Patent Publication Number: US-11655161-B2

Title: Modular water purification device

Description:
CLAIM OF BENEFIT TO PRIOR APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 16/945,768, filed on Jul. 31, 2020, and published as U.S. Patent Publication No. 2021/0039007. U.S. patent application Ser. No. 16/945,768 claims the benefit of U.S. Provisional Patent Application Ser. No. 62/883,076, filed on Aug. 5, 2019. The contents of U.S. patent application Ser. No. 16/945,768 published as U.S. Patent Publication No. 2021/0039007 and U.S. Provisional Patent Application 62/883,076 are hereby incorporated by reference. 
    
    
     BACKGROUND 
     Population growth and industrial advances have resulted in increased fresh water demand for domestic, farming, and industrial uses. As demand for freshwater increases, traditional sources of freshwater such as reservoirs, wells, rivers, and lakes are becoming depleted. 
     The vast amount of salt water in the oceans, brackish water in estuaries and aquifers, brine in the Earth&#39;s surface and crust, and water in rivers and lakes may be purified for use as fresh water for different applications. Different purification and desalination techniques are used to produce purified water. These techniques are generally expensive to implement, require large amount of energy, and the resulting purification and desalination plants are not modular and scalable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various embodiments of the present modular water purification device now will be discussed in detail with an emphasis on highlighting the advantageous features. These embodiments depict the novel and non-obvious modular water purification device shown in the accompanying drawings, which are for illustrative purposes only. These drawings include the following figures, in which like numerals indicate like parts: 
         FIG.  1 A  is a front elevational view of one example embodiment of a modular water purification device where the purified water may be cascaded through several modular water purification devices, according to various aspects of the present disclosure; 
         FIG.  1 B  is a front elevational view of one example embodiment of a modular water purification device where the purified water is transferred out of each modular water purification device, according to various aspects of the present disclosure; 
         FIG.  2    is a front elevational view of one example embodiment of a cascade of modular water purification devices where the purified water may be cascaded through several modular water purification devices, according to various aspects of the present disclosure; 
         FIG.  3    is a front elevational view of one example embodiment of a cascade of modular water purification devices where the purified water is transferred out of each modular water purification device, according to various aspects of the present disclosure; 
         FIG.  4    is an upper front perspective view of a Peltier device, according to various aspects of the present disclosure; 
         FIG.  5 A  is a top elevational view of the modular water purification device of  FIG.  1 A , according to various aspects of the present disclosure; 
         FIG.  5 B  is a top elevational view of the modular water purification device of  FIG.  1 B , according to various aspects of the present disclosure; 
         FIG.  6 A  is an upper front perspective view of one example embodiment of a modular water purification device, according to various aspects of the present disclosure; 
         FIG.  6 B  is an upper rear perspective view of the modular water purification device of  FIG.  6 A , according to various aspects of the present disclosure; 
         FIG.  6 C  is an upper front perspective view of one example embodiment of a modular water purification device that includes one or more solar panels, according to various aspects of the present disclosure; 
         FIG.  6 D  is an upper rear perspective view of the modular water purification device of  FIG.  6 C , according to various aspects of the present disclosure; 
         FIGS.  6 E and  6 F  are side elevational views of one example embodiment of a modular water purification device that includes one or more foldable solar panels, according to various aspects of the present disclosure; 
         FIG.  7    is a state diagram for a modular water purification device, according to various aspects of the present disclosure; 
         FIG.  8    is a functional block diagram of one example embodiment of a cascade of modular water purification devices that includes one or more rows of modular water purification devices, according to various aspects of the present disclosure; 
         FIGS.  9 A- 9 B  are a flowchart illustrating an example process for purifying water by a cascade of modular water purification devices, according to various aspects of the present disclosure. 
         FIGS.  10 A and  10 B  are a flowchart illustrating an example process for purifying water by a cascade of modular water purification devices, according to various aspects of the present disclosure; 
         FIG.  11    is a functional block diagram of one example embodiment of a cascade of modular water purification devices with one or more control and monitoring servers and a robot for replacing Peltier devices, according to various aspects of the present disclosure; 
         FIG.  12    is a front elevational view of one example embodiment of a cascade of modular water purification devices that receives electricity from solar panels associated with one or more of the modular water purification devices, according to various aspects of the present disclosure; 
         FIG.  13    is a front elevational view of one example embodiment of a cascade of modular water purification devices that receives electricity from one or more solar panels, according to various aspects of the present disclosure; 
         FIG.  14    is a front elevational view of one example embodiment of a cascade of modular water purification devices and different sources of energy that may be used by the cascade, according to various aspects of the present disclosure; 
         FIG.  15    is a front elevational view of one example embodiment of a cascade of modular water purification devices that receives energy from a utility power line, according to various aspects of the present disclosure; 
         FIG.  16    is a front elevational view of one example embodiment a single modular water purification device used as a standalone water purification device, according to various aspects of the present disclosure; 
         FIG.  17 A- 17 C  illustrate examples of curves illustrating the rate of increase of temperature during a water purification cycle, according to various aspects of the present disclosure; and 
         FIG.  18    is a functional block diagram of one example embodiment of an electronic system with which some embodiments of the invention are implemented. 
     
    
    
     DETAILED DESCRIPTION 
     One aspect of the present embodiments includes the realization that purifying a large amount of water for municipal, farming, or industrial use requires large plants that are expensive and consume large amount of electricity. Such plants are time consuming to construct and are difficult to repair. The plants that vaporize feed water and condensate the water vapor into purified water need compressors and refrigerants. The compressors have moving parts that may break down. The refrigerants may pollute the environment and may contribute to the greenhouse gas effect. 
     Some of the present embodiments solve the aforementioned problems by providing a modular water purification device and may be connected to similar devices to form a cascade of water purification devices. Cascading the modular water purification devices provides scalability by adding or removing individual devices. The modular devices may provide health status and performance metrics. Faulty devices may quickly be identified and replaced. 
     Each modular water purification device may have a valve for taking in feed water (e.g., salt water, brackish water, brine, water from lakes, rivers, wells). The cascade may go repeatedly through a fill cycle, followed by a water purification cycle, followed by a wash cycle. During the fill cycle, the feed water reservoir in each modular device is filled with feed water. During the water purification cycle, the feed water is vaporized and condensed into purified water. During the wash cycle the feed water is passed through each modular device in order to wash the salt and/or other sediments that may be accumulated inside the modular devices. The purified water, in some embodiments, may be transferred through the cascade and collected into a reservoir. The purified water, in other embodiments, may be transferred out of each individual modular device into one or more reservoirs. 
     Some of the present embodiments use a Peltier device to heat the feed water into water vapor and to condense the water vapor into purified water. The Peltier device creates a cooling effect without a compressor, refrigerants, or moving parts. The Peltier devices are durable, consume small amount of energy, easy to diagnose, and easy to replace. 
     Some of the present embodiments may provide assistance to the Peltier device to heat the water. Some of these embodiments may use heat directly received from the Sun to heat the feed water and/or to generate water vapor. Some of the present embodiments use electricity generated from solar cells to heat the feed water and/or to generate water vapor. Some of these embodiments may receive enough energy directly from the sun and/or from solar panels that the water purification cascade may work as a standalone system without needing external sources of energy, for example, from a municipal power grid. Some embodiments may provide one or more auxiliary heating elements that may be turned on if the heat generated by the Peltier device is either not enough to boil water or the Peltier device may take longer than a time limit to heat the water. Some embodiments may provide a fan inside the modular water purification device to move the hot water vapor down from a hot water vapor chamber towards a condensation chamber. 
       FIG.  1 A  is a front elevational view of one example embodiment of a modular water purification device where the purified water may be cascaded through several modular water purification devices, according to various aspects of the present disclosure. The modular water purification device  100  (also referred to as modular desalination device when the device is used for desalinating salt water, brackish water, or brine water) may be used as a portable device or may be anchored, for example, to a platform. The modular water purification device  100  may be connected to several other modular water purification devices to form a cascade for purifying water. 
     With reference to  FIG.  1 A , the modular water purification device  100  may include a frame  105 , several valves  101 - 104 , a hot water vapor chamber  110 , a condensation chamber  115 , a water vapor channel  116 , a feed water reservoir  120 , one or more water level sensors  121 , one or more humidity sensors  122 , one or more temperature sensors  123 , a cascade power feed  130 , a cascade signal feed  136 , several pipes (or channels)  131 - 134 , a thermoelectric cooler (or Peltier device)  140 , a controller  150 , one or more auxiliary heating elements  155 , one or more support structures (e.g., beams, poles, columns, etc.)  171 - 172 , a fan  180 , insulators  185 , a local power feed  190 , and a local signal feed  195 . 
     The frame  105  may encompass the hot water vapor chamber  110 , the condensation chamber  115 , the water vapor channel  116 , the feed water reservoir  120 , and the Peltier device  140 . The valve  101  may bring feed water (also referred herein as pre-purified water) through the feed water input pipe (or channel)  131 . Examples of the feed water include, without any limitations, salt water from the oceans, salt water from lakes, brackish water from estuaries and aquifers, brine from the Earth&#39;s surface and crust, fresh water from rivers, lakes, well, tap water that may require purification, etc. When the modular water purification device  100  is the first device in the cascade, the feed water may come from an outside water source. When the modular water purification device  100  is not the first device in the cascade, the feed water may come from the previous device in the cascade. 
     The feed water may be stored in the feed water reservoir  120 . The feed water reservoir  120  may be made of a non-corrosive material such as, for example, and without limitations, galvanized steel, aluminum, etc. The feed water reservoir  120 , in some embodiments, may be in the shape of an open bowl, which may be secured to the sides of the frame  105  and the support structure(s)  171  such that no feed water may leak into the condensation chamber  115 . 
     In some of the present embodiments, a thin metal plate (not shown), made of a non-corrosive material such as, for example, and without limitations, galvanized steel, aluminum, etc., may cover the hot side  143  of the Peltier device  140 , may function as the bottom of the feed water reservoir  120 , and may seal the water reservoir  120  such that no feed water may leak into the condensation chamber  115 . The valve  102  may transfer the feed water out of the modular water purification device  100  trough the feed water output channel  132 . 
