Particulate filter and method for removing particulates from a particulate filter

Abstract

In one example, a particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) includes a porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) including a first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) and a second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214). The porous filter substrate is configured to filter gas flowing through the porous filter substrate (110, 210, 310, 510, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) between a first surface and a second surface. A plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) are coupled to the porous filter substrate. The plurality of conductors are generally parallel to one another along the porous filter substrate. The particulate filter also includes a plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source (124, 224, 324, 624, 824, 1024, 1224). The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signals from the input signal source.

Description

[Technical field]

[0001]

[0001] The present disclosure relates generally to filters, and more particularly to filters having particulate mitigation systems. [Background technology]

[0002]

[0002] A particulate filter is a device that removes solid particulates, such as dust, pollen, mold, and bacteria, from a gas, such as air. One type of particulate filter uses mechanical filtration to capture and separate the particulates from the gas as the gas flows through the particulate filter. Summary of the Invention

[0003] In one example, the particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. A plurality of conductors are coupled to the porous filter substrate. The plurality of conductors are generally parallel to one another along the porous filter substrate. The particulate filter also includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0004]

[0004] In another example, a method of removing particulates from a particulate filter includes receiving voltage signals from an input signal source at a plurality of input nodes of the particulate filter. The particulate filter includes a porous filter substrate and a plurality of conductors coupled to the porous filter substrate. The porous filter substrate is configured to filter gas flowing between a first surface of the porous filter substrate and a second surface of the porous filter substrate. The plurality of conductors are generally parallel to one another along the porous filter substrate. The plurality of input nodes are in signal communication with the plurality of conductors. The method further includes generating an electric field on at least one of the first surface or the second surface of the porous filter substrate using the voltage signals on the plurality of conductors. The method also includes removing particulates from at least one of the first surface or the second surface using the electric field.

[0005] In another example, a method of manufacturing a particulate filter includes coupling a porous filter substrate to a frame. The porous filter substrate includes a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. The method also includes coupling a plurality of conductors to the porous filter substrate such that the plurality of conductors are substantially parallel to one another along the porous filter substrate, and forming a plurality of input nodes in signal communication with the plurality of conductors to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving voltage signals from the input signal source.

[0006]

[0006] In another example, a filter system includes a particulate filter and an electromagnetic field generator. The particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. The particulate filter also includes a plurality of conductors coupled to the porous filter substrate. The conductors are generally parallel to each other along the porous filter substrate. The particulate filter further includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0007]

[0007] The electromagnetic field generator is disposed along the gas flow path upstream of the particulate filter, the electromagnetic field generator operable to generate an electromagnetic field configured to charge particulates in the gas before the gas flows through the porous filter substrate.

[0008] According to another example, a filter system includes a particulate filter, a gas recirculation system, and a controller. The particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate in a direction from the first surface to the second surface. The particulate filter also includes a plurality of conductors coupled to the porous filter substrate. The plurality of conductors are generally parallel to one another along the porous filter substrate. The particulate filter further includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving voltage signals from the input signal source.

[0009] The gas recirculation system includes a duct having an inlet and an outlet. The inlet of the duct is configured to receive into the duct gas that exits the particulate filter at the second surface. The outlet of the duct is configured to exit the duct gas to the particulate filter at the first surface. The controller is in communication with the input signal source. The controller is configured to (i) cause the input signal source to provide a first voltage signal while the gas flows through the porous filter substrate at a first time, and (ii) cause the input signal source to provide a second voltage signal while the gas flows again through the porous filter substrate after the gas has been recirculated by the gas recirculation system. The first voltage signal is different from the second voltage signal.

[0010] According to another example, a filter system includes a particulate filter and a gas mover. The particulate filter includes a porous filter substrate including a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface. The particulate filter also includes a plurality of conductors coupled to the porous filter substrate. The conductors are generally parallel to one another along the porous filter substrate. The particulate filter also includes a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving voltage signals from the input signal source.

[0011]

[0011] The gas mover is disposed along the gas flow path upstream of the particulate filter, the gas mover being operable to create turbulence in the gas before the gas flows through the porous filter substrate.

[0012]

[0012] The discussed features, functions, and advantages can be achieved individually in various examples or can be combined in other examples, which can be seen in further detail by referring to the following description and drawings.

[0013]

[0013] The novel features believed to be characteristic of the illustrative examples are set forth in the appended claims. However, the illustrative examples, as well as the preferred mode of use, further objects and explanations thereof, will best be understood by reference to the following detailed description of illustrative examples of the present disclosure when read in conjunction with the accompanying drawings. [Brief description of the drawings]

[0014] [Figure 1] 1 shows a simplified block diagram of a particulate filter according to an example. [Diagram 2]

[0015] 1 shows a perspective view of a particulate filter according to another example. [Diagram 3]

[0016] 1 shows a perspective view of a particulate filter according to another example. [Figure 4A]

[0017] A perspective view of another example of a particulate filter is shown. [Figure 4B]

[0018] 1 shows a perspective view of a particulate filter according to another example. [Diagram 5]

[0019] 1 shows a perspective view of a particulate filter according to another example. [Figure 6]

[0020] As an example, a perspective view of a particulate filter including an actuator is shown. [Figure 7A]

[0021] 1 illustrates a cross-sectional view of a particulate porous filter substrate and a conductor according to an example. [Figure 7B]

[0022] 13 shows a cross-sectional view of a particulate porous filter substrate and a conductor according to another example. [Figure 7C]

[0023] 13 shows a cross-sectional view of a particulate porous filter substrate and a conductor according to another example. [Figure 7D]

[0024] 13 shows a cross-sectional view of a particulate porous filter substrate and a conductor according to another example. [Figure 8]

[0025] 1 illustrates a simplified block diagram of a filter system, according to an example. [Figure 9A]

[0026] 9 illustrates a side view of the filter system shown in FIG. 8, according to an example. [Figure 9B]

[0027] 9B illustrates an electromagnetic field generator of the filter system shown in FIG. 9A, according to an example. [Figure 10]

[0028] 1 illustrates a simplified block diagram of a filter system, according to an example. [Figure 11]

[0029] 11 illustrates a perspective view of the filter system shown in FIG. 10 according to another example. [Figure 12]

[0030] 1 illustrates a simplified block diagram of a filter system, according to an example. [Figure 13]

[0031] 13 illustrates one implementation of the filter system shown in FIG. 12, according to an example. [Figure 14]

[0032] 1 illustrates a flow chart of a method for removing particulates from a particulate filter, according to an example. [Figure 15]

[0033] 15 shows a flow chart of a method for removing particulates from a particulate filter for use in the method shown in FIG. 14. [Figure 16]

[0034] 16 shows a flow chart of a method for removing particulates from a particulate filter for use in the method shown in FIG. 15. [Figure 17]

[0035] 16 shows a flow chart of a method for removing particulates from a particulate filter for use in the method shown in FIG. 15. [Figure 18]

[0036] 18 shows a flow chart of a method for removing particulates from a particulate filter for use in the method shown in FIG. 17. [Figure 19]

[0037] 15 shows a flow chart of a method for removing particulates from a particulate filter for use in the method shown in FIG. 14. [Figure 20]

[0038] 15 shows a flow chart of a method for removing particulates from a particulate filter for use in the method shown in FIG. 14. [Figure 21]

[0039] 15 shows a flow chart of a method for removing particulates from a particulate filter for use in the method shown in FIG. 14. [Figure 22]

[0040] 1 shows a flow chart of a method for making a particulate filter, according to an example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015]

[0041] The disclosed examples are described more fully below with reference to the accompanying drawings. Some, but not all, of the disclosed examples are shown. Indeed, several different examples may be described, and should not be construed as being limited to the examples set forth herein. Rather, these examples are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0016]

[0042] The terms "approximately" or "substantially" with respect to a quantity or measurement described herein do not require that the described characteristic, parameter, or value be achieved exactly, but may occur in an amount that does not exclude the effect that the characteristic is intended to provide, including, for example, tolerances, deviations or variations, measurement errors, limitations in measurement precision, and other factors known to those of skill in the art.

[0017]

[0043] As used herein, the terms "greater than" and "less than" are intended to have their common meaning. Thus, if a first value is greater than a second value by any amount, then the first value is greater than the second value. Similarly, if a first value is somewhat less than the first value, then the first value is less than the second value.

[0018]

[0044] As described above, the particulate filter can capture and separate particulates from gas when the gas flows through the particulate filter. For example, the particulate filter can include a porous filter substrate that can capture and hold particulates in the gas by the mechanism of collision, interception, and / or diffusion. Over the life of the particulate filter, particulates can accumulate on the porous filter substrate and can impede the flow of gas through the particulate filter (i.e., particulate accumulation can clog the particulate filter). Thus, the accumulated particulates can reduce the efficiency of the particulate filter.

[0019]

[0045] One approach to address the loss of efficiency of particulate filters due to particulate buildup is to manually clean the porous filter substrate. This approach can be labor-intensive, time-consuming, and / or inefficient. Another approach is to remove the existing porous filter substrate and replace it with a new porous filter substrate. This approach can be costly, labor-intensive, and / or time-consuming. Furthermore, in some cases, the approach to replacing the porous filter substrate may include storing multiple replacement filter substrates on-site, and thus may include difficult storage space and supply logistics considerations. For example, storing multiple replacement filter substrates for spacecraft applications may provide challenges to meet space constraints and / or weight limit considerations associated with efficiently operating a spacecraft.

[0020]

[0046] In an example, a particulate filter is described that can address one or more of the above-mentioned issues related to particulates accumulating on the particulate filter over time. Specifically, in an example, the particulate filter can include a plurality of conductors coupled to a porous filter substrate and configured to generate an electric field on at least one of a first surface or a second surface of the porous filter substrate in response to a voltage signal from an input signal source. When the electric field is generated, the electric field can repel and remove particulates accumulated on the porous filter substrate and / or repel the particulates to prevent the particulates from accumulating on the porous filter substrate. In this manner, the particulate filter can clean the porous filter substrate without (or with reduced) manual intervention. This helps provide more efficient, frequent, and / or quicker cleaning of the porous filter substrate. Furthermore, the particulate filter described herein can address issues related to replacing the porous filter substrate and / or storing the replacement porous filter substrate described above.

[0021]

[0047] Referring now to FIG. 1, a particulate filter 100 for filtering one or more particulates in a gas is shown according to an example. In an example, the particulates may include dust (e.g., terrestrial dust and / or dust from an extraterrestrial environment), mold spores, bacteria, microorganisms, fabric lint, food debris, metal debris, wood debris, and / or plastic debris. Also, in an example, the gas may include air, nitrogen, hydrogen, oxygen, and / or carbon dioxide. The particulate filter 100 may be used in various environments to filter gas and remove particulates. As an example, the particulate filter 100 may be used to filter gas in a ventilation system, a spacecraft, a space habitat, and / or a space suit.

[0022]

[0048] As shown in FIG. 1, the particulate filter 100 includes a porous filter substrate 110 having a first surface 112 and a second surface 114. Generally, the porous filter substrate 110 is configured to filter a gas flowing through the porous filter substrate 110 between the first surface 112 and the second surface 114 by removing particles from the gas. For example, the porous filter substrate 110 can be configured to capture and retain particulates in the gas by impaction, interception, and / or diffusion mechanisms. Capturing and retaining particulates can help improve gas quality and, in some cases, mitigate potential undesirable consequences associated with exposing people and equipment to particulates.

[0023]

[0049] By way of example, the porous filter substrate 110 can be formed of a paper material (e.g., TYVEK®), a woven fabric, a nonwoven fabric, a fibrous material, an elastomer, a flexible material, a non-flexible material, and / or a porous film. More generally, the porous filter substrate 110 can include one or more materials defining a plurality of pores between the first surface 112 and the second surface 114, the size of the pores can affect the flow rate of gas through the porous filter substrate 110 and the extent to which the porous filter substrate 110 captures particulates. For example, relatively large pores can help increase the flow rate of gas through the porous filter substrate 110, while relatively small pores can help capture particulates of a type having a relatively fine particle size.

[0024]

[0050] In one example, the pores of the porous filter substrate 110 can have an average pore size of about 0.5 microns to about 100 microns. In another example, the pores of the porous filter substrate 110 can have an average pore size of about 0.5 microns to about 5.0 microns. In yet another example, the pores of the porous filter substrate 110 can have an average pore size of about 1.0 microns to about 2.5 microns. However, in other examples, the pores of the porous filter substrate 110 can have an average pore size of less than 0.05 microns or greater than 3.0 microns. The average pore size of the porous filter substrate 110 can be determined by the particle size of the particulates intended to be filtered, and similarly, one or more porous filters 110 of different pore sizes can be used to filter different particle sizes.

