 12  is a flowchart illustrating a method  980 , in accordance with one or more exemplary embodiments. Method  980  may include receiving wireless power at a device (depicted by numeral  982 ). Method  980  may further include thermoelectrically heating or cooling at least a portion of the device upon receipt of the wireless power (depicted by numeral  984 ). 
       FIG. 13  is a flowchart illustrating a method  990 , in accordance with one or more exemplary embodiments. Method  990  may include transmitting wireless power to at least one device (depicted by numeral  992 ). Method  990  may further include displaying a virtual controller adjacent the device and configured to enable a device user to adjust a temperature of at least a portion of the device (depicted by numeral  994 ). 
     Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the exemplary embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the exemplary embodiments of the invention. 
     The various illustrative logical blocks, modules, and circuits described in connection with the exemplary embodiments disclosed herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. 
     The steps of a method or algorithm described in connection with the exemplary embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. 
     In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. 
     The previous description of the disclosed exemplary embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these exemplary embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the exemplary embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.