     In some of the present embodiments (such as the embodiment depicted in  FIG.  1 A ), the purified water may be channeled through the cascade by the valves  103  and  104  through purified water pipes  133  and  134 . In other embodiments (such as the embodiment shown in  FIG.  1 B ), the purified water may be transferred out of each modular water purification device  100  into one or more external purified water reservoirs. The feed and purified water channels may be made of material such as, without limitations, polyvinyl chloride (PCV), Chlorinated polyvinyl chloride (CPVC), copper, galvanized steel, galvanized iron, chromed copper, etc. 
       FIG.  1 B  is a front elevational view of one example embodiment of a modular water purification device where the purified water is transferred out of each modular water purification device, according to various aspects of the present disclosure. With reference to  FIG.  1 B , the purified water that is collected at the bottom of the frame  105  may be transferred out of the modular water purification device  100  through a valve  106  and the purified water output channel  135 . Other components of  FIG.  1 B  may be similar to the corresponding components of  FIG.  1 A . 
     Some embodiments may include a mineral mixer on the purified water output  135  to add minerals to the purified water. In the embodiments that the purified water output  134  ( FIG.  1 A ) is carried through the cascade, the mineral mixer (not shown) may be placed on the purified water output  134  of the last modular water purification device  100  in the cascade. Further details of the mineral mixers of the present embodiments are provided below with reference to the mineral mixer  1605  of  FIG.  16   . 
     Some embodiments may measure the level  125  and/or the flow of the purified water over time, which may be used in identifying the efficiency of the system and determining the amount of the purified water generated by the system. Some embodiments may include a flow meter  127  ( FIG.  1 B ) at the purified water output  135  of each modular water purification device  100  to measure the flow of the purified water. In the embodiments that the purified water output  134  ( FIG.  1 A ) is carried through the cascade, the flow meter (not shown) may be placed on the purified water output channel  134  of the last modular water purification device  100  in the cascade. The flow meter  127 , in some embodiments, may be integrated inside the purified output valve  106  ( FIG.  1 B ) of each modular water purification device  100 . In some of the embodiments that the purified water output  134  ( FIG.  1 A ) is carried through the cascade, the flow meter may be integrated in the purified output valve  104  of the last modular water purification device  100  in the cascade. 
     In addition to, or in lieu of the flow meter, some embodiments may use one or more sensors inside a modular water purification device  100  to measure the level  125  of the purified water at different time instances. For example, some embodiments may include an array of light detectors (not shown) on the of inside of one of walls of the modular water purification device  100  and an array of light emitting didoes (LEDs) (not shown) or any other light source on an opposite wall of the modular water purification device  100 . 
     The array of light detectors and the array of LEDs may be positioned towards the bottom of the modular water purification device  100  where the purified water is collected. The part of the array of the light detectors that is below the purified water level  125  may detect a different light pattern than the part that is outside the purified water and the boundary between the two parts may be detected to provide an indication of the purified water level  125 . 
     As described further below with reference to  FIG.  3   , the purified water may be transferred from the purified water output channel  135  of  FIG.  1 B  into one or more external reservoirs. Although only one valve  106  and one purified water output channel  135  are shown in  FIG.  1 B , the modular water purification device  100 , in some embodiments, may have several purified water output channels and the corresponding valves for transferring the purified water out of the device. In addition, since the purified water in the embodiments of  FIG.  1 B  is not channeled through the cascade, different modular water purification devices (e.g., different models) may have different number of purified water output channels. 
       FIG.  2    is a front elevational view of one example embodiment of a cascade  200  of modular water purification devices where the purified water may be cascaded through several modular water purification devices, according to various aspects of the present disclosure. The modular water purification devices  100  of  FIG.  2    may be similar to the modular water purification device  100  of  FIG.  1 A . For simplicity,  FIG.  2    only shows the interconnection of input and output channels of the feed water and the purified water of the modular water purification devices  100  in the cascade  200 . 
     With reference to  FIG.  2   , the valve  101  may bring the feed water into the modular water purification device  100 . The valve  102  may transfer the feed water out of the modular water purification device  100 . The feed water output channel  132  of each device (except the last device in the cascade  200 ) may be connected to the feed water input channel  131  of next device in the cascade  200 , for example and without limitation, through a pipe fitting  215 . When the modular water purification device  100  is the last device in the cascade  200 , the feed water may be transferred outside the cascade  200 . 
     The valve  103  may bring purified water into the modular water purification device  100  through the purified water input pipe (or channel)  133 . The valve  104  may transfer purified water out of the modular water purification device  100  through the purified water output pipe (or channel)  134 . The purified water output channel  134  of each device (except the last device in the cascade  200 ) may be connected to the purified water input channel  133  of next device in the cascade  200 , for example and without limitation, through a pipe fitting  210 . When the modular water purification device  100  is the first device in the cascade  200 , the valve  103  may be closed and no purified water may come from into the device. When the modular water purification device  100  is not the first device in the cascade  200 , the purified water may come from the previous device in the cascade. 
       FIG.  3    is a front elevational view of one example embodiment of a cascade  300  of modular water purification devices where the purified water is transferred out of each modular water purification device, according to various aspects of the present disclosure. The valves  101 - 102  in  FIG.  3    may be similar to the valves  101 - 102  in  FIG.  2   , and the feed water channels  131  and  132  in  FIG.  3    may be connected to each other, as described above with reference to  FIG.  2   . 
     With reference to  FIG.  3   , the purified water is transferred out of each modular water purification device  100  into one or more external reservoirs  310  (only one reservoir is shown). Each modular water purification device  100  may be supported by one or more support structures  350 . The support structures may be, without limitation, in the form of poles, tubes, columns, etc., such that the movement of purified water inside the purified water reservoir(s) is not blocked. 
     Each modular water purification device  100  may include one or more valves  106  and the corresponding purified water output channel(s)  135  (e.g., one or more pipes) for transferring the purified water out of the modular water purification device  100 . The cascade  300  may include one or more sensors  305  for measuring the level  320  of the purified water inside the purified water reservoir(s)  310 . 
     With reference to  FIGS.  1 A- 1 B , the valves  101 - 104  and  106  may be electronically controllable. In some of the present embodiments, the valves  101 - 104  and  106  may receive control signals through the local control signal feed  195  to open or close. For example, the valves  101 - 104  and  106  may receive the signals from the controller  150  (or from a controller outside the modular water purification device  100 ). 
     The controller  150  may be (or may include) a processing unit. Examples of the processing unit may include, for example, and without limitations, as a processor such as a microprocessor, a controller, a microcontroller, a central processing unit or CPU, etc. The controller  150  may include (or may be associated with) volatile memory and non-volatile storage. The controller may receive, for example, from one or more flow meters (not shown) and/or may calculate the amount of the feed water that comes into the modular water purification device  100 , the amount of the feed water that is transferred out, the amount of the purified water that comes in (in case of  FIG.  1 A ), and/or the amount of the feed water that is transferred out using the characteristics of the valves  101 - 104  and  106  and the amount of time each valve is kept opened. Although the controller  150  is shown to be located inside the frame  105  of the modular water purification device  100 , in some embodiments, the controller  150  may be located outside the frame  105 . 
     The controller may receive and/or calculate other metrics such as, for example, and without limitations, humidity, temperature, feed and/or purified water level(s), pressure, etc., from different sensors of the modular water purification device  100 . 
     As described below, the modular water purification device  100  may go through several cycles during its operation and the valves  101 - 104  may receive signals to open and close during different cycles. Although only one valve is shown for each function of bringing in the feed water, bringing in the purified water, transferring the feed water out, and transferring the purified water out, some of the present embodiments may use more than one valve and the associated channels for some of these functions. 
     With further reference to  FIGS.  1 A- 1 B , the modular water purification device  100  may include a Peltier device  140 . The Peltier device is a thermoelectric cooling device that uses Peltier effect to create a heat flux at the junction of two different material.  FIG.  4    is an upper front perspective view of a Peltier device, according to various aspects of the present disclosure. 
     With reference to  FIG.  4   , the Peltier device  140  may include a cold side  142 , a hot side  143 , several electrical conductors  420 , several p-type semiconductors  440 , and several n-type semiconductors  445 . The p-type semiconductor may be, for example, p-doped bismuth telluride. The n-type semiconductor may be, for example, n-doped bismuth telluride. 
     The semiconductors  440 - 445  are placed thermally in parallel to each and electrically in series. A p-type semiconductor and an n-type semiconductor are placed next to each other as a semiconductor couple. A Peltier device may include from one to hundreds of semiconductor couples. The semiconductors  440 - 445  are joined with the thermally conductive plates  142  and  143 , which are referred to as the cold side and the hot side, respectively. The cold side  142  and the hot side  143  plates may be made of a material such as, for example, ceramic to act as a heat conductor and an electrical insulator. 
     When a voltage is applied, for example from a power source  430 , such as the local power feed  190  ( FIGS.  1 A- 1 B ), to the electrical conductors  120 , a flow of direct current is generated in series across the junction of the semiconductors, causing a temperature difference. The side with the cooling plate  142  absorbs heat, the heat is then moved to the hot side  143  of the Peltier device  140 . The Peltier device  140  creates a cooling effect without a compressor, refrigerants, or moving parts. 
     For the Peltier device  140  to operate properly and efficiently, the heat generated on the hot side  143  must be removed and transferred from the Peltier device  140 . In applications such as cooling of processor chips in high performance computers, this heat removal is accomplished via heat sinks placed on the hot side of the device. In the embodiments of the present invention, the water on the hot side  143  of the Peltier device  140  acts as the heat sink and the heat generated on the hot side  143  helps with generating the needed water vapor. The embodiments of the present invention are ideal applications where both the cold  142  and hot  143  sides of the Peltier device  140  are efficiently used to accomplish the water purification task. In contrast, in applications such as cooling of processor chips, extra work must be done to move the heat from the hot side of the Peltier device. 
     With reference to  FIGS.  1 A and  1 B , the Peltier device  140  may receive power (i.e., electrical power or electricity) from the local power feed  190 . The Peltier device&#39;s hot side  143  may heat up and evaporate the feed water stored in the feed water reservoir  120 . Some of the present embodiments may include one or more auxiliary heating elements  155 . The heating element(s)  155  may receive power from the local power feed  190  and may generate heat in addition to the heat generated by the Peltier device&#39;s hot side  143  in order to evaporate the feed water. 