[0025]

[0051] In one example, the porous filter substrate 110 can have a plurality of accordion-fold pleats including a plurality of panels and a plurality of fold lines between each one of the plurality of panels. This can help increase the surface area of ​​the porous filter substrate 110 and therefore improve filtration efficiency compared to a non-pleated porous filter substrate 110. However, in other examples, the porous filter substrate 110 can be non-pleated. In some cases, a non-pleated shape can help reduce manufacturing costs in a relatively small space (e.g., by reducing the depth of the porous filter substrate 110 compared to a pleated porous filter substrate 110) and / or facilitate disposal of the porous filter substrate 110.

[0026]

[0052] The physical characteristics of the porous filter substrate 110 can be selected based on one or more factors, such as, for example, (i) the type of gas to be filtered, (ii) the type of particles that the porous filter substrate 110 is configured to capture and retain while passing the gas through the porous filter substrate 110, and / or (iii) the environment in which the particulate filter 100 is placed. For example, the porosity (i.e., the percentage of open space in the volume of the porous filter substrate 110), geometry, and / or material type of the porous filter substrate 110 can achieve at least a threshold performance efficiency of the particulate filter 100 based on these factors.

[0027]

[0053] Also, the particulate filter 100 can be deployed in an environment where gas flows through the porous filter substrate 110 as a pressurized gas (e.g., at a pressure higher than ambient pressure) and / or a non-pressurized gas (e.g., at atmospheric pressure). The physical properties of the porous filter substrate 110 can additionally or alternatively be selected based on the expected pressure of the gas flowing through the porous filter substrate 110. For example, the porous filter substrate 110 can be configured to have a relatively low porosity when the gas is pressurized, while the porous filter substrate 110 can be configured to have a relatively large porosity when the gas is not pressurized (e.g., the first porous filter substrate 110 can have a first porosity in a first environment where the gas flows at a first pressure, and the second porous filter substrate 110 can have a second porosity in a second environment where the gas flows at a second pressure, where the first pressure is less than the second pressure and the first porosity is greater than the second porosity).

[0028]

[0054] The particulate filter 100 can also include a frame 116 coupled to and supporting the porous filter substrate 110. In one example, the frame 116 can define apertures, and the porous filter substrate 110 can be coupled to the frame 116 such that the porous filter substrate 110 is disposed within the apertures. This can allow gas to flow through the frame 116 and the porous filter substrate 110. In an example, the frame 116 can be configured such that the apertures defined by the frame 116 have a rectangular, square, circular, elliptical, triangular, polygonal, and / or non-polygonal shape.

[0029]

[0055] In other examples, the particulate filter 100 can omit the frame 116. For example, the particulate filter 100 can omit the frame 116 in embodiments in which the porous filter substrate 110 is free-standing. As an example, the porous filter substrate 110 can be made from a material having a rigidity that allows the porous filter substrate 110 to maintain a predetermined shape under expected operating conditions such that the porous filter substrate 110 is free-standing. In embodiments in which the porous filter substrate 110 is free-standing, the porous filter substrate 110 can have a pleated and / or non-pleated configuration as described above.

[0030]

[0056] By way of example, the frame 116 can be coupled to the porous filter substrate 110 by welding, adhesives, non-adhesive bonding, snap-fit ​​retention features, friction couplings, and / or multiple hook-and-loop fasteners (such as VELCRO®). In some implementations, the frame 116 can be configured to form a seal at the interface between the frame 116 and the porous filter substrate 110. This can help reduce (or prevent) gas from flowing around the porous filter substrate 110 instead of through it. As an example, the frame 116 includes a gasket 118 for sealing the interface between the frame 116 and the porous filter substrate 110 of FIG. 1.

[0031]

[0057] In some examples, the frame 116 can have a suitable rigidity to maintain the shape of the porous filter substrate 110 and / or to hold the porous filter substrate 110 in a fixed position relative to structures in the environment in which the particulate filter 100 is deployed. This can be beneficial, for example, in implementations in which the porous filter substrate 110 is made from a relatively flexible material. However, in other examples, the particulate filter 100 can omit the frame 116 and the particulate filter 100 can be freestanding.

[0032]

[0058] During operation, particulates may accumulate on the first surface 112 and / or the second surface 114 of the porous filter substrate 110. As described above, particulates accumulated on the porous filter substrate 110 may reduce the efficiency of the particulate filter 100, and therefore it may be desirable to clean the porous filter substrate 110 to remove the particulates. In an example, the particulate filter 100 may remove particulates from the porous filter substrate 110 by generating an electric field on the first surface 112 and / or the second surface of the porous filter substrate 110. In particular, the electric field may be configured to repel and / or move particulates from the porous filter substrate 110 using at least one force selected from electrostatic force, electrodynamic force, and dielectrophoretic force.

[0033]

[0059] As shown in FIG. 1, the particulate filter 100 also includes a plurality of conductors 120 coupled to the porous filter substrate 110 and a plurality of input nodes 122 in signal communication with the conductors 120. The input nodes 122 are configured to receive a voltage signal from an input signal source 124. By way of example, the input nodes 122 can include at least one electrical connector selected from the group including a conductive fastener, a mechanical clamp, a twist cap, a crimp sleeve connector, and a pin connector. The input nodes 122 can further include an electrical insulating material arranged to insulate the conductors 120 from each other and mitigate shorts between the conductors 120.

[0034]

[0060] The type of input node 122 selected for the particulate filter 100 may be based on the environment and / or situation in which the particulate filter 100 is used. For example, the type of input node 122 may be selected based on at least one factor selected from the group of factors consisting of the mechanical strength of the input node 122, the weight of the input node 122, the size of the input node 122, and the electrical insulation characteristics of the input node 122. In some environments, it may be beneficial to select a type of input node 122 that has a suitable mechanical strength to resist separation between the conductor 120 and the input signal source 124, a suitable weight to meet the weight limit considerations of the environment and / or situation in which the particulate filter 100 is used (e.g., spacecraft and / or aircraft), a suitable size to meet the size limit considerations of the environment and / or situation in which the particulate filter 100 is used, and / or electrical insulation characteristics to mitigate short circuits between the conductors 120.

[0035]

[0061] In some implementations, the input node 122 may be a stand-alone structure. In alternative implementations, the input node 122 may be part of the frame 116. For example, in one embodiment, the input node 122 may be integrally formed with the frame 116 by a three-dimensional printing manufacturing method. Integrating the input node 122 with the frame 116 may help reduce the size and / or weight of the particulate filter 100, for example, as compared to a particulate filter 100 in which the input node 122 is separated from the frame 116.

[0036]

[0062] As described in more detail below, the input signal source 124 can generate a voltage signal, and the input node 122 can include electrodes for receiving the voltage signal and transmitting the voltage signal to the conductor 120, which can use the voltage signal to emit an electric field for manipulating particulates on and / or adjacent to the porous filter substrate 110.

[0037]

[0063] In general, the conductors 120 are configured to generate an electric field on at least one of the first surface 112 or the second surface 114 of the porous filter substrate 110 in response to an input node 122 receiving a voltage signal from an input signal source 124. In some examples, the conductors 120 can be coupled to the first surface 112 of the porous filter substrate 110 and the second surface 114 of the porous filter substrate 110. In this arrangement, the conductors 120 can provide an electric field in a manner that can help clean both sides of the porous filter substrate 110 where particulates may accumulate while filtering gas. However, in other examples, the conductors 120 can be coupled only to the first surface 112, or the conductors 120 can be coupled only to the second surface 114. This can be useful in implementations where personnel may come into contact with one of the first surface 112 or the second surface 114 with the conductors 120 omitted.

[0038]

[0064] Within examples, the conductor 120 can be bonded to the porous filter substrate by weaving, screen printing, and / or stamping the conductor 120 onto the first surface 112 and / or the second surface 114 of the porous filter substrate 110. For example, in one embodiment, the conductor 120 can include a plurality of conductive fibers (e.g., carbon nanotube fibers and / or graphite fibers) woven into the porous filter substrate 110. The conductive fibers can be made from a conductive material that (i) is resilient to fatigue so that the conductive fibers can repeatedly change shape without breaking, and (ii) has a tensile strength that resists tearing. This can be beneficial in implementations where the porous filter substrate 110 is a woven and / or fibrous material. This can additionally or alternatively be beneficial in implementations where the porous filter substrate 110 is likely to experience changes in shape. In another embodiment, for example, the conductor 120 can include a conductive material (e.g., a metal and / or a conductive polymer) on at least one of the first surface 112 of the porous filter substrate 110 or the second surface 114 of the porous filter substrate 110. This may be beneficial in implementations where the porous filter substrate 110 is a non-woven and / or non-fibrous material. This may additionally or alternatively be beneficial in implementations where the porous filter substrate 110 is less likely to experience changes in shape.

[0039]

[0065] In general, the conductors 120 are approximately parallel to one another along the porous filter substrate 110. As described in more detail below, this can help generate an electric field that can repel and / or displace particulates from the porous filter substrate 110. The term "approximately parallel" means that the conductors 120 are parallel despite deviations or variations due to manufacturing tolerances, measurement errors, measurement accuracy limitations, and other factors that may arise due to practical constraints in manufacturing and / or measuring physical devices.

[0040]

[0066] The position of the conductors 120 on the porous filter substrate 110 and / or the spacing between the conductors 120 can also affect the electric field generated by the conductors 120 to repel and / or move particulates from the porous filter substrate 110. Thus, the position and / or spacing of the conductors 120 on the porous filter substrate 110 can be based on the type and / or size of the particulates to be repelled and / or moved by the electric field. The positioning and / or spacing of the conductors 120 on the porous filter substrate 110 can additionally or alternatively be based on the shape and / or porosity of the porous filter substrate 110. FIGS. 2-7D show various arrangements of the conductors 120 on the porous filter substrate 110, according to some examples. In one example, the conductors 120 can be separated from each other by about 1 millimeter (mm) to about 2 mm. In another example, the conductors 120 can be separated from each other by about 0.3 mm to about 4.0 mm.

[0041]

[0067] The input signal source 124 may be an alternating current (AC) voltage source and / or a direct current (DC) voltage source. By way of example, the input signal source 124 may include a battery co-located with the particulate filter 100 and / or an external power source (e.g., an electrical grid, a battery, and / or a renewable energy power generation system such as a wind power generation system, a hydroelectric power generation system, a solar power generation system, and / or a fuel cell power generation system).

[0042]

[0068] Further, in examples, the input signal source 124 can be configured to provide a single-phase AC signal and / or a multi-phase AC signal. The input signal source 124 can provide a single-phase AC signal and / or a DC signal to the conductor 120 to generate an electric field in the form of a standing wave on the first surface 112 and / or the second surface 114 of the porous filter substrate 110. Generating an electric field in the form of a standing wave can help remove and repel particulates from the first surface 112 and / or the second surface 114 of the porous filter substrate 110 (e.g., by breaking adhesive or cohesive forces between the particulates and the porous filter substrate 110, e.g., by electrostatic or van der Waals forces). This can therefore help remove particulates that have accumulated on the porous filter substrate 110 (i.e., clean the porous filter substrate 110) and / or inhibit other particulates from accumulating on the porous filter substrate 110 while the standing wave of the electric field is active.

[0043]

[0069] The input signal source 124 may additionally or alternatively provide a multi-phase AC signal such that the electric field generated by the conductors 120 forms a traveling wave along the first surface 112 and / or the second surface 114. Specifically, the conductors 120 may extend in a first direction along the porous filter substrate 110, and the traveling wave may travel along the first surface 112 and / or the second surface 114 in a second direction transverse to the first direction. In this manner, the traveling wave may repel particulates from the porous filter substrate 110 (e.g., by breaking adhesive or cohesive forces between the particulates and the porous filter substrate 110, e.g., by electrostatic or van der Waals forces) and move the particulates along the porous filter substrate 110.

[0044]

[0070] As shown in FIG. 1, the particulate filter 100 can include a particulate collection receptacle 126 around the porous filter substrate 110. The particulate collection receptacle 126 can be configured to collect particulates removed from the porous filter substrate 110 by the electric field. For example, the particulate collection receptacle 126 can be positioned along the path of the particulates when the traveling wave of the electric field moves the particulates in the second direction. In this manner, the electric field generated by the conductor 120 can separate the particulates from the porous filter substrate 110 and move the particulates to the particulate collection receptacle 126.

[0045]

[0071] In some examples, the particulate collection receptacle 126 can be removably coupled to the porous filter substrate 110 and / or the frame 116 of the particulate filter 100. This can facilitate quick and efficient cleaning of the particulate filter 100 by disconnecting the particulate collection receptacle 126 to clean particulates from the particulate collection receptacle 126 and then reconnecting the particulate collection receptacle 126.