     The auxiliary heating elements  155 , in some embodiments, may be turned on or off by the controller  150 . For example, the controller  150  may receive temperature measurements from one or more temperature sensors  123  inside the feed water reservoir  120  to measure the temperature of the feed water. The controller  150  may receive temperature measurements from one or more temperature sensors  123  inside the hot water vapor chamber  110  to measure the temperature of the gas (e.g., air or water vapor) inside the hot water vapor chamber  110 . 
     The controller  150  may determine the rate of change of temperature inside the feed water reservoir  120  during the water purification cycle. The controller  150  may determine the amount of water in the feed water reservoir from the feed water level sensor(s)  121  measurements. The controller  150  may use a function of the rate of change of temperature inside the feed water reservoir  120 , the amount of water that is in the feed water reservoir  120 , the time elapsed since the start of the water purification cycle, and/or the temperature outside of the frame  105  in order to determine whether to turn the auxiliary heating element(s)  155  on or off. For example, the controller  150  may turn on the auxiliary heating element(s)  155  if the controller  150  determines that the rate of change of the temperature of water inside the feed water reservoir  120  is not high enough for the water to reach the boiling point. As another example, the controller  150  may turn on the auxiliary heating element(s)  155  if the controller  150  determines that it may take a long time into the water purification cycle before the water in the feed water reservoir  120  comes to a boiling point and it may be more efficient to turn the auxiliary heating element(s)  155  to reach the boing point faster. 
     The controller  150  may turn off the auxiliary heating element(s)  155  if, for example, the controller  150  determines that the water in the feed water reservoir has reached the boiling point. In some embodiments, the controller  150  may keep the auxiliary heating element(s)  155  on for a time period after the water reaches the boiling point before turning off the auxiliary heating element(s)  155 . 
       FIG.  17 A- 17 C  illustrate examples of curves illustrating the rate of increase of temperature during a water purification cycle, according to various aspects of the present disclosure. The curves  1701 - 1703  show the temperature measurements inside the feed water reservoir that are made during a water purification cycle (the normalized time for the water purification cycle is shown starting from 0 and ending to t PC ). The boiling temperature of water in the feed water reservoir  120  is shown at TMP B . 
     In the example of  FIG.  17 A , the controller  150  may receive the temperature measurements and may determine that the slope of the curve  1701  is rising. For example, after receiving a plurality of temperature measurements at the beginning of the water purification cycle (e.g., during the period  1730 ), the controller  150  ( FIGS.  1 A- 1 B ) may determine that the temperature of water inside the feed water reservoir may rise and may eventually reach the boiling temperature of water TMP B  at time t 1 . If the controller  150  determines that reaching the boiling temperature of water at time t 1  provides enough remaining time during the water purification cycle to vaporize at least a predetermined amount of water, the controller  150  may not turn on the auxiliary heating element(s)  155  ( FIGS.  1 A- 1 B ). 
     In the example of  FIG.  17 B , the controller  150  may receive the temperature measurements during the period  1730  and may determine that the slope of the curve  1702  is not rising enough to reach the boiling temperature TMP B  during the water purification cycle (e.g., as shown by the curve  1740  that may be determined by the controller  150  by extrapolating the temperature measurements during the period  1730 ). The controller  150  may turn on the auxiliary heating element(s)  155  at time t 1 . In some embodiments, after the temperature of water inside the feed water reservoir reaches the boiling temperature TMP B , the controller  150  may turn off the auxiliary heating element(s)  155  (e.g., at time t 3 ). In other embodiments, the controller  150  may not turn off the auxiliary heating element(s)  155  until the end of the water purification cycle. 
     In the example of  FIG.  17 C , the controller  150  may receive the temperature measurements during the period  1730  and may determine that the slope of the curve  1703  is such that the temperature inside the feed water reservoir may reach the boiling temperature TMP B  at time t 4  (e.g., as shown by the curve  1740  that may be determined by the controller  150  by extrapolating the temperature measurements during the period  1730 ). If the controller  150  determines that reaching the boiling temperature of water at time t 4  may not provide enough remaining time during the water purification cycle to vaporize at least a predetermined amount of water, the controller  150  may turn on the auxiliary heating element(s)  155  (e.g., at time t 5 ). The embodiment of  FIG.  17 C  provides the technical advantage of purifying at least a per-determined amount of water during a water purification cycle. The controller  150  may, therefore, control the turning on or off of the auxiliary heating element(s)  155  in order to purify a certain volume of water in the cycle. 
     In some embodiments, after the temperature of water inside the feed water reservoir reaches the boiling temperature TMP B , the controller  150  may turn off the auxiliary heating element(s)  155  (e.g., at time t 6 ). In other embodiments, the controller  150  may not turn off the auxiliary heating element(s)  155  until the end of the water purification cycle. 
     It should be noted that the characteristics of the curves  1701 - 1703  may depend on the initial temperature of the feed water at the beginning of the water purification cycle, the amount of feed water collected inside the feed water reservoir at the beginning of the water purification cycle, etc. 
     In addition, the time of the day and whether there is sunlight may affect the curves  1701 - 1703 . As described below with reference to  FIGS.  6 A- 6 F , a portion of the frame  105 , in some embodiments, may include glass and/or may generate a lens effect that may transfer heat from the sun into the top portion of the modular water purification device  100  to heat the feed water and/or to generate water vapor. Other embodiments may only use the Peltier device&#39;s hot side  143  to evaporate the feed water. 
     The Peltier device  140  may be able to create a temperature difference between the hot side  143  and the cold side  142 . Depending on the ambient temperature, the temperature of the hot side  143  may reach to a temperature that may boil the feed water. Some of the present embodiments may measure the temperature of the different parts of the modular water purification device  100  (e.g., the temperature of the feed water in the feed water reservoir  120  and/or the temperature of the hot water vapor chamber  110  using one or more temperature sensors  123 ). In some of these embodiments, the auxiliary heating element(s)  155  may be turned on during the water purification cycle if the temperature of the hot side  143  of the Peltier device  140  is not enough to boil the per-purified water. The auxiliary heating element(s)  155  may be made of metal and may generate heat when electricity is passed through them. The auxiliary heating element(s)  155 , in some embodiments, may be inside the feed water reservoir  120  and may be fixed to the feed water reservoir  120  at one or more places. 
     The Peltier device  140  may be substantially as wide as the feed water reservoir  120 . The Peltier device  140 , the auxiliary heating element(s)  155 , and the feed water reservoir  120  may be supported on three sides by the frame  105  and on one side by the support structure(s)  171 . The support structure(s)  171  may be a column, a beam, a pole, or otherwise a structure that does not block the movement of water vapor from the hot water vapor chamber  100  into the water vapor channel  116 . As described below with reference to  FIG.  11   , the Peltier device, in some embodiments, may be on a set of rails on at least two sides to allow easy removal and replacement of the Peltier device  140 . 
     With reference to  FIGS.  1 A- 1 B , as the feed water is heated by the Peltier device&#39;s hot side  143  (and optionally by other means such as the auxiliary heating element(s)  155  and/or the heat received from the Sun), the hot water vapor rises into the hot water vapor chamber  110 . The hot water vapor may move from the hot water vapor chamber  110  into the water vapor channel  116  by convection. Some of the present embodiments may include a fan  180  in the water vapor channel  16  between the hot water vapor chamber  110  and the condensation chamber  5  to move the water vapor from the upper portion of the water vapor channel  116  to the lower portion of the water vapor channel  116  and to the condensation chamber  115 . 
     The fan  180 , in some embodiments, may operate at a rate per minutes (RPM) that does not create turbulence in the water vapor channel  116 . For example, the fan&#39;s RPM may be 1, 2, 5, 10, 20, etc. The fan  180  may be placed on a support structure, such as, for example, and without limitations, the support structure  172 . The support structure  172  may be a column, a beam, a pole, or otherwise a structure that does not block the movement of water vapor from the upper portion of the water vapor channel  116  into the lower portion of the water vapor channel  116 . Since the hot gasses tend to rise, the fan  180  provides the technical advantage of moving the hot air from the hot water vapor chamber  110  (which is located on the upper portion of the frame  105 ) down into the condensation chamber  115  (which is located on the lower portion of the frame  105 ). The speed of the fan  180  and its on-off timing, in some embodiments, may be controlled by the controller  150 . The controller  150  may change the speed of the fan  180  to change the amount of hot water vapor that may move from the hot water vapor chamber  110 , through the water vapor channel, and into the condensation chamber  115 . 
     For example, the fan  150  may be off at the beginning of a water purification cycle. The controller  150  may receive temperature measurements from one or more temperature sensors  123  inside the feed water reservoir  120 . The controller  150  may keep the fan  150  off until the temperature measurements indicate that the feed water is boiling inside the feed water reservoir  120 . The controller  150  may receive the measurement of the amount of water that is purified (e.g., and without limitations, from the flow meter  127 ) after the feed water starts boiling during a purification cycle. The controller  150  may start the fan  180  (e.g., by applying power to the fan) if the amount of water that is purified during the purification cycle is below a threshold. The controller  150  may continue receiving the measurement of the amount of water that is purified after the fan is started and may increase the speed of the fan  180  if the amount of water that is purified during the purification cycle is below the threshold. The controller  150  may turn off the fan (e.g., by removing power from the fan) either at the end of the water purification cycle or when the amount of purified water during the water purification cycle reaches the threshold. 
     It should be noted that the fan  180  is completely located inside the frame  105  of the modular water purification device  100  and moves the air and vapor inside the frame  105  in a closed chamber. The fan  180  is unlike a fan that has access to outside air and may circulate air and gasses between inside and outside of a chamber (e.g., to cool the chamber). Due to the fact that, unlike in conventional applications, the fan  180  of the present embodiments is used in a closed environment with the sole function of moving the hot water vapor from one chamber to another, being able to control its speed and its on-off timing is essential in order to avoid creating turbulence inside the chambers. 
     Some of the present embodiments may not use a fan and may allow the water vapor to move from the hot water vapor chamber  110  into the water vapor channel  116  and the condensation chamber  115  by convection. The water vapor in the condensation chamber  115  may come into contact with the Peltier device&#39;s cold side  142  and may condense into purified water. The purified water may be collected at the bottom of the frame  105 . 