[0046]

[0072] In other examples, the particulate collection receptacle 126 can be fixedly coupled to the porous filter substrate 110 and / or the frame 116. In such examples, the particulate collection receptacle 126 can still improve cleaning efficiency, at least because the particulate collection receptacle 126 can help concentrate particulates in a central location that can be more easily and quickly cleaned than the porous filter substrate 110.

[0047]

[0073] As described above, the conductor 120, the input node 122, and / or the input signal source 124 can operate to generate an electric field such that standing and / or traveling waves are formed on the first surface 112 and / or the second surface 114 of the porous filter substrate 110. Thus, the input signal source 124 can be configured to generate a voltage signal such that the electric field forms a standing wave on at least one of the first surface 112 or the second surface 114. Additionally or alternatively, the input signal source 124 can be configured to generate a voltage signal such that the electric field forms a traveling wave, which travels along at least one of the first surface 112 or the second surface 114 in a second direction transverse to the first direction of the conductor 120.

[0048]

[0074] In FIG. 1, the operation of the input signal source 124 can be controlled by a controller 128 that communicates with the input signal source 124. In an example, the controller 128 can be implemented using hardware, software, and / or firmware. For example, the controller 128 can include one or more processors 130 and a non-transitory computer-readable medium (e.g., volatile and / or non-volatile memory 132) that stores machine language instructions or other executable instructions. The instructions, when executed by the one or more processors 130, can cause the components of the particulate filter 100 (e.g., the input signal source 124) to perform various operations described herein. Thus, the controller 128 can also receive data and store the data in memory.

[0049]

[0075] The input signal source 124 can provide a plurality of voltage levels for the voltage signal, and the controller 128 can be configured to select a voltage level for the voltage signal from among the plurality of voltage levels. In one example, the input signal source 124 can provide a voltage signal at a voltage level between about 200 volts and about 1,000 volts based on a control signal from the controller 128. In another example, the input signal source 124 can provide a voltage signal at a voltage level between about 350 volts and about 1,200 volts based on a control signal from the controller 128.

[0050]

[0076] In an example, the controller 128 can select a voltage level and / or a waveform of the voltage signal from among multiple voltage levels and / or multiple waveforms based on the type of particulate, the size of the particulate, the mass of the particulate, and / or the atmospheric conditions (e.g., gravity, temperature, and / or humidity) of the environment in which the particulate filter 100 is located. For example, moon dust (which can degrade space suits, degrade spacecraft systems, cause mechanical problems, block visibility, adversely affect instrument readings, and / or have health effects when inhaled) can be difficult to remove from conventional filters due to, for example, (1) moon dust being electrically charged by solar wind and ultraviolet light due to the lack of an atmosphere, (2) moon dust having irregularly shaped abrasive particles that can clog the pores of the porous filter substrate, and / or (3) moon dust having a relatively small particle size. In one example, to repel particulates having a size between about 5 microns and about 400 microns at lunar conditions using conductors 120 having a thickness between about 0.5 microns and about 400 microns and an inter-conductor spacing of between about 0.3 mm and about 4 mm, controller 128 can cause input signal source 124 to provide a voltage signal (i) at a voltage between about 500 volts and about 2,000 volts, (ii) at a frequency between about 5 Hertz (Hz) and about 200 Hz, and (iii) as a single-phase or polyphase signal. These parameter values ​​can be increased by about three to about five times for terrestrial applications to account for the effects of gravity, humidity, and other atmospheric conditions.

[0051]

[0077] As another example, in one embodiment, the particulate filter 100 can be configured to repel lunar dust and / or Martian dust having a size between about 10 microns and about 75 microns using an electric field generated by the conductor 120. In this exemplary embodiment, the conductor 120 can be a carbon nanotube fiber having a thickness of about 180 microns to about 200 microns and can be separated by about 1 mm to about 2 mm. Furthermore, in this exemplary implementation, the input signal source 124 can provide a voltage signal at a voltage level between about 350 volts and about 1,200 volts based on a control signal from the controller 128 to effectively repel lunar dust and / or Martian dust from the porous filter substrate 110.

[0052]

[0078] The voltage level and / or the waveform of the voltage signal may additionally or alternatively be based on the operating mode of the particulate filter 100. For example, as described above, the input signal source 124 may be operated in a first operating mode that causes the conductor 120 to generate an electric field in the form of a standing wave, and / or the input signal source 124 may be operated in a second operating mode that causes the conductor 120 to generate an electric field in the form of a traveling wave. In an example, when the input signal source 124 operates in the first operating mode, the voltage signal may have a first voltage level and / or a first waveform, and when the input signal source operates in the second operating mode, the voltage signal may have a second voltage level and / or a second waveform. The first voltage level may be different from the second voltage level, and / or the first waveform may be different from the second waveform.

[0053]

[0079] In one embodiment, the controller 128 can have the input signal source 124 initially provide a voltage signal such that the electric field forms a standing wave to separate the particulates from the porous filter substrate 110. While the electric field is applied in the form of a standing wave, the particulates can be suspended on the first surface 112 and / or the second surface 114 of the porous filter substrate 110. After forming the standing wave, the controller 128 can vary the voltage signal to the input signal source 124 such that the electric field forms a traveling wave that moves the suspended particles in a second direction away from the porous filter substrate 110 (e.g., toward the particulate collection receptacle 126).

[0054]

[0080] Additionally or alternatively, the controller 128 can operate the input signal source 124 in a continuous mode and / or a pulsed mode. For example, when operating in a continuous mode, the input signal source 124 can provide a voltage signal continuously such that the electric field generated by the conductor 120 forms a barrier that prevents particulates from reaching the porous filter substrate 110. This can thus help reduce the amount of particulates that accumulate on the porous filter substrate 110.

[0055]

[0081] When operating in a pulsed mode, the input signal source 124 can provide a voltage signal in a pulsed manner, such as, for example, a pulse having a duration of about 30 seconds to about 60 seconds, which can help dislodge and repel particulates that have previously accumulated on the porous filter substrate 110.

[0056]

[0082] 1, the particulate filter 100 can also include a sensor 134 that can measure the amount of particles (e.g., dust) on the porous filter substrate 110. By way of example, the sensor 134 can include one or more capacitive sensors and / or one or more optical sensors. The sensor 134 can be disposed on, embedded within, and / or adjacent to the first surface 112 and / or the second surface 114 of the porous filter substrate 110.

[0057]

[0083] The controller 128 can be in communication with the sensor 134 and the input signal source 124. In one example, the controller 128 can be configured to automatically perform cleaning of the porous filter substrate 110 using the sensor signal. For example, the controller 128 can (i) receive a sensor signal from the sensor 134 indicative of an amount of particulates (e.g., dust) on the porous filter substrate 110, (ii) determine that more than a threshold amount of particulates have accumulated on the porous filter substrate 110 based on the amount of particulates (e.g., dust) indicated by the sensor signal, and (iii) in response to determining that more than a threshold amount of particulates have accumulated on the porous filter substrate 110, cause the input signal source 124 to provide voltage signals to the plurality of input nodes 122 to generate an electric field and remove particulates from the porous filter substrate 110. Automatically cleaning the porous filter substrate 110 can improve operational efficiency by cleaning the porous filter substrate 110 more efficiently, quickly, and / or frequently, when such cleaning is required.

[0058]

[0084] The controller 128 may additionally or alternatively (i) receive a sensor signal from the sensor 134 indicative of an amount of particulates (e.g., dust) on the porous filter substrate 110, (ii) determine a value of an electrical parameter of the voltage signal based on the amount of particulates (e.g., dust) indicated by the sensor signal, and (iii) cause the input signal source 124 to provide a voltage signal having the electrical parameter with the value to the plurality of input nodes 122. For example, the electrical parameter may relate to at least one of a voltage level or a waveform (e.g., frequency, phase, and / or pulse width) of the voltage signal. In one example, the controller 128 may repeatedly perform the steps of receiving a sensor signal from the sensor 134, determining an electrical parameter, and providing the input signal source 124 with the electrical parameter with the value for the voltage signal. This may help to change the voltage level and / or waveform (e.g., frequency, phase, and / or pulse width) in response to a change in the amount of particulates on the porous filter substrate 110.

[0059]

[0085] In one embodiment where the electrical parameter includes a voltage value, the voltage value determined by the controller 128 may increase as the amount of particles measured by the sensor 134 increases (i.e., a relatively large voltage may be applied when the sensor 134 measures a relatively large amount of particulates on the porous filter substrate 110, and a relatively low voltage may be applied when the sensor 134 measures a relatively small amount of particulates on the porous filter substrate 110). For example, in one example, the controller 128 may compare the amount of particulates measured by the sensor 134 to a threshold value. In response to the controller 128 determining, based on the comparison, that the amount of particulates measured by the sensor 134 is greater than the threshold value, the controller 128 may cause the input signal source 124 to provide a voltage signal having a first voltage value to the plurality of input nodes 122. Meanwhile, in response to the controller 128 determining, based on the comparison, that the amount of particulates measured by the sensor 134 is less than the threshold value, the controller 128 may cause the input signal source 124 to provide a voltage signal having a second voltage value to the plurality of input nodes 122. In this example, the first voltage value may be greater than the second voltage value.

[0060]

[0086] Further, for example, when the controller 128 activates the input signal source 124 before particulates have settled on the porous filter substrate 110, the particulates can be repelled and prevented from reaching the porous filter substrate 110 by the input signal source 124 providing a voltage signal with a relatively low voltage level. On the other hand, if the particulates have already settled on the porous filter substrate 110, the particulates can be repelled from the first surface 112 and / or the second surface 114 of the porous filter substrate 110 by the input signal source 124 providing a voltage signal with a relatively high AC voltage level and / or DC voltage.

[0061]

[0087] In some examples, the controller 128 can use a look-up database (e.g., stored in memory 132) to determine electrical parameters of the voltage signal (e.g., signal waveform type, frequency, voltage, phase, etc.) to use or adjust to remove and / or repel particulates that have settled or have settled on the porous filter substrate 110 based on input data from the sensor 134. The look-up database can include values ​​based on a sensor or other source in signal communication with the controller.

[0062]

[0088] 2-7 show some implementations of the particulate filter 100 according to the example. FIG. 2 shows a particulate filter 200 including a porous filter substrate 210. In FIG. 2, the porous filter substrate 210 has a plurality of accordion-folded pleats 236 including a plurality of panels 238 and a plurality of fold lines 240 between each one of the plurality of panels 238. As described above, providing the porous filter substrate 210 with the accordion-folded pleats 236 can help increase the surface area of ​​the porous filter substrate 210 for a particular height and a particular width of the porous filter substrate 210.

[0063]

[0089] As shown in FIG. 2, the particulate filter 200 includes a plurality of conductors 220 extending across a plurality of panels 238 and a plurality of fold lines 240. This can help to remove and repel particulates from a relatively large surface area when the conductors 120 are energized, and / or help to remove and repel relatively small particulates. In FIG. 2, the conductors 220 extend in a first direction 242 from a plurality of input nodes 222 in signal communication with an input signal source 224. Although FIG. 2 shows the conductors 220 extending over a portion of the porous filter substrate 210 (e.g., the top half of the porous filter substrate 210) for ease of explanation, the conductors 220 can extend over other portions or the entire porous filter substrate 210 in other examples.

[0064]

[0090] Further, as shown in FIG. 2, the particulate filter 200 may include a frame 216 that is coupled to and supports the porous filter substrate 210. In FIG. 2, the frame 216 is rectangular in shape. However, the frame 216 may have a different shape in other examples. The frame 216 may also accommodate the input signal source 224 of FIG. 2. However, the input signal source 224 may be remotely located outside the frame 216 in other examples.

[0065]

[0091] 2, the particulate filter 200 can also include a particulate collection receptacle 226 at the periphery of the porous filter substrate 210 and configured to collect particulates removed from the porous filter substrate 210 by the electric field, as described above. In FIG. 2, the particulate collection receptacle 226 can be coupled to the frame 216.

[0066]

[0092] As described above, in some cases, the input signal source 224 can generate a voltage signal such that the electric field forms a traveling wave that travels in a second direction 244 transverse to the first direction 242 along at least one of the first surface or the second surface. As shown in FIG. 2, the particle collection receptacle 226 is disposed along a path along which the particle travels when moved in the second direction 244 by the traveling wave. The arrangement of the conductor 220 and this position of the particle collection receptacle 226 relative to the second direction 244 of the traveling wave can aid in efficient collection of the particle in the particle collection receptacle 226.