       FIG.  5 A  is a top elevational view of the modular water purification device of  FIG.  1 A , according to various aspects of the present disclosure. With reference to  FIG.  5 A , the Peltier device, the feed water reservoir, the hot water vapor chamber, and the condensation chamber may substantially extend on three sides to the three sides  501 - 503  of the frame  105  and on one side (as shown by  504 ) to the interior of the frame  105 . The Peltier device and the feed water reservoir may be supported by the support structure(s)  171 . The support structures may be one or more beams, bars, poles, etc., for holding the Peltier device and the feed water reservoir. 
     With further reference to  FIG.  5 A , the auxiliary heating element(s)  155  may have any arbitrary shape. The auxiliary heating element(s)  155  may be connected to the frame  105  by one or more structures  590  such as rods, beams, poles, etc. 
       FIG.  5 B  is a top elevational view of the modular water purification device of  FIG.  1 B , according to various aspects of the present disclosure. With reference to  FIG.  5 B , the modular water purification device  100  may include a purified water output channel  135  and a valve  106  that may transfer the purified water to a reservoir outside the modular water purification device  100 . Other components of  FIG.  5 B  may be similar to the components of  FIG.  5 A . 
     With reference to  FIGS.  5 A- 5 B , the relative location of the feed water input channel  131 , the feed water output channel  132 , the purified water input channel  133 , the purified water output channel  134 - 135 , the cascade power feed  130 , the cascade signal feed  136 , the support structures  171 - 172 , the fan  180 , the controller  150 , and the valves  101 - 105  are shown as example. The location of these components may change in different embodiments as a design choice. 
     With reference to  FIGS.  1 A- 1 B , the frame  105  may be used to cover the water purification device&#39;s components.  FIG.  6 A  is an upper front perspective view of one example embodiment of a modular water purification device, according to various aspects of the present disclosure.  FIG.  6 B  is an upper rear perspective view of the modular water purification device of  FIG.  6 A , according to various aspects of the present disclosure. 
     With reference to  FIGS.  6 A and  6 B , the modular water purification device  150  may include a cascade signal feed  136 . In some of the present embodiments, the controller  150  ( FIGS.  1 A- 1 B ) may collect health and status information from different components of the modular water purification device. The controller  150  may calculate performance metrics such as the amount of purified water generated in a time period, the input and output rate of the feed water, etc. The controller  150  may receive data regarding temperature, pressure, humidity, flow rate, water level, etc., from different sensors of the modular water purification device  100 . The controller  150  may filter the data, calculate different metrics, and/or store raw and calculated metrics. As described below with reference to  FIG.  11   , the controller may communicate the information with one or more electronic devices through the cascade signal feed  136 . 
     The cascade signal feed  136  may go through the modular water purification devices by connecting the cascade signal feeds  136  of the adjacent devices. The cascade signal feed wire(s)  136  wires may go through a tube  640  that may be accessible through a fixture  685  that is attached to the frame  105  by one or more bolts or screws  686 . The cascade signal feed  136  may be one or more wires. Some embodiments may include one or more antennas (not shown) that may be used by the controller, in addition to, or in lieu of, the cascade signal feed, to communicate with one or more electronic devices. 
     With continued reference to  FIGS.  6 A and  15 B , the modular water purification device  150  may include a cascade power feed  130 . The cascade power feed  130  may be two or more wires that may go through a tube  645  that may be accessible through a fixture  660  that is attached to the frame  105  by one or more bolts or screws  661 . 
     In some of the present embodiments, the top portion (e.g., the portion above the line  670 ) of the frame  105  that covers the hot water vapor chamber  110  ( FIGS.  1 A- 1 B ) and the feed water reservoir  120  may be made of a transparent material such as glass that allow the sunlight to enter the top portion  670  of the frame  105  to heat up the feed water and/or generate hot water vapor. The extra energy received from the Sun through the transparent portion of the frame may be used in addition to the energy received from the Peltier device and/or the auxiliary heating element(s)  155  ( FIGS.  1 A- 1 B ). The transparent material, in some embodiments, may be made to create a lens effect to further intensify the sunlight entering the top portion  670  of the frame  105 . 
     With further reference to  FIGS.  6 A and  6 B , the lower portion (e.g., the portion below the line  670 ) of the frame  105  that covers the condensation chamber  115  ( FIGS.  1 A- 1 B ) may be made of opaque material to block the sunlight. The lower portion of the frame  105 , in some embodiments, may be covered by an insulator and/or may be made of insulating material to thermally insulate the lower portion of the frame  105 . The lower portion of the frame  105 , in some embodiments, may be double layered with vacuum between the two layers to provide insulation. 
     With further reference to  FIGS.  6 A and  6 B , a portion the frame  105  (e.g., the portion between the lines  670  and  675 ) may be covered by an insulator  185 . In the depicted embodiment, the insulator covers the area of the frame  105  that is in contact with the Peltier device  140  ( FIGS.  1 A- 1 B ) to prevent heat exchange between the Peltier device and the outside of the modular water purification device  100 . 
     In some of the present embodiments, a portion of the frame  105  that is connected to the Peltier device (e.g., the portion on the side  503  that is directly under the insulator  185 ) may be removable. The removable portion of the frame may be connected to a gripping element  605  such as a handle, a hook, a bar, a magnet, etc., that may allow the easy removal and insertion of the Peltier device into the frame  105 . For example, another device, such as a robot, may include a matching grabbing element such as an actuator to grab the handle, the hook, or the bar to grab the removable portion of the frame  105 . As another example, a robot actuator may include a magnet to grab the magnet that is connected to the removable portion of the frame  105 . 
     The gripping element  605  on the removable portion of the frame may be used by a human or a robot to remove the Peltier device and the detachable portion of the frame and insert another Peltier device that is connected to a gripping element and a similar detachable portion of the frame. In some embodiments, the water purification device  100  may be configured such that other components of the water purification device  100  may also be connected to the removable portion of the frame  105 . For example, and without limitations, the auxiliary heating element(s)  155 , in some embodiments, may be positioned such that the auxiliary heating element(s)  155  may also be connected to the removable portion of the frame  105 . 
     In some embodiments, the Peltier device, the corresponding removable portion of the frame, and a section of the insulator  185  that is connected to the removable portion of the frame may come off by pulling the gripping element  605  and may be replaced by another Peltier device, a corresponding removable portion of the frame, and a corresponding section of the insulator. 
     With reference to  FIG.  6 A , the feed water output channel  132  transfers the feed water out of the modular water purification device  100 . In the embodiments that transfer the purified water through the cascade, the purified water output channel  134  transfers the purified water out of the modular water purification device  100 . 
     With reference to  FIG.  6 B , the feed water input channel  132  may receive the feed water into the modular water purification device  100 . In the embodiments that transfer the purified water through the cascade, the purified water input channel  134  may receive the purified water into the modular water purification device  100 . 
     The modular water purification device may optionally include one or more solar panels.  FIG.  6 C  is an upper front perspective view of one example embodiment of a modular water purification device that includes one or more solar panels, according to various aspects of the present disclosure.  FIG.  6 D  is an upper rear perspective view of the modular water purification device of  FIG.  6 C , according to various aspects of the present disclosure. 
     With reference to  FIGS.  6 C and  6 D , the modular water purification device  150  may include one or more solar panels  610 . Each solar panel  610  may include one or more solar cells  615 . The solar panel(s)  610  may provide power to the modular water purification device  100  and/or to the cascade. 
     The solar panel(s)  610 , in some embodiments, may be connected by one or more support structures  617  to the frame  105 . In other embodiments, the solar panel(s)  610  may be directly connected to the frame  105 . 
     In some of the present embodiments, the solar panels may be attached to the frame by one or more foldable arms to facilitate shipping and moving around the frame and the solar panels as a single unit.  FIGS.  6 E and  6 F  are side elevational views of one example embodiment of a modular water purification device that includes one or more foldable solar panels, according to various aspects of the present disclosure. 
     With reference to  FIGS.  6 E and  6 F , the solar panel(s)  610  may be attached to the frame  105  by one or more fixed arms  618  and one or more foldable arms.  FIG.  6 E  shows the arm(s)  619  being folded (e.g., during transportation of the modular water purification device).  FIG.  6 F  shows the arm(s)  619  being extended (e.g., during the operation of the modular water purification device). Other components of  FIGS.  6 C- 6 F  may be similar to the components of  6 A- 6 B, described above. 
     With reference to  FIGS.  1 A- 1 B , the controller  150  may receive power from the cascade power feed  130  (e.g., through the connection  197 ) and may provide power to other components of the modular water purification device  100  through the local power feed  190 . The controller  150  may communicate with one or more external electronic devices through the cascade signal feed  136  and the connection  198 . In the embodiments that include an antenna, the controller  150  may communicate with one or more external electronic devices through the antenna. 
     The controller  150  may control the operation of and/or may receive signals from the valves  101 - 104 , the hot water level sensor(s)  121  measuring the feed water level  124 , the auxiliary heating element(s)  155 , the fan  180 , and the Peltier device  140  through the local signal feed  195 . 
     In the embodiment depicted in  FIGS.  1 A- 1 B , the controller  150  may receive power from the cascade power feed  130  (e.g., through the connection  197 ) and may provide power to other components of the modular water purification device  100  through the local power feed  190 . In other embodiments, the cascade power feed  130  may be directly connected to the local power feed  190 . 
     The controller  150  may control the operation of the valves  101 - 102 ,  103 - 104  ( FIG.  1 A ),  106  ( FIG.  1 B ), the auxiliary heating element(s)  155 , the Peltier device  140 , and/or the fan  180 . For example, as described further below, the controller  150  may send signals to turn theses device on/off (or open/close) during different cycles of the modular water purification device  100 . 
     The controller  150  may send and/or receive signals from one or more external electronic devices through the cascade signal feed  136  and the connector  198 . The controller  150  may send to and/or receive signals from the valves  101 - 102 ,  103 - 104  ( FIG.  1 A ),  106  ( FIG.  1 B ), the feed water level sensor(s)  121 , the humidity sensor(s)  122 , the temperature sensor(s)  123 , the Peltier device  140 , the auxiliary heating element(s)  155 , the fan  180 , the pressure sensors (not shown), the flow meter sensors (not shown), etc. The controller  150  may send and receive the signals through the local control signal feed  195 . 
       FIG.  7    is a state diagram  700  for a modular water purification device, according to various aspects of the present disclosure. With reference to  FIG.  7   , from a halt state  701 , the modular water purification device  100  ( FIGS.  1 A- 1 B ) may go through an initialization state  705 . After the initialization state  705 , the modular water purification device  100  may go to the fill state  710 , followed by the purification state  715 , followed by the wash state  720 . The modular water purification device  100  may repeatedly go through the fill  710 , purification  715 , and wash  720  states. 
     In some of the present embodiments, several modular water purification devices  100  may be connected to each other to form a cascade. The cascade, as described below with reference to  FIG.  8   , may include one or more rows. In some of the present embodiments, a cascade (or each row of a cascade) may include a controller that may receive measurements of different parameters (e.g., feed water level, feed water temperature, hot water vapor chamber temperature, etc.) of the modular water purification devices in the cascade (or a row of the cascade) and may determine the start of the end of each cycle  710 - 715  for the modular water purification devices. 
     With reference to  FIG.  7   , the state diagram  700  may be controlled by the controller  150  in each modular water purification device  100 , by the row controller for all modular water purification devices in a cascade row, and/or by the cascade controller for all modular water purification devices in the cascade. In the halt state  701 , the modular water purification device of some embodiments may turn off power to one or more components such as the Peltier device  140 , the auxiliary heating element(s)  155 , the fan  180 , etc. In some embodiments, the valves  101 - 104  and  106  may be kept closed. 
     From the halt state  701 , the modular water purification device  100  may receive a start initialization signal  721  (e.g., from the row controller, the cascade controller, or after the power is applied to the device) and may perform one or more initialization operations as described below with reference to  FIGS.  10 A- 10 B . After initialization, the modular water purification device  100  may receive a start fill cycle  722  signal (e.g., from the row controller or the cascade controller) to go to the fill state  710  to perform a fill cycle  710  and bring feed water into the device. From the fill state  710 , the modular water purification device  100  may receive a start purification cycle signal  723  (e.g., from the row controller or the cascade controller) to go to the purification state purify water. 
     From the purification state  715 , the modular water purification device  100  may receive a start wash cycle signal  724  (e.g., from the row controller or the cascade controller) to go to the wash state  720  to wash salt and other sediments from the device. From the wash state  720 , the modular water purification device  100  may receive a start fill cycle signal  725  (e.g., from the row controller or the cascade controller) to go back to the fill state  710 . From any of the initialization  705 , fill  710 , purification  715 , and wash  720  states, the modular water purification device  100  may receive a halt signal  780  and return to the halt state  701 . From any of the initialization  705 , fill  710 , purification  715 , and wash  720  states, the modular water purification device  100  may receive a pause signal  785  and may maintain the current state until another signal to change the state is received. 
     It should be noted that as long as a halt  780  signal or a pause signal  785  is not received, the modular water purification device  100  may continuously go through the fill cycle (e.g., when the modular water purification device  100  is in the fill state  710 ), followed by the water purification cycle (e.g., when the modular water purification device  100  is in the purification state  715 ), followed by the wash cycle (e.g., when the modular water purification device  100  is in the wash state  720 ), followed by the next fill cycle, water purification cycle, wash cycle, etc. 
       FIG.  8    is a functional block diagram of one example embodiment of a cascade of modular water purification devices that includes one or more rows of modular water purification devices, according to various aspects of the present disclosure. With reference to  FIG.  8   , the cascade  800  may include one or more rows  801 - 803 . Each row may include one or more modular water purification devices  100 . 
     Each row  801 - 803  of the cascade  800  may have a corresponding controller  811 - 813 . The controllers  811 - 813 , in some embodiments, may communicate with each other through wired or wireless connections (not shown). The controllers  811 - 813  may receive measurements of different parameters (e.g., feed water level, feed water temperature, hot water vapor chamber temperature, pressure, etc.) and/or status data from the controllers  150  in the corresponding row. The controllers  811 - 813  may determine the start of the end of each cycle  710 - 715  ( FIG.  7   ) for the modular water purification devices. 
     The controllers  811 - 813  may be (or may include) a processing unit such as a processor or microprocessor. The controllers  811 - 813  may include (or may be associated with) volatile memory and non-volatile storage. The controllers may send one or more signals to the controllers  150  in the corresponding rows to start or end each cycle. 
     Although the row controllers  811  are shown as external to the modular water purification devices  100 , in some embodiments, one of the controllers  150  in each row may be configured to operate as the row controller. Some embodiment may only include one controller (e.g., the controller  811 ) for controlling every row of the cascade  800 . In these embodiments, the cascade controller  811  may be connected to the cascade signal feed  136  of every row  801 - 803 . In some embodiments, one of the controllers  150  may be configured to operate as the controller for every row of the cascade  800 . 
       FIGS.  9 A- 9 B  are a flowchart illustrating an example process  900  for purifying water by a cascade of modular water purification devices, according to various aspects of the present disclosure. In some of the present embodiments, the process  900  may be performed by a controller  811 - 813  of  FIG.  8    (or by a controller  150  of a modular water purification device  100  that is configured to operate as a cascade or a row controller). 
     With reference to  FIGS.  9 A- 9 B , the process  900  may send (at block  905 ) the position of each modular water purification device in the row (or cascade) to the corresponding device. In some of the present embodiments, each modular water purification device  100  may have a unique identification code that may be assigned to the device either at the manufacture time or at the deployment time. The unique identification code of each device  100  may be stored in non-volatile storage on the device. 
     The position of each device  100  in a row  801 - 803  may be stored (e.g., at the deployment time of the cascade  800 ) in non-volatile storage accessible to the controllers  811 - 813  of the rows  801 - 803  (or the controller of the cascade  800 ). The controller of each row  801 - 803  (or the controller of the cascade  800 ) may send (at block  905 ) the position of each device  100  in a row  801 - 803  of the cascade to the corresponding device  100 . The controller  150  of each device may, therefore, may receive the information whether the corresponding device is the first device in a row, the last device in the row, or a device in a position other than the first or last device the row. 
     With further reference to  FIGS.  9 A- 9 B , the process  900  may send (at block  910 ) one or more signals to each modular water purification device  100  to perform initialization. The process  1000  ( FIGS.  10 A and  10 B ) describes the operations performed by each modular water purification device  100  in response to the signals received from the process  900 . 
     The process  900  may then receive (at block  915 ) status (e.g., whether or not the initialization is completed) from each modular water purification device  100  in the row (or the cascade). The process  900  may then determine (at block  920 ) whether the initialization is completed by the modular water purification device  100  in the row (or the cascade). When the process  900  determines (at block  920 ) that the initialization is not completed, the process  900  may return to block  915 , which was described above. 
     Otherwise, the process  900  may send (at block  925 ) one or more signals to each modular water purification device in the row (or cascade) to go to the fill state and start the fill cycle. During the fill cycle, the feed water reservoir  120  ( FIGS.  1 A- 1 B ) of modular water purification devices  100  may be filled by the feed water. 
     With reference to  FIGS.  9 A- 9 B , the process  900  may receive (at block  930 ) metrics including the level of the feed water and/or the level of the purified water from the modular water purification device in the row (or cascade). For example, the process  900  may receive the feed water level from the sensor(s)  41  of  FIGS.  1 A- 1 B . 
     The process  900  may determine (at block  935 ) whether the feed water has reached a first threshold level in the feed water reservoirs and/or a threshold amount of time has passed since the start of the fill cycle. Some of the present embodiments may turn on the power to the modular water purification devices&#39; Peltier device  140  ( FIGS.  1 A- 1 B ) and the auxiliary heating element(s)  155  prior to the completion of the fill cycle in order to heat the Peltier device  140  and the auxiliary heating element(s)  155 . Some embodiments may turn on the power to the fan  180  prior to the completion of the fill cycle in order to avoid any turbulence in the water vapor channel  116 . 
     With reference to  FIGS.  9 A- 9 B , when the process  900  determines (at block  935 ) that the feed water has not reached the first threshold level in the feed water reservoirs, the process  900  may proceed to block  930 , which was described above. Otherwise, the process  900  may send (at block  940 ) one or more signals to each modular water purification device in the row (or cascade) to turn on the power to the modular water purification devices&#39; Peltier device  140 , the auxiliary heating element(s)  155 , and the fan  180 . In some embodiments, a first threshold level of the feed water in the feed water reservoir  120  may be used to turn on the power to the Peltier device  140 , the auxiliary heating element(s)  155 , and the fan  180  and a second (and higher) threshold level of the feed water in the feed water reservoir  120  may be used to close the feed input and output valves to start the water purification cycle. 
     In some embodiments, instead of the first threshold level, a timeout since the start of the fill cycle may be used (e.g., when the metrics received in block  935  includes the flow of the feed water into the feed water reservoir  120 ) to turn on the power to the Peltier device  140 , the auxiliary heating element(s)  155 , and the fan  180 . 
     With continued reference to  FIGS.  9 A- 9 B , the process  900  may then receive (at block  945 ) metrics including the level of the feed water from the modular water purification device in the row (or cascade). The process  900  may then determine (at block  950 ) whether the feed water has reached a second threshold level in the feed water reservoirs. When the process  900  determines (at block  950 ) that the feed water has not reached the second threshold level in the feed water reservoirs, the process  900  may proceed to block  945 , which was described above. Otherwise, the process  900  may send (at block  955 ) one or more signals to each modular water purification device in the row (or cascade) to go to the water purification state and start the water purification cycle. 
     The process  900  may then receive (at block  960 ) the level of the feed water from the modular water purification device in the row (or cascade). As the feed water is evaporated from the feed water reservoir  120 , the level of feed water in the feed reservoir  120  may drop. The level of feed water in the feed reservoir  120  may, therefore, be used as an indication that not much feed water is left in the feed water reservoir  120  and the water purification cycle may be ended. 
     The process  900  may then determine (at block  965 ) whether the feed water has reached below a threshold level, or a threshold amount of time passed since the beginning of the purification cycle. When the process  900  determines (at block  965 ) that the feed water has not reached below a threshold level or a threshold amount of time has not passed since the beginning of the purification cycle, the process  900  may proceed to block  960 , which was described above. 