[0067]

[0093] FIG. 3 shows a particulate filter 300 including a porous filter substrate 310. In FIG. 3, the porous filter substrate 310 has a plurality of accordion-folded pleats 336 including a plurality of panels 338 and a plurality of fold lines 340 between each of the plurality of panels 338. As described above, providing the porous filter substrate 310 with the accordion-folded pleats 336 can help increase the surface area of ​​the porous filter substrate 310 for a particular height and a particular width of the porous filter substrate 310. In FIG. 3, each conductor 320 extends along a respective one of the plurality of fold lines 340. This helps to remove and repel relatively large particulates and / or helps to reduce costs in implementations where relatively small particulate loads are expected.

[0068]

[0094] 3, the particulate filter 300 can include a frame 316 coupled to and supporting the porous filter substrate 310. The frame 316 can house an input signal source 324 in signal communication with a number of input nodes 322, which are in signal communication with the conductors 320 and configured to receive voltage signals from the input signal source 324.

[0069]

[0095] In Fig. 3, the conductor 320 extends in a first direction 342. As described above, in some cases, the input signal source 324 can generate a voltage signal such that the electric field forms a traveling wave that travels in a second direction 344 transverse to the first direction 342 along at least one of the first surface or the second surface of the porous filter substrate 310. Although not shown in Fig. 3, the particulate filter 300 can include a particulate collection receptacle (e.g., particulate collection receptacle 126, 226) at the periphery of the porous filter substrate 310 (e.g., located along the path that the particulate travels when moved in the second direction 244 by the traveling wave) to help collect particulates removed and / or repelled by the particulate filter 300.

[0070]

[0096] In Figs. 2-3, the particulate filters 200, 300 include porous filter substrates 210, 310 having a plurality of accordion-folded pleats 236, 336. However, as described above, the porous filter substrate 110 can omit the accordion-folded pleats 236, 336 in other examples. For example, Figs. 4A-4B show particulate filters 400A, 400B each including a porous filter substrate 410 with the pleats omitted. In Fig. 4A, the particulate filter 400A includes a plurality of conductors 420 extending laterally across the porous filter substrate 410. In this arrangement, the conductors 420, when energized, can form concentric circles that can help remove particulates in a direction from a relatively large circle toward a relatively small circle (which can generally coincide with gravity in terrestrial implementations). The conductors 420 arranged in concentric circles can be approximately parallel to each other. In Fig. 4B, the particulate filter 400B has conductors 420 that extend longitudinally across the porous filter substrate 410. In this arrangement, the conductors 420 can be energized to remove and repel particulates laterally (i.e., transverse to the direction of the conductors 420).

[0071]

[0097] 4A-4B, the particulate filters 400A, 400B include a frame 416 that is coupled to and supports the porous filter substrate 410. In these examples, the frame 416 is coupled to a single end of the porous filter substrate 410 and serves to define an opening at the end of the porous filter substrate 410 through which gas can flow. However, as noted above, the particulate filters 440A, 440B may omit the frame 416 in other examples (e.g., in embodiments in which the porous filter substrate 410 is freestanding).

[0072]

[0098] Now referring to FIG. 5, a cross-sectional view of a particulate filter 500 is shown according to another example. In FIG. 5, the particulate filter 500 includes a porous filter substrate 510 and a frame 516 coupled to and supporting the porous filter substrate 510. Further, in FIG. 5, the porous filter substrate 510 includes a plurality of filter media 546A-546F arranged in parallel planes between a first surface 512 of the porous filter substrate 510 and a second surface 514 of the porous filter substrate 510. The filter media 546A-546F can be formed from the same or similar materials as those described above with respect to the porous filter substrate 110. For example, the filter media 546A-546F can be formed from a paper material (e.g., TYVEK®), a woven fabric, a nonwoven fabric, a fibrous material, an elastomer, a flexible material, a non-flexible material, and / or a porous film. More generally, the filter media 546A-546F can include one or more materials that define a plurality of pores between the first surface 512 and the second surface 514, and the size of the pores can affect the flow rate of gas through the porous filter substrate 510 and the degree to which the porous filter substrate 510 captures particles. Providing a plurality of filter media 546A-546F between the first surface 512 and the second surface 514 can help define a tortuous path for gas and particulates to flow through the porous filter substrate 510, which helps to improve the effectiveness of filtration.

[0073]

[0099] In some implementations, the filter media 546A-546F can all be formed from a common type of material. This can be beneficial, for example, in implementations where the porous filter substrate 510 is configured to capture a particular type of particulate and / or multiple types of particulates having relatively similar particle sizes. In other embodiments, at least one of the filter media 546A-546F can be formed from a material that is different from the material from which at least another one of the filter media 546A-546F is formed. This can be beneficial, for example, in implementations where the porous filter substrate 510 is configured to capture multiple different types of particulates having multiple different particle sizes.

[0074]

[0100] As shown in FIG. 5, the particulate filter 500 also includes a plurality of conductors 520 coupled to the porous filter substrate 510 in a manner similar to that described above with respect to the conductors 120 coupled to the porous filter substrate 110 (e.g., by weaving, screen printing, and / or stamping the conductors 520 onto the porous filter substrate 510). In particular, the plurality of conductors 520 are coupled to the filter media 546A-546F of the porous filter substrate 510. For example, in FIG. 5, the plurality of conductors 520 are coupled to the filter media 546A of the plurality of filter media 546 that defines the first surface 512 of the porous filter substrate 510. Also, in FIG. 5, the plurality of conductors can be coupled to the filter media 546F that defines the second surface 514 of the porous filter substrate 510 and / or the filter media 546C that is located between the first surface 512 and the second surface 514 of the porous filter substrate 510.

[0075]

[0101] 5, the conductor 520 can be coupled to different ones of the filter media 546A-546F in other examples. For example, the conductor 520 can be coupled to any combination or permutation of the filter media 546A-546F based on one or more factors, such as, for example, the type of particulates, the filter media 546A-546F configured to capture a quantity of the filter media 546A-546F, and / or the relative position of the filter media 546A-546F within the porous filter substrate 510. Additionally, while the porous filter substrate 510 includes six filter media 546A-546F in FIG. 5, the porous filter substrate 510 can include fewer or greater amounts of the filter media 546A-546F in other examples. For example, the porous filter substrate 510 can include a smaller amount of filter media 546A-546F to provide a relatively greater amount of airflow, or the porous filter substrate 510 can include a larger amount of filter media 546A-546F to increase the filtering capacity of the porous filter substrate 510 (i.e., to capture a greater amount of particulates).

[0076]

[0102] Referring now to Fig. 6, according to another example, a particulate filter 600 is shown. In Fig. 6, the particulate filter 600 includes a porous filter substrate 310 having a plurality of panels 638 and a plurality of accordion-folded pleats 636 including a plurality of fold lines 640 between respective ones of the plurality of panels 638. In Fig. 6, each conductor 620 extends along a respective one of the plurality of fold lines 640, as described above with respect to Fig. 3.

[0077]

[0103] The particulate filter 600 may also include a frame 616 coupled to and supporting the porous filter substrate 610. The frame 616 may house an input signal source 624 in signal communication with a number of input nodes 622, which are in signal communication with the conductors 620 and configured to receive voltage signals from the input signal source 624.

[0078]

[0104] In FIG. 6, the particulate filter 600 also includes an actuator 648 (e.g., an electromechanical actuator, a pneumatic actuator, and / or a hydraulic actuator) coupled to the accordion fold pleats 636 and configured to adjust the shape of the porous filter substrate 610 from a first shape to a second shape. For example, the actuator 648 can be operated to move one or more of the accordion fold pleats 636 relative to at least one other one of the accordion fold pleats 636 (and / or the frame 616). For example, in FIG. 6, the actuator 648 moves the accordion fold pleats 636 to open and expose a region 650 between a pair of adjacent accordion fold pleats 636 (i.e., the porous filter substrate 610 is in the second shape in FIG. 6). While the accordion fold pleats 636 are so opened, the conductors 620 can generate an electric field to repel and / or remove particulates. Opening the accordion fold pleats 636 using the actuators 648 can help improve cleaning efficiency.

[0079]

[0105] In some implementations, the actuator 648 can repeatedly open and close each pair of adjacent accordion fold pleats 636 to apply an electric field to perform a cleaning cycle. In some examples, the actuator 648 can also be in communication with the controller 128 shown in FIG. 1, which can be operable to control the operation of the actuator 648. For example, the controller 128 can be configured to operate the actuator 648 to open the accordion fold pleats 636, and while the accordion fold pleats 636 are open, the controller 128 can cause the input signal source 624 to provide a voltage signal to the conductor 620, as described above.

[0080]

[0106] As described above, the conductors 120 can be coupled to the first surface 112 and / or the second surface 114 of the porous filter substrate 110 by weaving, screen printing, and / or stamping. By way of example, Figures 7A-7D show cross-sectional views of a number of conductors 720A-720D coupled to example porous filter substrates 710A-710D, respectively.

[0081]

[0107] In FIG. 7A, the conductor 720A includes a plurality of conductive fibers woven into the porous filter substrate 710A. In particular, the conductor 720A is woven into the porous filter substrate 710A such that the conductor 720A extends to (and / or through) the first surface 712A and the second surface 714A of the porous filter substrate 710A. Thus, the conductor 720A can generate an electric field on both the first surface 712A and the second surface 714A of the porous filter substrate 710A. This can help repel and / or remove particulates on both the first surface 712A and the second surface 714A of the porous filter substrate 710A.

[0082]

[0108] In Figure 7B, the conductor 720B also includes a plurality of conductive fibers woven into the porous filter substrate 710B. However, in Figure 7B, the conductor 720B extends to (and / or through) the first surface 712B, but the conductor 720B does not extend to the second surface 714B of the porous filter substrate 710B. Thus, the conductor 720B can generate an electric field at the first surface 712B, but not at the second surface 714B of the porous filter substrate 710B. This can help repel and / or remove particles on the first surface 712B.

[0083]

[0109] In Figures 7A-7B, the conductors 720A, 720B comprise conductive fibers woven into the porous filter substrates 710A, 710B. However, as noted above, the conductors may additionally or alternatively comprise conductive material printed on at least one of the first surface of the porous filter substrate or the second surface of the porous filter substrate. In Figure 7C, the conductors 720C comprise conductive material printed on the first surface 712C of the porous filter substrate 710C, but not on the second surface 714C of the porous filter substrate 710C. Thus, the conductors 720C may generate an electric field on the first surface 712C, but not on the second surface 714C of the porous filter substrate 710C. This may help repel and / or remove particulates on the first surface 712C.

[0084]

[0110] In Figure 7D, the conductor 720D includes a conductive material printed on the first surface 712D and the second surface 714D. Thus, the conductor 720D can generate an electric field on both the first surface 712D and the second surface 714D of the porous filter substrate 710D. This can help repel and / or remove particulates on both the first surface 712D and the second surface 714D of the porous filter substrate 710D.

[0085]

[0111] Referring now to FIG. 8, a simplified block diagram of a filter system 852 is shown according to an example. As shown in FIG. 8, the filter system 852 includes a particulate filter 800 and an electromagnetic field generator 854. The particulate filter 800 may be similar or identical to the particulate filters 100, 200, 300, 400, 500, 600 shown and described above with respect to FIGS. 1-6. For example, the particulate filter 800 may include a porous filter substrate 810 including a first surface 812 and a second surface 814. As described above, the porous filter substrate 810 is configured to filter gas flowing through the porous filter substrate 810 between the first surface 812 and the second surface 814.

[0086]

[0112] The particulate filter 800 may also include a plurality of conductors 820 coupled to the porous filter substrate 810. The conductors 820 may be generally parallel to one another along the porous filter substrate 810. In addition, the particulate filter 800 may include a plurality of input nodes 822 in signal communication with the plurality of conductors 820 and configured to receive a voltage signal from an input signal source 824. The plurality of conductors 820 are configured to generate an electric field on at least one of the first surface 812 or the second surface 814 of the porous filter substrate 810 in response to the plurality of input nodes 822 receiving a voltage signal from the input signal source 824. As described above, when the electric field is generated, the electric field may repel and remove particulates accumulated on the porous filter substrate 810 and / or repel the particulates to prevent the particulates from accumulating on the porous filter substrate 810.

[0087]

[0113] In an example, the conductors 820 can be bonded onto at least one surface selected from the first surface 812 of the porous filter substrate 810 and the second surface 814 of the porous filter substrate 810. For example, as described above, the conductors 820 can be bonded to the first surface 812 and / or the second surface 814 of the porous filter substrate 810 by weaving, screen printing, and / or stamping, as described above and shown, for example, in Figures 7A-7D. Thus, in one embodiment, the conductors 820 can include a plurality of conductive fibers woven into the porous filter substrate 810.