     Otherwise, the process  900  may send (at block  970 ) one or more signals to each modular water purification device in the row (or cascade) to go to the wash state and start the wash cycle. During the wash cycle the feed water is passed through the cascade in order to wash the salt and/or other sediments that are accumulated on the auxiliary heating element(s)  155  (or on the hot side  143  of the Peltier device  140  if the device does not include an auxiliary heating element(s)  155 ). 
     The process  900  may then receive (at block  975 ) the purification cycle&#39;s metrics (e.g., the amount of purified water collected during the purification cycle, amount of feed water flowed through teach device, etc.). The process  900  may then determine (at block  980 ) whether a threshold amount of time has passed since the beginning of the wash cycle and/or a threshold amount of feed water flowed through the cascade during the wash cycle. 
     When the process  900  determines (at block  980 ) that a threshold amount of time has not passed since the beginning of the wash cycle and/or a threshold amount of feed water has not flowed through the cascade during the wash cycle, the process  900  may proceed to block  975 , which was described above. Otherwise, the process  900  may proceed to block  925  to start a new fill cycle. 
       FIGS.  10 A and  10 B  are a flowchart illustrating an example process  1000  for purifying water by a modular water purification device, according to various aspects of the present disclosure. In some of the present embodiments, the process  1000  may be performed by the controller  150  ( FIGS.  1 A- 1 B ). The process  1000 , in some embodiments, may communicate with the process  900 . For example, the process  1000  may receive signals from the process  900  to start different cycles. The process  1000  may send status data and metrics to the process  900 . 
     With reference to  FIGS.  10 A and  10 B , the process  1000  may receive (at block  1005 ) the position of the module water purification device in a row of the water purification cascade. For example, the controller  150  ( FIG.  8   ) of a modular water purification device  100  in cascade  800  may receive the position of the device  100  in a row  811 - 803  of the cascade  800 . For example, the controller  150  may receive information whether or not the device  100  is the first or the last device in a row. 
     The process  1000  may turn off (at block  1010 ) the power to the water purification device&#39;s Peltier device, the auxiliary heating element(s), and the fan in response to receiving one or more signals to perform initialization. For example, the controller  150  ( FIGS.  1 A- 1 B ) may turn off the power to the water purification device&#39;s Peltier device  140 , the auxiliary heating element(s)  155 , and the fan  180  in response to the process  900  ( FIG.  9   ) sending the initialization signal(s) at block  910 . 
     With further reference to  FIGS.  10 A and  10 B , the process  1000  may determine (at block  1015 ) whether the modular water purification device is the first device in the row. In the embodiments that transfer the purified water through the cascade (e.g., the embodiment of  FIGS.  1 A and  2   ), when the process  1000  determines (at block  1015 ) that the modular water purification device is the first device in the row (e.g., based on the information received at block  1005 ), the process  1000  may close (at block  1020 ) the purified water input valve  103  and may open (at block  1020 ) the purified water output valve  104 . In the embodiments that transfer the purified water from each modular water purification device to one or more external reservoirs (e.g., the embodiment of  FIGS.  1 B and  3   ), when the process  1000  determines (at block  1015 ) that the modular water purification device is the first device in the row (e.g., based on the information received at block  1005 ), the process  1000  may open (at block  1020 ) the purified water output valve  106 . The process  1000  may then proceed to block  1030 , which is described below. 
     In the embodiments that transfer the purified water through the cascade (e.g., the embodiment of  FIGS.  1 A and  2   ), when the process  1000  determines (at block  1015 ) that the modular water purification device is not the first device in the row (e.g., based on the information received at block  1005 ), the process  1000  may open (at block  1025 ) the purified water input valve  103  and the purified output valve  104 . In the embodiments that transfer the purified water from each modular water purification device to one or more external reservoirs (e.g., the embodiment of  FIGS.  1 B and  3   ), when the process  1000  determines (at block  1015 ) that the modular water purification device is not the first device in the row (e.g., based on the information received at block  1005 ), the process  1000  may open the purified water output valve  106 . 
     The process  1000  may then determine (at block  1030 ) whether one or more signals are received (e.g., from block  925  of the process  900 ) to go to the fill state and start the fill cycle. When the process  1000  determines (at block  1030 ) that one or more signals are not received to start the fill cycle, the process  1000  may proceed to block  1030 , which was described above. Otherwise, the process  1000  may determine (at block  1035 ) whether the modular water purification device is the last device in the row. 
     When the process  1000  determines (at block  1035 ) that the modular water purification device is the last device in the row (e.g., based on the information received at block  1005 ), the process  1000  may open (at block  1040 ) the feed water input valve  101  ( FIGS.  1 A- 1 B ) and may close (at block  1040 ) the feed water output valve  102  to start the fill cycle by letting the feed water into the feed water reservoir  120 . The process  1000  may then proceed to block  1050 , which is described below. When the process  1000  determines (at block  1035 ) that the modular water purification device is not the last device in the row (e.g., based on the information received at block  1005 ), the process  1000  may open (at block  1045 ) the feed water input valve  101  ( FIGS.  1 A- 1 B ) and may open (at block  1045 ) the feed water output valve  102  to start the fill cycle by letting the feed water into the feed water reservoir  120  and by letting the feed water to be transferred to the next modular water purification device in the row. 
     The process  1000  may then send (at block  1050 ) performance metrics, including the level of the feed water to the row (or cascade) controller. As described above with reference to block  935  ( FIG.  9 A ), the process  900  may use the level of the feed water to determine whether the power to the Peltier device, the auxiliary heating element(s), and the fan may be turned on. 
     With further reference to  FIGS.  10 A and  10 B , the process  1000  may determine (at block  1055 ) whether one or more signals are received to turn on the power to the Peltier device, the auxiliary heating element(s), and the fan. For example, the process  1000  may receive the one or more signals to turn on the power to the Peltier device when the feed water reaches a first threshold in the feed water reservoir and/or a threshold amount of time is passed since the start of the fill cycle. 
     When the process  1000  determines (at block  1055 ) that one or more signals are received to turn on the power to the Peltier device, the auxiliary heating element(s), and the fan are not received, the process  1000  may proceed to block  1050 , which was described above. Otherwise, the process  1000  may turn on (at block  1060 ) the power to the Peltier device  140  ( FIGS.  1 A- 1 B ), the auxiliary heating element(s)  155 , and the fan  180 . 
     The process  1000  may then send (at block  1065 ) performance metrics, including the level of the feed water to the row (or cascade) controller. As described above with reference to block  950  ( FIG.  9 B ), the process  900  may use the level of the feed water to determine whether the water purification cycle may be started. 
     With further reference to  FIGS.  10 A and  10 B , the process  1000  may determine (at block  1070 ) whether one or more signals are received to go to the water purification state and start the water purification cycle. If not, the process  1000  may proceed to block  1065 , which was described above. Otherwise, the process  1000  may close (at block  1080 ) the feed water input and output valves to start the purification cycle. For example, the controller  150  may close the valves  101  and  102  ( FIGS.  1 A- 1 B ) to start the purification cycle. 
     The process  1000  may then determine (at block  1085 ) the purification cycle&#39;s metrics (e.g., the amount of purified water collected during the purification cycle, amount of feed water flowed through teach device, etc.) and may send the metrics to the row (or cascade) controller. The process  1000  may then determine (at block  1090 ) whether one or more signals are received to go to the wash state and start the wash cycle. If not, the process  1000  may proceed to block  1085 , which was described above. Otherwise, the process  1000  may turn off (at block  1092 ) the power to the modular water purification devices&#39; Peltier device, auxiliary heating element(s), and fan. 
     The process  1000  may open (at block  1095 ) the feed water input valve  101  and the feed water output valve  102  to wash the salt and/or other sediments from the bottom of the feed water reservoir. The process  1000  may determine (at block  1097 ) the purification cycle&#39;s metrics (e.g., the amount of feed water passed through the device, etc.) and may send the metrics to the row (or cascade) controller. 
     The process  1000  may then determine (at block  1098 ) whether one or more signals are received to go to the fill state and start the fill cycle. If not, the process  1000  may proceed to block  1097 , which was described above. Otherwise, the process  1000  may proceed to block  1035 , which was described above to start a new fill cycle. 
     In some of the present embodiments, the controller  150  in each modular water purification device  100  may send status data and performance metrics to one or more external electronic devices and/or may receive signals from one or more external electronic devices.  FIG.  11    is a functional block diagram of one example embodiment of a cascade of modular water purification devices with one or more control and monitoring servers and a robot for replacing Peltier devices, according to various aspects of the present disclosure. For simplicity only one row  801  of the cascade  800  is shown. It should be understood that the cascade  800  of  FIG.  11    may include several rows of modular water purification devices similar to rows  801 - 803  of the cascade  800  of  FIG.  8   . 
     The cascade of  FIG.  11    may include one or more rows of modular water purification devices  100 . For simplicity, only one row of modular water purification devices  100  is shown in  FIG.  11   . With reference to  FIG.  11   , the controllers  150  may communicate data and status with the row controller  811  through the cascade signal feed  136 . The row controller  811  may communicate wirelessly with one or more control and monitoring servers  1160  through one or more networks  1170 . In some embodiments, the row controller  811  may include one or more antennas  1120  and the server(s)  1160  may include one or more antennas  1110  and may wirelessly communicate with each other (e.g., through one or more networks  1170 ). In some embodiments, the row controller  811  and the server(s)  1160  may communicate through a wired link. 
     The server(s)  1160  may generate reports, may provide one or more user interfaces to display the status and the performance metrics of the cascade  801 . Each controller  150  may receive health, performance, and/or status information from different components of the corresponding modular water purification device  100 . For example, the controller  150  may receive health, performance, and/or status information from the valves  101 - 104  and  106  ( FIGS.  1 A- 1 B,  2   , and  3 ), the water level sensors  121  and  305 , the humidity sensors  122 , the temperature sensors  123 , the Peltier device  140 , the auxiliary heating element(s)  155 , and the fan  180 . 
     The controller  150  may send the health, performance, and/or status information to the row controller  811  through the cascade signal feed  136 . The row controller  811  may send the health, performance, and/or status information to the server(s)  1160  through the wired and/or wireless links. 
     The controller  150 , in some embodiments, may determine the health status of the Peltier device when the Peltier device is turned on. The controller  150 , in some embodiments, may compare the current drawn by the Peltier device with a current range and may determine that the Peltier device has failed if the current drawn by the Peltier device is outside the range. The current range may depend on the size of the Peltier device. The controller  150 , for example and without limitation, may receive the current range at the initialization state, at the configuration time of the modular water purification device, etc., and may store the current range in non-volatile memory inside the modular water purification device. 
     The controller  150 , in some embodiments, may determine the health status of the Peltier device by comparing the temperature of the cold side of the Peltier device with a threshold temperature a threshold time period after the Peltier device is turned on. If the temperature of the cold side of the Peltier device is not lower than the threshold temperature within the threshold time period, the controller  150  may determine that the Peltier device has failed. 
     As described above, in some embodiments, the modular water purification device  100  may be configured such that other components of the modular water purification device  100 , such as the auxiliary heating element(s)  155  may also be connected to the removable portion of the frame. In these embodiments, the controller  150  may determine the health status of the heating element, for example, by receiving temperature measurements from one or more temperature sensors (not shown) that may be connected to, or be in a vicinity of, the auxiliary heating element(s)  155 . The controller  150  may determine that the auxiliary heating element(s) have failed when the temperature of the auxiliary heating element(s)  155  do not reach a threshold temperature a predetermined time after power is applied to the auxiliary heating element(s)  155 . 
     When the Peltier device  120  (or the auxiliary heating element(s)  155 ) in a modular water purification device  100  fails, the controller  150 , the row controller  811 , and/or the server(s)  1160  may send a signal to a robot  1150  to replace the failed Peltier device  140 . The robot  1150  may include one or more antennas  1115  and may wirelessly communicate with controller  150 , the row controller  811 , and/or the server(s)  1160  (e.g., through the network(s)  1170 ). The robot  1150  may communicate with the row controller  811  and/or the server(s)  1160  through a wired link. 
     As described with reference to  FIGS.  6 A- 6 B , the Peltier device  140  may be connected to a removable portion of the frame  105 , which may be connected to a gripping element  605  for the easy removal and insertion of the Peltier device into the frame  105 . In some of the present embodiments, the removable portion of the frame (e.g., the portion on side  503  that is directly under the insulator  185 ) may be used by the robot  1150  to remove the Peltier device and the detachable portion of the frame and insert another Peltier device that is connected to a gripping element and a similar detachable portion of the frame. 
     The robot  1150  may include a remotely controlled griping element (not shown) that may be used to grab the gripping element  605  ( FIGS.  6 A- 6 D ) of the removable portion of the frame  105  of the water purification device  100 . For example, in the embodiments that the gripping element  605  of the water purification device  100  is a handle, a hook, or a bar, the robot&#39;s gripping element may be an actuator that includes a jaw that may be opened or closed in response to signals received by the robot to open or close the jaw, respectively. The jaw may be opened to grab the gripping element  605  of the removable portion of the water purification device  100 . The jaw may be closed to keep hold of the gripping element  605  of the removable portion of the water purification device  100 . The actuator of the robot may include an arm attached to the jaw. After the jaw grabs the gripping element  605  of the water purification device  100 , the robot may receive one or more signals to move the arm away from the frame  105  and remove the removable portion of the frame  105  after the jaw grabs the gripping element  605 . 
     As another example, in the embodiments that the gripping element  605  of the water purification device  100  is a magnet, the robot&#39;s gripping element may also be (or may include) a magnet may be attached to the magnet of the water purification device  100 . The robot may then remove the removable portion of the water purification device  100  by moving the arm away from the water purification device  100  in response to receiving one or more signals to move the arm. 
     Some embodiments may include a grid of rails  1105  in front of each row of the cascade  800 . The location of each modular water purification device  100  in the cascade may be known by the cascade row and/or by the server(s)  1160 . The location of each modular water purification device  100 , in some embodiments, may be the coordinates of the modular water purification device  100  within the rail grid of the cascade  800 . For a cascade that may include several rows and each row may include several modular water purification devices  100 , the coordinates of each modular water purification device  100  may include the cascade row  801 - 803  ( FIG.  8   ) where the modular water purification device  100  is located and the position of the modular water purification device  100  in the corresponding cascade. 
     The coordinates of a modular water purification device  100  within the cascade may be known by the control and monitoring server(s)  1160 , by the corresponding cascade row controller  811 , and/or by the corresponding controller  150  of the modular water purification device  100 . In some embodiments, each modular water purification device  100  may have a unique identification, which may be used by the control and monitoring server(s)  1160 , by the corresponding cascade row controller  811 , and/or by the corresponding controller  150  to map the identification to the exact location of the modular water purification device  100  within the rail grid. 
     In some embodiments, the rails  1105  that are in front of each cascade row may be connected to each other and one robot  1150  may move over the rails  1105 . In other embodiments, each cascade row may include a separate robot that move in front of the corresponding rail  1105  of the cascade row. In either embodiment, the robot  1150  may be moved over the rail  1150  to the exact location where a modular water purification device  100  is located. 
     When a controller  150  of a modular water purification device  100  determines that the corresponding Peltier device  140  and/or the corresponding auxiliary heating element(s)  155  have failed, the controller  150  may send a health status to the corresponding cascade row controller  811 . The health status may include the identification of the modular water purification device  100  from which the location of the modular water purification device  100  on the rail  1105  may be identified. 
     The cascade row controller  811  may send the health status to the server(s)  1160 . In some embodiments, the server(s)  1160  may send one or more signals to the cascade row controller  800  to replace the failed Peltier device  140  and/or the failed auxiliary heating element(s)  155 . In other embodiments, the cascade row controller  811  may determine that the failed Peltier device  140  and/or the failed auxiliary heating element(s)  155  has to be replaced after receiving the health status from the controller  150  that has detected the failure. 
     The row controller  811  may then send one or more signals to the robot  1150  to move in front of the removable portion of the modular water purification device  100  that has reported the failure. For example, the robot  1150  may move over the rail  1105  to the coordinates of the modular water purification device  100  within the rail grid. The robot, in some embodiments, may include one or more rolling elements such as, for example, and without limitations, one or more wheels, one or more ball bearings, one or more cylinders that may rotate around a shaft, etc., that may move the robot along the rail  1105 . 
     As described above, the robot  1150  may include a gripping element (not shown) such as an actuator or a magnet. The row controller  811  may send one or more signals to the robot to attach the gripping element of the robot to the gripping element  605  ( FIGS.  6 A- 6 D ) of the removable portion of the water purification device. The row controller  811  may send one or more signals to the robot to pull out the removable portion by moving the actuator of the robot away from the water purification device. 
     The robot  1150  may have access to one or more functional Peltier devices  1190 . Each functional Peltier device  1190  may be attached to a corresponding removable portion of a frame  105  that may include a grabbing element  605  ( FIGS.  6 A- 6 D ). The row controller  811  may send one or more signals to the robot to grab the gripping element of one of the functional Peltier devices  1190 . The row controller  811  may send one or more signals to the robot to move the robot&#39;s actuator towards the water purification device to insert the functional Peltier device  190 , and the attached removable portion of the frame, into the frame of the modular water purification device. In addition to, or in lieu of the cascade row controller  81 , the server(s)  1160  may send the above-mentioned signals to the robot to move over the rail  1105  in front of the modular water purification device  100  that has reported a failure in the corresponding Peltier device and/or a failure in the auxiliary heating elements ( 155 ), remove the removable portion of the frame and the attached faulty Peltier device, and replace them with a functional Peltier device and a corresponding removable portion of the frame. 
     The water purification cascade in different embodiments may receive power from different sources.  FIG.  12    is a front elevational view of one example embodiment of a cascade of modular water purification devices that receives electricity from solar panels associated with one or more of the modular water purification devices, according to various aspects of the present disclosure. 
     As described with reference to  FIGS.  6 A- 6 B , the modular water purification device  100  may include one or more solar panels  610 . The solar panels  610  may generate power and may provide power to the cascade&#39;s power feed  130  through a power feed  1210 . A portion of the generated power may be stored (e.g., in one or more capacitors) for use when solar or ambient lights are not available. 
       FIG.  13    is a front elevational view of one example embodiment of a cascade of modular water purification devices that receives electricity from one or more solar panels, according to various aspects of the present disclosure. With reference to  FIG.  13   , the cascade may include a set of solar panels  1305  that are separate from the modular water purification devices  100 . The solar panels  1305  may generate power and may provide power to the cascade&#39;s power feed  130  through a power feed  1310 . A portion of the generated power may be stored (e.g., in one or more capacitors) for use when solar or ambient lights are not available. 
       FIG.  14    is a front elevational view of one example embodiment of a cascade of modular water purification devices and different sources of energy that may be used by the cascade, according to various aspects of the present disclosure. With reference to  FIG.  14   , the power generator  1405  may generate power from one or more sources of energy such as, without limitation, thermal, wind, marine, hydroelectric, osmosis, biomass, etc. The power generated by the power generator  1405  may be connected to the cascade power feed  130  through a power feed  1410 . 
       FIG.  15    is a front elevational view of one example embodiment of a cascade of modular water purification devices that receives energy from a utility power line, according to various aspects of the present disclosure. With reference to  FIG.  15   , the utility power line  1510  may come from a municipal or industrial utility power line. The cascades in  FIGS.  12 - 13    may use any of the power source described with reference to  FIGS.  14 - 15    in addition to using the power generated by the solar panels. 
     As described above with reference to  FIG.  8   , a cascade  800  may include one or more rows  801 - 803  and each row may include one or more modular water purification devices  100 . In the embodiments that have one row with one modular water purification device, the single modular water purification device may be used as a standalone water purification device. 
       FIG.  16    is a front elevational view of one example embodiment a single modular water purification device used as a standalone water purification device, according to various aspects of the present disclosure. With reference to  FIG.  16   , the water purification device  1600  may include only one modular water purification device  100 . The water purification device  1600  may be used as a portable device or may be anchored, for example, to a platform. 