[0088]

[0114] The particulate filter 800 may further include any other features of the particulate filters 100, 200, 300, 400, 500, 600 described above and / or shown in Figures 1-7. For example, the particulate filter 800 may include a frame 816 in some implementations to help provide structural rigidity around the particulate filter 800, or the particulate filter 800 may omit the frame 816 in other embodiments in which the porous filter substrate 810 is freestanding. Additionally, for example, the particulate filter 800 may include a gasket 818 for sealing the interface between the frame 816 and the porous filter substrate 810, as described above.

[0089]

[0115] In some examples, the particulate filter 800 may also include an input signal source 824, as described above. Thus, as described above, the input signal source 824 may be operated in a first operating mode in which the conductor 820 generates an electric field in the form of a standing wave, and / or the input signal source 824 may be operated in a second operating mode in which the conductor 820 generates an electric field in the form of a traveling wave. Thus, in the first operating mode, the input signal source 824 may generate a voltage signal such that the electric field forms a standing wave on at least one of the first surface 812 or the second surface 814 of the porous filter substrate 810. Meanwhile, in the second operating mode, the input signal source 824 may generate a voltage signal such that the electric field forms a traveling wave. More specifically, as described above, the conductor 820 can extend in a first direction along the porous filter substrate 810, and the input signal source 824 can generate a voltage signal such that the electric field forms a traveling wave that travels in a second direction transverse to the first direction along at least one of the first surface 812 or the second surface 814.

[0090]

[0116] In FIG. 8, the operation of the input signal source 824 can be controlled by a controller 828 in communication with the input signal source 824. In an example, the controller 828 can be implemented using hardware, software, and / or firmware. For example, the controller 828 can include one or more processors 830 and a non-transitory computer-readable medium (e.g., volatile and / or non-volatile memory 832) that stores machine language instructions or other executable instructions. The instructions, when executed by the one or more processors 830, can cause the components of the particulate filter 800 (e.g., the input signal source 824) to perform various operations described herein. Thus, the controller 828 can also receive data and store the data in memory.

[0091]

[0117] In some examples, the particulate filter 800 may additionally or alternatively include a particulate collection receptacle 826 at the periphery of the porous filter substrate 810, configured to collect particulates removed from the porous filter substrate 810 by the electric field, as described above. In some implementations, the particulate collection receptacle 826 may be positioned along the path of the particulates when the traveling wave of the electric field moves the particulates in the second direction. In this manner, the electric field generated by the conductor 820 may separate the particulates from the porous filter substrate 810 and move the particulates to the particulate collection receptacle 826. As described above, the particulate collection receptacle 826 may help to increase cleaning efficiency, at least because the particulate collection receptacle 826 may help to concentrate the particulates in a central location that can be cleaned more easily and quickly than the porous filter substrate 810.

[0092]

[0118] Also, in some examples, the particulate filter 800 can include an actuator 848 operable to adjust the shape of the porous filter substrate 810 as described above with respect to FIG. 6. For example, the actuator 848 can be operated to move one or more accordion-folded pleats (e.g., accordion-folded pleats 636 in FIG. 6) of the porous filter substrate 810 relative to at least one other accordion-folded pleat (and / or frame 816). As described above, while the accordion-folded pleats are thus opened, the conductor 820 can generate an electric field to repel and / or remove particulates. Opening the accordion-folded pleats using the actuator 848 can help improve cleaning efficiency.

[0093]

[0119] In some examples, the particulate filter 800 can include a sensor 834 that can measure the amount of particulates (e.g., dust) on the porous filter substrate 810 as described above. Furthermore, the sensor 834 can communicate with the controller 828, and the controller 828 can use the sensor signal received from the sensor 834 based on (i) causing the generation of an electric field on the conductor 820 and / or (ii) determining the electrical parameters of the voltage signal for generating the electric field on the conductor 820 as described above.

[0094]

[0120] In Fig. 8, the electromagnetic field generator 854 is operable to generate an electromagnetic field 856 configured to charge particulates in the gas before the gas flows through the porous filter substrate 810. For example, in Fig. 8, the electromagnetic field generator 854 is operable to generate the electromagnetic field 856 in a space 858 upstream of the particulate filter 800 along the gas flow path (e.g., the electromagnetic field generator 854 can be disposed upstream of the particulate filter 800 along the gas flow path). By charging the particulates in the gas before the gas flows through the porous filter substrate 810, the electric field generated by the conductor 820 of the particulate filter 800 can be more effectively used to help repel and remove particulates accumulated on the porous filter substrate 810.

[0095]

[0121] In one example, the electromagnetic field generator 854 can include an EMF power source 860 and an electromagnetic radiation element 862. The EMF power source 860 can provide power to the electromagnetic radiation element 862, which can use the power to radiate an electromagnetic field 856 in a space 858 upstream of the particulate filter 800. By way of example, the electromagnetic radiation element 862 can include at least one element selected from an antenna, a coil, and a mesh structure formed from a conductive material.

[0096]

[0122] In some implementations, the electromagnetic field generator 854 can include an EMF controller 864. In such implementations, the EMF controller 864 can operatively control the EMF power source 860 and / or the electromagnetic radiation element 862 to set and / or adjust the frequency of the electromagnetic field 856, the intensity of the electromagnetic field 856, and / or the radiation pattern in space of the electromagnetic field 856. In one example, the electromagnetic field generator 854 can generate an electromagnetic field at a frequency between about 1 Hertz (Hz) and about 300 Hz.

[0097]

[0123] 9A shows a side view of a filter system 952 according to an exemplary implementation of the filter system 852 shown in FIG. 8. As shown in FIG. 9A, the filter system 952 includes a particulate filter 900 and an electromagnetic field generator 954 that are substantially similar or identical to the particulate filter 800 and the electromagnetic field generator 854 described above. As shown in FIG. 9A, the electromagnetic field generator 954 is disposed upstream of the particulate filter 900 along the flow path 966 of the gas. In this configuration, the electromagnetic field generator 954 is operable to generate an electromagnetic field that charges particulates in the gas before the gas flows through the particulate filter 900.

[0098]

[0124] 9B illustrates an electromagnetic radiation element of the electromagnetic field generator 954 according to an example. As shown in FIG. 9B, the electromagnetic field generator 954 includes a mesh structure 962 offset from the first surface 912 of the particulate filter 900 by a gap 968 between the electromagnetic field generator 954 and the particulate filter 900. The mesh structure 962 includes a plurality of conductive strands 970 that define a plurality of apertures 972. The apertures 972 have a size larger than the size of the particulates in the gas. In this arrangement, an EMF power source (e.g., EMF power source 860) can power the mesh structure 962 to cause the conductive strands 970 to emit an electromagnetic field that can charge the particulates in the gas, while the apertures 972 allow the particulates in the gas to flow through the mesh structure 962 and be filtered and / or collected by the particulate filter 900.

[0099]

[0125] As described above, the mesh structure 962 can be separated from the particulate filter 900 by a gap 968. The gap 968 between the mesh structure 962 and the particulate filter 900 can help reduce interference between the electric fields generated by the conductors (e.g., conductors 120, 820) of the particulate filter 900 from the electromagnetic field generated by the electromagnetic field generator 954.

[0100]

[0126] Referring now to FIG. 10, a simplified block diagram of a filter system 1052 is shown, according to an example. As shown in FIG. 10, the filter system 1052 includes a particulate filter 1000 and a gas mover 1074. The particulate filter 1000 may be similar or identical to the particulate filters 100, 200, 300, 400, 500, 600, 800 shown and described above with respect to FIGS. 1-6 and 8-9A. For example, the particulate filter 1000 may include a porous filter substrate 1010 including a first surface 1012 and a second surface 1014. As described above, the porous filter substrate 1010 is configured to filter gas flowing through the porous filter substrate 1010 between the first surface 1012 and the second surface 1014.

[0101]

[0127] The particulate filter 1000 may also include a plurality of conductors 1020 coupled to the porous filter substrate 1010. The conductors 1020 may be generally parallel to one another along the porous filter substrate 1010. In addition, the particulate filter 1000 may include a plurality of input nodes 1022 in signal communication with the plurality of conductors 1020 and configured to receive a voltage signal from an input signal source 1024. The plurality of conductors 1020 are configured to generate an electric field on at least one of the first surface 1012 or the second surface 1014 of the porous filter substrate 1010 in response to the plurality of input nodes 1022 receiving a voltage signal from the input signal source 1024. As described above, when the electric field is generated, the electric field may repel and remove particulates accumulated on the porous filter substrate 1010 and / or repel the particulates to prevent the particulates from accumulating on the porous filter substrate 1010.

[0102]

[0128] In examples, the conductors 1020 can be bonded onto at least one surface selected from the first surface 1012 of the porous filter substrate 1010 and the second surface 1014 of the porous filter substrate 1010. For example, as described above, the conductors 1020 can be bonded to the first surface 1012 and / or the second surface 1014 of the porous filter substrate 1010 by weaving, screen printing, and / or stamping, as described above and shown, for example, in Figures 7A-7D.

[0103]

[0129] The particulate filter 1000 may further include any other features of the particulate filters 100, 200, 300, 400, 500, 600, 800, 900 described above and / or shown in Figures 1-9A. For example, the particulate filter 1000 may include a frame 1016 in some implementations to help provide structural rigidity around the particulate filter 1000, or the particulate filter 1000 may omit the frame 1016 in other embodiments in which the porous filter substrate 1010 is freestanding. Additionally, for example, the particulate filter 1000 may include a gasket 1018 for sealing the interface between the frame 1016 and the porous filter substrate 1010, as described above.

[0104]

[0130] In some examples, the particulate filter 1000 may also include an input signal source 1024, as described above. Thus, as described above, the input signal source 1024 may be operated in a first operating mode that causes the conductor 1020 to generate an electric field in the form of a standing wave, and / or the input signal source 1024 may be operated in a second operating mode that causes the conductor 1020 to generate an electric field in the form of a traveling wave. Thus, in the first operating mode, the input signal source 1024 may generate a voltage signal such that the electric field forms a standing wave on at least one of the first surface 1012 or the second surface 1014 of the porous filter substrate 1010. Meanwhile, in the second operating mode, the input signal source 1024 may generate a voltage signal such that the electric field forms a traveling wave. More specifically, as described above, the conductor 1020 can extend in a first direction along the porous filter substrate 1010, and the input signal source 1024 can generate a voltage signal such that the electric field forms a traveling wave that travels in a second direction transverse to the first direction along at least one of the first surface 1012 or the second surface 1014.

[0105]

[0131] In FIG. 10, the operation of the input signal source 1024 can be controlled by a controller 1028 in communication with the input signal source 1024. In an example, the controller 1028 can be implemented using hardware, software, and / or firmware. For example, the controller 1028 can include one or more processors 1030 and a non-transitory computer-readable medium (e.g., volatile and / or non-volatile memory 1032) that stores machine language instructions or other executable instructions. The instructions, when executed by the one or more processors 1030, can cause the components of the particulate filter 1000 (e.g., the input signal source 1024) to perform various operations described herein. Thus, the controller 1028 can also receive data and store the data in memory.

[0106]

[0132] In some examples, the particulate filter 1000 may additionally or alternatively include a particulate collection receptacle 1026 at the periphery of the porous filter substrate 1010, configured to collect particulates removed from the porous filter substrate 1010 by the electric field, as described above. In some implementations, the particulate collection receptacle 1026 may be positioned along the path of the particulates when the traveling wave of the electric field moves the particulates in the second direction. In this manner, the electric field generated by the conductor 1020 may separate the particulates from the porous filter substrate 1010 and move the particulates to the particulate collection receptacle 1026. As described above, the particulate collection receptacle 1026 may help to increase cleaning efficiency, at least because the particulate collection receptacle 1026 may help to concentrate the particulates in a central location that can be cleaned more easily and quickly than the porous filter substrate 1010.

[0107]

[0133] Also, in some examples, the particulate filter 1000 can include an actuator 1048 operable to adjust the shape of the porous filter substrate 1010 as described above with respect to FIG. 6. For example, the actuator 1048 can be operated to move one or more accordion-folded pleats (e.g., accordion-folded pleats 636 in FIG. 6) of the porous filter substrate 1010 relative to at least one other accordion-folded pleat (and / or frame 1016). As described above, while the accordion-folded pleats are thus opened, the conductor 1020 can generate an electric field to repel and / or remove particulates. Opening the accordion-folded pleats using the actuator 1048 can help improve cleaning efficiency.

[0108]

[0134] In some examples, the particulate filter 1000 can include a sensor 1034 that can measure the amount of particulates (e.g., dust) on the porous filter substrate 1010 as described above. Furthermore, as described above, the sensor 1034 can communicate with the controller 1028, and the controller 1028 can use the sensor signal received from the sensor 1034 based on (i) causing the generation of an electric field on the conductor 1020 and / or (ii) determining the electrical parameters of the voltage signal for generating the electric field on the conductor 1020.

[0109]

[0135] In Fig. 10, the gas mover 1074 is operable to generate turbulence in the gas before the gas flows through the porous filter substrate 1010. For example, in Fig. 10, the gas mover 1074 is operable to generate turbulence in the space 1058 upstream of the particulate filter 1000 along the gas flow path (e.g., the gas mover 1074 can be disposed upstream of the particulate filter 1000 along the gas flow path). Generating turbulence in the gas before the gas flows through the porous filter substrate 1010 can help to more effectively capture particulates in the porous filter substrate 1010 and / or more effectively use the electric field generator by the conductor 1020 to help repel and inhibit particulates from accumulating on the porous filter substrate 1010.

[0110]

[0136] In one example, the gas mover 1074 can include a fan oriented and positioned to blow gas (e.g., air) along the gas flow path toward the space 1058 upstream of the particulate filter 1000. The blown gas in the space 1058 can interact with the gas flowing along the flow path to generate turbulence in the gas flowing along the flow path toward the particulate filter 1000. In another example, the gas mover 1974 can additionally or alternatively include a compressor. This can be beneficial, for example, in implementations where the particulate filter 1000 is used in an air-conditioned environment.

[0111]

[0137] 11 shows a side view of a filter system 1152 according to an exemplary implementation of the filter system 1052 shown in FIG. 11, the filter system 1152 includes a particulate filter 1100 and a gas mover 1174 that are substantially similar or identical to the particulate filter 1000 and gas mover 1174 described above. As shown in FIG. 11, the gas mover 1174 is disposed upstream of the particulate filter 1100 along the gas flow path 1166. In this configuration, the gas mover 1174 is operable to direct the flow of gas into the gas flow path 1166, thereby creating turbulence in the gas before it flows through the particulate filter 1100.

[0112]

[0138] 11, the gas mover 1174 is coupled to a frame 1116 of the particulate filter 1100. This may help maintain the gas mover 1174 and the particulate filter 1100 in a fixed position and orientation relative to one another. However, in other examples, the gas mover 1174 may be coupled to a structure separate from the particulate filter 1100. This may be beneficial in implementations where the porous filter substrate 1110 of the particulate filter 1100 is freestanding and omits the frame 1116.

[0113]

[0139] 11, the gas mover 1174 is positioned relative to the particulate filter 1100 such that the gas mover 1174 can direct the flow of gas in a direction transverse to the direction of the flow path 1166 of the gas flowing through the particulate filter 1100. This can help create turbulence in the gas flowing along the flow path 1166. Notably, in FIG. 11, the gas mover 1174 is positioned to direct the flow of gas in a direction perpendicular to the direction of the flow path 1166. However, the gas mover 1174 can be positioned differently relative to the particulate filter 1100 and / or the flow path 1166 in other examples.

[0114]

[0140] 12-13, an example filter system 1252 is shown. In particular, FIG. 12 illustrates a simplified block diagram of the filter system 1252, according to an example, and FIG. 13 illustrates one implementation of the filter system 1252, according to an example.

[0115]

[0141] As shown in Figures 12-13, the filter system 1252 includes a particulate filter 1200 and a gas recirculation system 1276. The particulate filter 1200 may be similar or identical to the particulate filters 100, 200, 300, 400, 500, 600, 800, 1000 shown and described above with respect to Figures 1-6 and 8-11. For example, the particulate filter 1200 may include a porous filter substrate 1210 including a first surface 1212 and a second surface 1214. As described above, the porous filter substrate 1210 is configured to filter gas flowing through the porous filter substrate 1210 between the first surface 1212 and the second surface 1214.

[0116]

[0142] The particulate filter 1200 may also include a plurality of conductors 1220 coupled to the porous filter substrate 1210. The conductors 1220 may be generally parallel to one another along the porous filter substrate 1210. In addition, the particulate filter 1200 may include a plurality of input nodes 1222 in signal communication with the plurality of conductors 1220 and configured to receive a voltage signal from an input signal source 1224. The plurality of conductors 1220 are configured to generate an electric field on at least one of the first surface 1212 or the second surface 1214 of the porous filter substrate 1210 in response to the plurality of input nodes 1222 receiving a voltage signal from the input signal source 1224. As described above, when the electric field is generated, the electric field may repel and remove particulates accumulated on the porous filter substrate 1210 and / or repel the particulates to prevent the particulates from accumulating on the porous filter substrate 1210.

[0117]

[0143] In examples, the conductors 1220 can be bonded onto at least one surface selected from the first surface 1212 of the porous filter substrate 1210 and the second surface 1214 of the porous filter substrate 1210. For example, as described above, the conductors 1220 can be bonded to the first surface 1212 and / or the second surface 1214 of the porous filter substrate 1210 by weaving, screen printing, and / or stamping, as described above and shown, for example, in Figures 7A-7D.

[0118]

[0144] The particulate filter 1200 may further include any other features of the particulate filters 100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100 described above and / or shown in Figures 1-11. For example, the particulate filter 1200 may include a frame 1216 in some implementations to help provide structural rigidity around the particulate filter 1200, or the particulate filter 1200 may omit the frame 1216 in other embodiments in which the porous filter substrate 1210 is freestanding. Additionally, for example, the particulate filter 1200 may include a gasket 1218 for sealing the interface between the frame 1216 and the porous filter substrate 1210, as described above.

[0119]

[0145] In some examples, the particulate filter 1200 may also include an input signal source 1224, as described above. Thus, as described above, the input signal source 1224 may be operated in a first operating mode that causes the conductor 1220 to generate an electric field in the form of a standing wave, and / or the input signal source 1224 may be operated in a second operating mode that causes the conductor 1220 to generate an electric field in the form of a traveling wave. Thus, in the first operating mode, the input signal source 1224 may generate a voltage signal such that the electric field forms a standing wave on at least one of the first surface 1212 or the second surface 1214 of the porous filter substrate 1210. Meanwhile, in the second operating mode, the input signal source 1224 may generate a voltage signal such that the electric field forms a traveling wave. More specifically, as described above, the conductor 1220 can extend in a first direction along the porous filter substrate 1210, and the input signal source 1224 can generate a voltage signal such that the electric field forms a traveling wave that travels in a second direction transverse to the first direction along at least one of the first surface 1212 or the second surface 1214.

[0120]

[0146] 12-13, the operation of the input signal source 1224 can be controlled by a controller 1228 in communication with the input signal source 1224. In an example, the controller 1228 can be implemented using hardware, software, and / or firmware. For example, the controller 1228 can include one or more processors 1230 and a non-transitory computer-readable medium (e.g., volatile and / or non-volatile memory 1232) that stores machine language instructions or other executable instructions. The instructions, when executed by the one or more processors 1230, can cause the components of the particulate filter 1200 (e.g., the input signal source 1224) to perform various operations described herein. Thus, the controller 1228 can also receive data and store the data in memory.

[0121]

[0147] In some examples, the particulate filter 1200 may additionally or alternatively include a particulate collection receptacle 1226 at the periphery of the porous filter substrate 1210, configured to collect particulates removed from the porous filter substrate 1210 by the electric field, as described above. In some implementations, the particulate collection receptacle 1226 may be positioned along the path of the particulates when the traveling wave of the electric field moves the particulates in the second direction. In this manner, the electric field generated by the conductor 1220 may separate the particulates from the porous filter substrate 1210 and move the particulates to the particulate collection receptacle 1226. As described above, the particulate collection receptacle 1226 may help to increase cleaning efficiency, at least because the particulate collection receptacle 1226 may help to concentrate the particulates in a central location that can be cleaned more easily and quickly than the porous filter substrate 1210.

[0122]

[0148] Also, in some examples, the particulate filter 1200 can include an actuator 1248 operable to adjust the shape of the porous filter substrate 1210 as described above with respect to FIG. 6. For example, the actuator 1248 can be operated to move one or more accordion-folded pleats (e.g., accordion-folded pleats 636 in FIG. 6) of the porous filter substrate 1210 relative to at least one other accordion-folded pleat (and / or frame 1216). As described above, while the accordion-folded pleats are thus opened, the conductor 1220 can generate an electric field to repel and / or remove particulates. Opening the accordion-folded pleats using the actuator 1248 can help improve cleaning efficiency.

[0123]

[0149] In some examples, the particulate filter 1200 can include a sensor 1234 that can measure the amount of particulates (e.g., dust) on the porous filter substrate 1210 as described above. Furthermore, the sensor 1234 can communicate with the controller 1228, and the controller 1228 can use the sensor signal received from the sensor 1234 based on (i) causing the generation of an electric field on the conductor 1220 and / or (ii) determining the electrical parameters of the voltage signal for generating the electric field on the conductor 1220 as described above.

[0124]

[0150] In Fig. 12-13, the gas recirculation system 1276 includes a duct 1278 having an inlet 1280 and an outlet 1282. The inlet 1280 of the duct 1278 is configured to receive gas exiting the particulate filter 1200 at the second surface 1214 into the duct 1278. The outlet 1282 of the duct 1278 is configured to output gas from the duct 1278 to the particulate filter 1200 at the first surface 1212. Thus, the duct 1278 can provide a conduit for recirculating the gas from the second surface 1214 to the first surface 1212 so that the gas can pass through the porous filter substrate 1210 multiple times. This can help remove a relatively large amount of particulates from the gas compared to a filter system that passes the gas through the porous filter substrate 1210 once.

[0125]

[0151] In an example, the filter system 1252 can controllably adjust the electric field generated by the conductors 1220 on the first surface 1212 and / or the second surface 1214 while the gas is recirculated multiple times through the porous filter substrate 1210. For example, the controller 1228 can: (i) cause the input signal source 1224 to provide a first voltage signal while the gas flows through the porous filter substrate 1210 a first time, and (ii) cause the input signal source 1224 to provide a second voltage signal while the gas flows through the porous filter substrate 1210 a second time after the gas has been recirculated by the gas recirculation system 1276. The first voltage signal is different from the second voltage signal. Because different types of particulates can be affected differently by different types of electric fields, adjusting the electric field while recirculating the gas through the porous filter substrate 1210 can more effectively remove a greater variety of particulate types from a given volume of gas than when the volume of gas passes through the porous filter substrate 1210 all at once.

[0126]

[0152] As described above, the first voltage signal is different from the second voltage signal. In some examples, the first voltage signal has a first voltage level and a first waveform, the second voltage signal has a second voltage level and a second waveform, and the first voltage level is different from the second voltage level. In some examples, the first voltage signal has a first voltage level and a first waveform, the second voltage signal has a second voltage level and a second waveform, and the first waveform is different from the second waveform. In a further example, the gas recirculation system 1276 recirculates gas through the porous filter substrate 1210, while the controller 1228 can cause the input signal source 1224 to provide M voltage signals that differ from each other in at least one of the voltage levels or waveforms, where N and M are integer values ​​greater than 1.

[0127]

[0153] In some examples, the gas recirculation system 1276 can further include one or more dampers to help control the flow path of gas within the gas recirculation system 1276. For example, as shown in FIG. 13, the gas recirculation system 1276 can include a first damper 1284 downstream of the inlet 1282 and a second damper 1286 upstream of the outlet 1282. The first damper 1284 is operable between a first position (shown in FIG. 13 with dashed lines) and a second position (shown in FIG. 13 with solid lines). When the first damper 1284 is in the first position, the first damper 1284 is configured to direct gas from the second surface 1214 toward the inlet 1280 of the duct 1278 of the gas recirculation system 1276. When the first damper 1284 is in the second position, the first damper 1284 is configured to allow gas to flow away from the inlet 128 of the duct 1278 of the gas recirculation system 1276. In this arrangement, the first damper 1284 can be actuated to the first position to recirculate gas through the particulate filter 1200, and the first damper 1284 can be actuated to the second position to vent the gas from the particulate filter 1200 and out of the filter system 1252 after recirculation and filtration is completed.

[0128]

[0154] The second damper 1286 may also be actuable between a first position (shown in dashed lines in FIG. 13) and a second position (shown in solid lines in FIG. 13). When the second damper 1286 is in the first position, the second damper 1286 is configured to direct gas from the outlet 1282 of the duct 1278 to the first surface 1212 of the porous filter substrate 1210. When the second damper 1286 is in the second position, the second damper 1286 is configured to allow gas to flow through the outlet 1282 of the duct 1278 to the first surface 1212 of the porous filter substrate 1210. In this arrangement, the second damper 1286 can be actuated to the second position to allow gas to enter the filter system 1252 initially and provide it towards the particulate filter 1200, and the second damper 1286 can be actuated to the first position to help recirculate the gas through the particulate filter 1200.