     Similar to the modular water purification devices described above, the modular water purification device  100  of  FIG.  16    go through the states  701 ,  705 ,  710 ,  715 , and  720 , as described above with reference to  FIG.  7   . For example, the modular water purification device  100  of  FIG.  16    may repeatedly go through a fill cycle, followed by a water purification cycle, followed by a wash cycle. During the fill cycle, the feed water reservoir  120  may be filled with feed water. During the water purification cycle, the feed water may be vaporized and condensed into purified water. The purified water may be transferred out of the water purification device  1600 . 
     The valve  101  may bring feed water through the feed water input pipe (or channel)  131 . Examples of the feed water include, without any limitations, tap water that may require purification, salt water from the oceans, salt water from lakes, brackish water from estuaries and aquifers, brine from the Earth&#39;s surface and crust, fresh water from rivers, lakes, well, etc. 
     The purified water that is collected at the bottom of the frame  105  may be transferred out of the water purification device  1600  through the valve  106  and the purified water output channel  135 . Some embodiments may include a mineral mixer  1605  on the purified water output  135  to add minerals to the purified water. The mineral mixer  1605  may be, for example, and without limitations, a remineralization filter. The mineral mixer  1605  may add different mineral, such as, for example, and without limitations, compound of calcium, magnesium, potassium, etc. 
     In addition to, or in lieu of, the valve  106 , some embodiments may include another valve  1601  after the mineral mixer  1605 . Although only one valve  106  and one purified water output channel  135  are shown in  FIG.  16   , the water purification device  1600 , in some embodiments, may have several purified water output channels and the corresponding valves for transferring the purified water out of the device. 
     With further reference to  FIG.  16   , the valve  1632  may take the feed water out of the water purification device  1600  during the wash cycle. The water purification device  1600  may receive power from a power feed  1630 . Similar to the embodiments described above, the modular water purification device  100  of  FIG.  16    may receive power from one or more sources such as, for example, and without limitations, a utility power line coming from a municipal or industrial utility power line (e.g., as described above with reference to  FIG.  15   ), one or more solar panels associated with one or more of the modular water purification devices (e.g., as described above with reference to  FIGS.  6 C- 6 F and  12   ), from one or more solar panels that are separate from the modular water purification devices  100  (e.g., as described above with reference to  FIG.  13   ), from one or more sources of energy such as, without limitation, thermal, wind, marine, hydroelectric, osmosis, biomass, etc. (e.g., as described above with reference to  FIG.  14   ). 
     In some embodiments, the controller  150  may receive the power feed  1630  and may distribute the power to other components of the modular water purification device  100  through the local power feed  190 . In some embodiments, the controller  150  may receive the signal feed  1636  and may send control signals to other components of the modular water purification device  100  through the local control signal feed  195 . 
     The modular water purification device  100  may include a flow meter  127  (e.g., inside the purified water output channel  135  or integrated with one of the valves  106  or  1601 ) and/or arrays of light detectors and LEDs, as described above with reference to  FIG.  1 B , for measuring the flow and/or the level  125  of the purified water. Other components of the modular water purification device  100  of  FIG.  16    may be similar to the corresponding components of the water purification device  100  of  FIGS.  1 A and  1 B . 
     Some of the above-described features and applications may be implemented as software processes that are specified as a set of instructions recorded on a computer readable storage medium (also referred to as computer readable medium). When these instructions are executed by one or more processing unit(s) (e.g., one or more processors, cores of processors, or other processing units), they cause the processing unit(s) to perform the actions indicated in the instructions. Examples of computer readable media include, but are not limited to, CD-ROMs, flash drives, RAM chips, hard drives, EPROMs, etc. The computer readable media does not include carrier waves and electronic signals passing wirelessly or over wired connections. 
     In this specification, the term “software” is meant to include firmware residing in read-only memory or applications stored in magnetic storage, which may be read into memory for processing by a processor. Also, in some embodiments, multiple software inventions may be implemented as sub-parts of a larger program while remaining distinct software inventions. In some embodiments, multiple software inventions may also be implemented as separate programs. Finally, any combination of separate programs that together implement a software invention described here is within the scope of the invention. In some embodiments, the software programs, when installed to operate on one or more electronic systems, define one or more specific machine implementations that execute and perform the operations of the software programs. 
       FIG.  18    is a functional block diagram of one example embodiment of an electronic system  1800  with which some embodiments of the invention (e.g., the controllers, the processing units, the robots, the servers, etc.) are implemented. The electronic system  1800  may be used to execute any of the control, virtualization, and/or operating system applications described above. The electronic system  1800  may be a computer (e.g., desktop computer, personal computer, tablet computer, server computer, mainframe, blade computer etc.), a controller, a microcontroller, or any other sort of electronic device. Such an electronic system includes various types of computer readable media and interfaces for various other types of computer readable media. Electronic system  1800  includes a bus  1805 , processing unit(s)  1810 , a system memory  1820 , a read-only memory (ROM)  1830 , a permanent storage device  1835 , input devices  1840 , and output devices  1845 . 
     The bus  1805  may collectively represent all system, peripheral, and chipset buses that communicatively connect the numerous internal devices of the electronic system  1800 . For example, the bus  1805  may communicatively connect the processing unit(s)  1810  with the read-only memory  1830 , the system memory  1820 , and the permanent storage device  1835 . 
     From these various memory units, the processing unit(s)  1810  may retrieve instructions to execute and data to process in order to execute the processes of the invention. The processing unit(s) may be a single processor or a multi-core processor in different embodiments. 
     The read-only-memory  1830  may store static data and instructions that are needed by the processing unit(s)  1810  and other modules of the electronic system. The permanent storage device  1835 , on the other hand, may be a read-and-write memory device. This device is a non-volatile memory unit that stores instructions and data even when the electronic system  1800  is off. Some embodiments of the invention use a mass-storage device (such as a magnetic or optical disk and its corresponding disk drive) as the permanent storage device  1835 . 
     Other embodiments may use a removable storage device (such as a flash drive, etc.) as the permanent storage device. Like the permanent storage device  1835 , the system memory  1820  may be a read-and-write memory device. However, unlike storage device  1835 , the system memory may be a volatile read-and-write memory, such as random access memory. The system memory may store some of the instructions and data that the processor needs at runtime. In some embodiments, the invention&#39;s processes may be stored in the system memory  1820 , the permanent storage device  1835 , and/or the read-only memory  1830 . From these various memory units, the processing unit(s)  1810  may retrieve instructions to execute and data to process in order to execute the processes of some embodiments. 
     The bus  1805  may also connect to the input and output devices  1840  and  1845 . The input devices may enable the user to communicate information and select commands to the electronic system. The input devices  1840  may include alphanumeric keyboards and pointing devices (also called “cursor control devices”). The output devices  1845  may display images generated by the electronic system. The output devices may include printers and display devices, such as cathode ray tubes (CRT) or liquid crystal displays (LCD). Some embodiments may include devices, such as a touchscreen, that function as both input and output devices. 
     Finally, as shown in  FIG.  18   , bus  1805  also couples electronic system  1800  to a network  1825  through a network adapter (not shown). In this manner, the computer may be a part of a network of computers (such as a local area network (“LAN”), a wide area network (“WAN”), an Intranet, or a network of networks, such as the Internet. Any or all components of the electronic system  1800  may be used in conjunction with the invention. 
     Some embodiments may include electronic components, such as microprocessors, storage, and memory, that store computer program instructions in a machine-readable or computer-readable medium (alternatively referred to as computer-readable storage media, machine-readable media, or machine-readable storage media). Some examples of such computer-readable media include RAM, ROM, read-only compact discs (CD-ROM), recordable compact discs (CD-R), rewritable compact discs (CD-RW), read-only digital versatile discs (e.g., DVD-ROM, dual-layer DVD-ROM), a variety of recordable/rewritable DVDs (e.g., DVD-RAM, DVD-RW, DVD+RW, etc.), flash memory (e.g., SD cards, mini-SD cards, micro-SD cards, etc.), magnetic and/or solid state hard drives, read-only and recordable Blu-Ray® discs, ultra density optical discs, any other optical or magnetic media, and floppy disks. The computer-readable media may store a computer program that is executable by at least one processing unit and includes sets of instructions for performing various operations. Examples of computer programs or computer code include machine code, such as is produced by a compiler, and files including higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter. 
     While the above discussion primarily refers to microprocessor or multi-core processors that execute software, some embodiments may be performed by one or more integrated circuits, such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some embodiments, such integrated circuits execute instructions that are stored on the circuit itself. Some of the present embodiments may include flexible circuit, also referred to as flexible printed circuit boards (PCBs). The flexible circuits may provide dynamic flexing and increased heat dissipation and may be used in the embodiments that require circuits with smaller footprint, increased package density, more tolerance to vibrations, and/or less weight. 
     As used in this specification, the terms “computer”, “server”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. For the purposes of the specification, the terms display or displaying means displaying on an electronic device. As used in this specification, the terms “computer readable medium,” “computer readable media,” and “machine readable medium” are entirely restricted to tangible, physical objects that store information in a form that is readable by a computer. These terms exclude any wireless signals, wired download signals, and any other ephemeral or transitory signals. 
     While the invention has been described with reference to numerous specific details, one of ordinary skill in the art will recognize that the invention may be embodied in other specific forms without departing from the spirit of the invention. In addition, a number of the figures (including  FIGS.  9 A,  9 B,  10 A, and  10 B ) conceptually illustrate processes. The specific operations of these processes may not be performed in the exact order shown and described. The specific operations may not be performed in one continuous series of operations, and different specific operations may be performed in different embodiments. Furthermore, the process could be implemented using several sub-processes, or as part of a larger macro process. 
     The above description presents the best mode contemplated for carrying out the present embodiments, and of the manner and process of practicing them, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which they pertain to practice these embodiments. The present embodiments are, however, susceptible to modifications and alternate constructions from those discussed above that are fully equivalent. Consequently, the present invention is not limited to the particular embodiments disclosed. On the contrary, the present invention covers all modifications and alternate constructions coming within the spirit and scope of the present disclosure. For example, the steps in the processes described herein need not be performed in the same order as they have been presented and may be performed in any order(s). Further, steps that have been presented as being performed separately may in alternative embodiments be performed concurrently. Likewise, steps that have been presented as being performed concurrently may in alternative embodiments be performed separately.