[0129]

[0155] In some examples, the controller 1228 can be in communication with the first damper 1284 and the second damper 1286. In one embodiment, the controller 1228 can actuate the second damper 1286 to the second position to allow an initial amount of gas to flow into the gas recirculation system 1276 and to the first surface 1212 of the porous filter substrate 1210. To recirculate the initial amount of gas, the controller 1228 can actuate the first damper 1284 and the second damper 1286 to their respective first positions. After passing the initial amount of gas through the porous filter substrate 1210 multiple times, the controller 1228 can actuate the first damper 1284 from the first position to the second position to exhaust the gas from the filter system 1252. For example, in implementations in which gas passes through the porous filter substrate 1210 a second time, the controller 1228 can actuate the first damper 1284 from the first position to the second position after the gas flows through the porous filter substrate 1210 a second time. The controller 1228 can also actuate the second damper 1286 to the second position to allow a subsequent volume of gas to flow into the filter system 1252, and the method can repeat.

[0130]

[0156] In some examples, the gas recirculation system 1276 can also include a recirculation fan 1288 configured to increase the flow of gas from the inlet 1280 to the outlet 1282. In this manner, the gas recirculation system 1276 can help improve the flow of gas, which may help to recirculate and filter the gas more quickly and / or efficiently compared to implementations that omit the recirculation fan 1288. In FIG. 13, the recirculation fan 1288 is in a position between the inlet 1280 and the outlet 1282 in the duct 1278. This can beneficially reduce or mitigate the recirculation fan 1288 impeding the flow of gas as the gas is being exhausted from the filter system 1252 (e.g., when the first damper 1284 is in the second position). However, in other examples, the recirculation fan 1288 can be located in a different position (e.g., outside the duct 1278).

[0131]

[0157] As described above, the controller 1228 can cause the input signal source 1224 to provide multiple voltage signals having different electrical characteristics to generate multiple electric fields that can interact differently with different types of particulates in the gas. In some examples, the controller 1228 can additionally or alternatively adjust the shape of the porous filter substrate 1210 while the gas is recirculating multiple times through the porous filter substrate. For example, as described above, the filter system 1252 can include an actuator 1248 that can adjust the shape of the porous filter substrate 1210 from a first shape to a second shape in some implementations. The controller 1228 can be in communication with the actuator 1248, and the controller 1228 can be configured to: (i) cause the actuator 1248 to place the porous filter substrate 1210 in a first shape while gas flows through the porous filter substrate 1210 at a first time, and (ii) cause the actuator 1248 to place the porous filter substrate 1210 in a second shape while gas flows through the porous filter substrate 1210 at a second time after the gas has been recirculated by the gas recirculation system 1276. This can help expose the gas to different portions of the porous filter substrate 1210 during different passes through the porous filter substrate 1210, which can help improve filtering efficiency.

[0132]

[0158] In one embodiment, the porous filter substrate 1210 has a plurality of accordion-fold pleats including a plurality of panels and a plurality of fold lines between each one of the plurality of panels (e.g., accordion-fold pleat 636 including panel 638 and fold line 640 shown in FIG. 6). In this implementation, the actuator 1248 can move at least one panel of the plurality of panels relative to at least another panel of the plurality of panels to adjust the shape of the porous filter substrate 1210 from a first shape to a second shape. In implementations in which gas is further recirculated, the controller 1228 can cause the actuator 1248 to further adjust the shape of the porous filter substrate 1210. For example, the controller 1228 can cause the actuator 1248 to further move at least one additional panel relative to at least another panel to further adjust the shape of the porous filter substrate 1210.

[0133] Referring now to FIG. 14, a flow chart of a method 1400 of removing particles from a filter is shown according to an example. As shown in FIG. 14, in block 1412, the method 1400 includes receiving a voltage signal from an input signal source at a plurality of input nodes of a particulate filter. The particulate filter includes a porous filter substrate and a plurality of conductors coupled to the porous filter substrate. The porous filter substrate is configured to filter a gas flowing between a first surface of the porous filter substrate and a second surface of the porous filter substrate. The plurality of conductors are generally parallel to each other along the porous filter substrate. The plurality of input nodes are in signal communication with the plurality of conductors.

[0134]

[0160] At block 1414, the method 1400 includes generating an electric field on at least one of the first surface or the second surface of the porous filter substrate using a voltage signal on the plurality of conductors. At block 1416, the method 1400 includes removing particulates from at least one of the first surface or the second surface using the electric field.

[0135]

[0161] 15-21 illustrate additional aspects of method 1400 according to further examples. In one example, a plurality of conductors extend in a first direction along a porous filter substrate. As shown in FIG. 15, generating an electric field at block 1414 using voltage signals of the plurality of conductors can include forming a traveling wave at block 1418 that travels along at least one of the first surface or the second surface in a second direction transverse to the first direction.

[0136]

[0162] As shown in FIG. 16, using an electric field to remove particulates from at least one of the first surface or the second surface at block 1416 may include using an electric field to move the particulates in a second direction toward a particulate collection receptacle at block 1420, and storing the particulates in the particulate collection receptacle at block 1422.

[0137]

[0163] As shown in FIG. 17 , generating an electric field at block 1414 using a voltage signal of multiple conductors may include (i) using the electric field to first form a standing wave to detach the particulate from at least one of the first surface or the second surface at block 1424, and (ii) after forming the standing wave at block 1424, forming a second traveling wave to move the particulate in a second direction at block 1426.

[0138]

[0164] 18, receiving voltage signals from an input signal source at a plurality of input nodes in block 1412 may include receiving a first voltage signal at a first time in block 1428 and receiving a second voltage signal at a second time in block 1430. An electrical parameter of the first voltage signal may have a different value than a value of the electrical parameter of the second voltage signal.

[0139]

[0165] As shown in Figure 19, the method 1400 may also include measuring, by a sensor, an amount of particulates on the porous filter substrate at block 1432. In Figure 19, using the controller and based on the amount of particulates measured by the sensor, the method 1400 may further include determining to remove the particulates from the porous filter substrate at block 1434. In response to determining to remove the particulates from the porous filter substrate at block 1434, the method 1400 may include providing a voltage signal from an input signal source to a plurality of input nodes at block 1436.

[0140]

[0166] As shown in Figure 20, the method 1400 may also include measuring, by the sensor, an amount of particulates on the porous filter substrate at block 1438. Further in Figure 20, the method 1400 may include, by the controller, receiving, from the sensor, a sensor signal indicative of an amount of particulates on the porous filter substrate at block 1440. The method 1400 may further include determining a value of an electrical parameter of the voltage signal at block 1442 based on the amount of particulates indicated by the sensor signal. The method 1400 may also include providing, by an input signal source, a voltage signal having an electrical parameter having a value at block 1444 to a plurality of input nodes.

[0141]

[0167] As shown in Figure 21, the method 1400 may further include filtering the gas flowing through a filter of the porous filter substrate between a first surface of the porous filter substrate and a second surface of the porous filter substrate at block 1446, and adjusting the shape of the porous filter substrate from a first shape to a second shape at block 1448 using an actuator. In Figure 21, filtering the gas flowing through the porous filter substrate at block 1446 may include filtering the gas flowing through the porous filter substrate while at block 1450 the porous filter substrate is in a first shape. Also in Figure 21, removing particulates from at least one of the first surface or the second surface at block 1416 using an electric field may include removing particulates from at least one of the first surface or the second surface while the porous filter substrate is in a second shape at block 1452.

[0142]

[0168]

[00136] Referring now to Figure 22, a flow chart of a method 2200 of making a filter is shown, according to an example. As shown in Figure 22, the method 2200 includes bonding a porous filter substrate to a frame at block 2212. The porous filter substrate includes a first surface and a second surface. The porous filter substrate is configured to filter gas flowing through the porous filter substrate between the first surface and the second surface.

[0143]

[0169] At block 2214, the method 2200 includes coupling the plurality of conductors to the porous filter substrate such that the plurality of conductors are substantially parallel to one another along the porous filter substrate. At block 2216, the method 2200 includes forming a plurality of input nodes in signal communication with the plurality of conductors, configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0144]

[0170] One or more blocks shown in FIG. 14-FIG. 22 may represent a module, segment, or portion of program code, which includes one or more instructions executable by a processor to implement a particular logical function or step in a method. The program code may be stored in any type of computer readable medium or data storage device, such as a storage device including a disk or hard drive. Furthermore, the program code may be encoded in a computer readable storage medium in machine readable form, or other non-transitory medium or article of manufacture. The computer readable medium may include non-transitory computer readable media or memory, such as computer readable media that store data for a short period of time, such as a register memory, a processor cache, and a random access memory (RAM). The computer readable medium may also include non-transitory media, such as secondary or permanent long term storage, such as a read only memory (ROM), an optical or magnetic disk, a compact disk read only memory (CD-ROM). The computer readable medium may also be any other volatile or non-volatile storage system. The computer readable medium may be considered, for example, as a tangible computer readable storage medium.

[0145]

[0171] In some cases, components of the devices and / or systems described herein may be configured (using hardware and / or software) to perform functions such that the components are actually configured and structured to enable such performance. An example configuration then includes one or more processors that execute instructions that cause the system to perform a function. Similarly, components of the devices and / or systems may be configured to be arranged or adapted, capable, or suitable to perform a function, such as when operated in a particular manner.

[0146]

[0172] Additionally, the disclosure includes examples that comply with the following provisions:

[0147] Clause 1. A particulate filter includes: a porous filter substrate including a first surface and a second surface, the particulate filter being configured to filter gas flowing through the porous filter substrate between the first surface and the second surface; a plurality of conductors coupled to the porous filter substrate and substantially parallel to one another along the porous filter substrate; and a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source, the plurality of conductors being configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving voltage signals from the input signal source.

[0148] Clause 2. The particulate filter of clause 1, wherein a plurality of conductors are coupled to a first surface of the porous filter substrate and to a second surface of the porous filter substrate.

[0149] Clause 3. The particulate filter of clause 1 or 2, wherein the plurality of conductors comprises a plurality of conductive fibers woven into a porous filter substrate.

[0150] Clause 4. The particulate filter of clause 1 or 2, wherein the plurality of conductors comprises a conductive material printed on at least one of the first surface of the porous filter substrate or the second surface of the porous filter substrate.

[0151] Clause 5. The particulate filter of any of clauses 1-4, wherein the plurality of conductors extend in a first direction along the porous filter substrate, and the particulate filter further includes an input signal source configured to generate a voltage signal such that the electric field forms a traveling wave along at least one of the first surface or the second surface that travels in a second direction transverse to the first direction.

[0152] Clause 6. The particulate filter of any of clauses 1 to 5, further comprising an input signal source configured to generate a voltage signal such that the electric field forms a standing wave on at least one of the first surface or the second surface.

[0153] Clause 7. A particulate filter of any of clauses 1 to 6, further comprising: a sensor configured to measure an amount of particulates on the porous filter substrate; and a controller in communication with the sensor and an input signal source, the controller being configured to: receive a sensor signal from the sensor indicative of an amount of particulates on the porous filter substrate; determine a value of an electrical parameter of the voltage signal based on the amount of particulates indicated by the sensor signal; and cause the input signal source to supply voltage signals having an electrical parameter having a value to a plurality of input nodes.

[0154] Clause 8. The particulate filter of any of clauses 1-7, further comprising a particulate collection receptacle around the porous filter substrate and configured to collect particulates removed from the porous filter substrate by the electric field.

[0155] Clause 9. The particulate filter of any of clauses 1 to 8, wherein the porous filter substrate has a plurality of accordion fold pleats including a plurality of panels and a plurality of fold lines between each panel of the plurality of panels, and each conductor extends along a respective fold line of the plurality of fold lines.

[0156] Clause 10. The particulate filter of any of clauses 1-9, wherein the porous filter substrate has a plurality of accordion fold pleats including a plurality of panels and a plurality of fold lines between each panel of the plurality of panels, and the plurality of conductors extend across the plurality of panels and the plurality of fold lines.

[0157] Clause 11. The particulate filter of any of clauses 1-10, further comprising a frame coupled to and supporting the porous filter substrate, the porous filter substrate including a plurality of filter media arranged in a plane parallel between a first surface and a second surface, and a plurality of conductors coupled to the plurality of filter media filtration media defining the first surface of the porous filter substrate.

[0158] Clause 12. A method for removing particulates from a particulate filter, the method comprising: receiving voltage signals from an input signal source at a plurality of input nodes of a particulate filter, the particulate filter including a porous filter substrate and a plurality of conductors coupled to the porous filter substrate, the porous filter substrate being configured to filter gas flowing between a first surface of the porous filter substrate and a second surface of the porous filter substrate, the plurality of conductors being generally parallel to one another along the porous filter substrate, the plurality of input nodes being in signal communication with the plurality of conductors; generating an electric field on at least one of the first surface or the second surface of the porous filter substrate using the voltage signals of the plurality of conductors; and removing particulates from at least one of the first surface or the second surface using the electric field.

[0159] Clause 13. The method of clause 12, wherein a plurality of conductors extend in a first direction along the porous filter substrate, and generating an electric field using a voltage signal on the plurality of conductors includes forming a traveling wave that travels in a second direction transverse to the first direction along at least one of the first surface or the second surface.

[0160] Clause 14. The method of clause 12 or 13, wherein removing particulates from at least one of the first surface or the second surface using an electric field includes: using an electric field to move the particulates in a second direction toward a particulate collection receptacle; and containing the particulates in the particulate collection receptacle.

[0161] Clause 15. The method of any of clauses 12-14, wherein generating an electric field using a voltage signal on a plurality of conductors includes forming a standing wave with the electric field at a first time to separate the particulate from at least one of the first surface or the second surface; and after forming the standing wave, forming a traveling wave at a second time to move the particulate in a second direction.

[0162] Clause 16. The method of clause 15, wherein receiving voltage signals from an input signal source at a plurality of input nodes includes receiving a voltage signal at a first time; and receiving a second voltage signal at a second time, wherein an electrical parameter of the first voltage signal has a value that differs from a value of the electrical parameter of the second voltage signal.

[0163] Clause 17. The method of any of clauses 12-16, further comprising: measuring an amount of particulates on the porous filter substrate by a sensor; deciding, using a controller, to remove particulates from the porous filter substrate based on the amount of particulates measured by the sensor; and in response to deciding to remove particulates from the porous filter substrate, providing voltage signals from an input signal source to a plurality of input nodes.

[0164] Clause 18. The method of any of clauses 12-17, further comprising: measuring, by a sensor, an amount of particulates on the porous filter substrate; receiving, by a controller, a sensor signal from the sensor indicative of the amount of particulates on the porous filter substrate; determining a value of an electrical parameter of the voltage signal based on the amount of particulates indicated by the sensor signal; and providing, by an input signal source, voltage signals having the electrical parameter having a value to a plurality of input nodes.

[0165] Clause 19. The method of any of clauses 12-18, further comprising: filtering the gas flowing through the filter of the porous filter substrate between a first surface of the porous filter substrate and a second surface of the porous filter substrate; and adjusting a shape of the porous filter substrate from the first shape to a second shape using the actuator, wherein filtering the gas flowing through the porous filter substrate comprises filtering the gas flowing through the porous filter substrate while the porous filter substrate is in the first shape, and wherein removing particulates from at least one of the first surface or the second surface using the electric field comprises removing particulates from at least one of the first surface or the second surface while the porous filter substrate is in the second shape.

[0166] Clause 20. A method of making a filter, comprising: coupling a porous filter substrate to a frame, the porous filter substrate including a first surface and a second surface, the porous filter substrate being configured to filter gas flowing through the porous filter substrate between the first surface and the second surface; coupling a plurality of conductors to the porous filter substrate such that the conductors are generally parallel to one another along the porous filter substrate; and forming a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source, the plurality of conductors being configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0167] Clause 21. A filter system comprising: a porous filter substrate including a first surface and a second surface and configured to filter a gas flowing through the porous filter substrate between the first surface and the second surface; a plurality of conductors coupled to the porous filter substrate, the plurality of conductors being generally parallel to one another along the porous filter substrate; and a particulate filter including a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source, the plurality of conductors being configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving the voltage signals from the input signal source; and an electromagnetic field generator disposed upstream of the particulate filter along a gas flow path and operable to generate an electromagnetic field configured to charge particles in the gas before the gas flows through the porous filter substrate.

[0168] Clause 22. The filter system of clause 21, wherein the electromagnetic field generator includes a mesh structure that is offset from the first surface by a gap between the electromagnetic field generator and the particulate filter.

[0169] Clause 23. The filter system of clause 22, wherein the mesh structure includes a plurality of conductive strands defining a plurality of apertures, the plurality of apertures having a size greater than a size of particulates in the gas.

[0170] Clause 24. The filter system of any of clauses 21-23, wherein a plurality of conductors are bonded onto at least one surface selected from the first surface of the porous filter substrate and the second surface of the porous filter substrate.

[0171] Clause 25. The filter system of any of clauses 21-24, wherein the plurality of conductors comprises a plurality of conductive fibers woven into a porous filter substrate.

[0172] Clause 26. The filter system of any of clauses 21-25, wherein the plurality of conductors extend in a first direction along the porous filter substrate, and the particulate filter further includes an input signal source configured to generate a voltage signal such that the electric field forms a traveling wave along at least one of the first surface or the second surface that travels in a second direction transverse to the first direction.

[0173] Clause 27. The filter system of any of clauses 21-26, further comprising an input signal source configured to generate a voltage signal such that an electric field forms a standing wave on at least one of the twenty-first surface or the second surface.

[0174] Clause 28. The filter system of any of clauses 21-27, further comprising a particulate collection receptacle around the porous filter substrate and configured to collect particulates dislodged from the porous filter substrate by the electric field.

[0175] Clause 29. A filter system, comprising: a porous filter substrate including a first surface and a second surface, the porous filter substrate being configured to filter gas flowing through the porous filter substrate in a direction from the first surface to the second surface; a particulate filter including a plurality of conductors coupled to the porous filter substrate, the plurality of conductors being generally parallel to one another along the porous filter substrate; and a plurality of input nodes in signal communication with the plurality of conductors and configured to receive a voltage signal from an input signal source; and a gas recirculation system including a duct having an inlet and an outlet, the inlet of the duct having a putty on the second surface disposed within the duct. a gas recirculation system configured to receive gas exiting the particulate filter, the duct outlet configured to output the gas from the duct to the particulate filter on a first surface; and a controller in communication with an input signal source, the controller configured to cause the input signal source to provide a first voltage signal while the gas flows through the porous filter substrate at a first time and after the gas has been recirculated by the gas recirculation system, and to cause the input signal source to provide a second voltage signal while the gas flows through the porous filter substrate at a second time, the first voltage signal being different from the second voltage signal.

[0176] Clause 30. The filter system of clause 29, wherein the first voltage signal has a first voltage level and a first waveform, and the second voltage signal has a second voltage level and a second waveform, the first voltage level being different from the second voltage level.

[0177] Clause 31. The filter system of clause 29 or 30, wherein the first voltage signal has a first voltage level and a first waveform, and the second voltage signal has a second voltage level and a second waveform, the first waveform being different from the second waveform.

[0178] Clause 32. The filter system of any of clauses 29-31, further comprising an actuator configured to adjust a shape of the porous filter substrate from a first shape to a second shape, the controller being in communication with the actuator, the controller being configured to cause the actuator to position the porous filter substrate in the first shape while gas flows through the porous filter substrate at a first time and after the gas has been recirculated by the gas recirculation system, and to cause the actuator to position the porous filter substrate in the second shape while gas flows through the porous filter substrate at a second time.

[0179] Clause 33. The filter system of clause 32, wherein the porous filter substrate has a plurality of accordion fold pleats including a plurality of panels and a plurality of fold lines between each panel of the plurality of panels, and the actuator is configured to move at least one panel of the plurality of panels relative to at least another panel of the plurality of panels to adjust a shape of the porous filter substrate from a first shape to a second shape.

[0180] Clause 34. The filter system of any of clauses 29 to 33, wherein the gas recirculation system is configured such that when the damper is in a first position, the damper directs gas towards an inlet of a duct of the gas recirculation system, and when the damper is in a second position, the damper allows gas to flow away from the inlet of the duct of the gas recirculation system.

[0181] Clause 35. The filter system of clause 34, wherein a controller is in communication with the damper, and the controller is configured to actuate the damper from the first position to the second position after the gas flows through the porous filter substrate a second time.

[0182] Clause 36. The filter system of any of clauses 29 to 35, wherein the gas recirculation system includes a recirculation fan configured to increase the flow of gas from the inlet to the outlet.

[0183] Clause 37. The filter system of any of clauses 29-36, further comprising a particulate collection receptacle around the porous filter substrate and configured to collect particulates removed from the porous filter substrate by the electric field.

[0184] Clause 38. A filter system comprising: a porous filter substrate including a first surface and a second surface, the porous filter substrate configured to filter gas flowing through the porous filter substrate between the first surface and the second surface; a plurality of conductors coupled to the porous filter substrate and substantially parallel to one another along the porous filter substrate; and a particulate filter including a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from an input signal source, the plurality of conductors configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to the plurality of input nodes receiving voltage signals from the input signal source; and a gas mover disposed upstream of the particulate filter along a gas flow path, the gas mover operable to generate turbulence in the gas before the gas flows through the porous filter substrate.

[0185] Clause 39. The filter system of clause 38, wherein a plurality of conductors are coupled to at least one surface selected from the first surface of the porous filter substrate and the second surface of the porous filter substrate.

[0186] Clause 40. A filter system as claimed in clause 38 or 39, wherein the gas mover includes a fan.

[0187] Clause 41. A filter system, comprising: a porous filter substrate including a first surface and a second surface, the porous filter substrate being configured to filter gas flowing through the porous filter substrate in a direction from the first surface to the second surface; and a particulate filter including a plurality of conductors coupled to the porous filter substrate, the plurality of conductors being generally parallel to one another along the porous filter substrate and configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to a voltage signal from an input signal source; and a gas recirculation system including a duct having an inlet and an outlet, the inlet of the duct being configured to receive gas exiting the particulate filter at the second surface into the duct, the duct having an inlet configured to receive gas exiting the particulate filter at the second surface into the duct. a gas recirculation system configured to output gas from the duct to the particulate filter on the first surface, the outlet of the filter system; and a controller in communication with an input signal source, the controller configured to cause the input signal source to provide a first voltage signal to the plurality of conductors while the gas flows through the porous filter substrate at a first time and after the gas has been recirculated from the inlet to the outlet by the gas recirculation system, and to cause the input signal source to provide a second voltage signal to the plurality of conductors while the gas flows through the porous filter substrate at a second time, the first voltage signal being different from the second voltage signal such that an electric field is adjusted between when the gas flows through the porous filter substrate at the first time and when the gas flows through the porous filter substrate at the second time.

[0188] Clause 42. The filter system of clause 41, wherein the first voltage signal has a first voltage level and a first waveform, and the second voltage signal has a second voltage level and a second waveform, the first voltage level being different from the second voltage level.

[0189] Clause 43. The filter system of clause 41 or 42, wherein the first voltage signal has a first voltage level and a first waveform and the second voltage signal has a second voltage level and a second waveform, the first waveform being different from the second waveform.

[0190] Clause 44. The filter system of any of clauses 41 to 31, further comprising an actuator configured to adjust a shape of the porous filter substrate from a first shape to a second shape, the controller being in communication with the actuator, the controller being configured to cause the actuator to position the porous filter substrate in the first shape while gas flows through the porous filter substrate at a first time and after the gas has been recirculated by the gas recirculation system, and to cause the actuator to position the porous filter substrate in the second shape while gas flows through the porous filter substrate at a second time.

[0191] Clause 45. The filter system of any of clauses 41-44, wherein the porous filter substrate has a plurality of accordion fold pleats including a plurality of panels and a plurality of fold lines between each panel of the plurality of panels, and the actuator is configured to move at least one panel of the plurality of panels relative to at least another panel of the plurality of panels to adjust a shape of the porous filter substrate from a first shape to a second shape.

[0192] Clause 46. The filter system of any of clauses 41-45, wherein the gas recirculation system further includes a damper actuable between a first position and a second position, wherein when the damper is in the first position the damper is configured to direct gas to an inlet of a duct of the gas recirculation system and when the damper is in the second position the damper is configured to allow gas to flow away from the inlet of the duct of the gas recirculation system, a controller is in communication with the damper, and the controller is configured to actuate the damper from the first position to the second position after the gas has flowed through the porous filter substrate a second time.

[0193] Clause 47. The filter system of any of clauses 41-46, wherein the gas recirculation system further includes a first damper downstream of the inlet and a second damper upstream of the outlet, the controller being in communication with the first damper and the second damper, and the controller being configured to actuate the first damper and the second damper to control a flow path of the gas within the gas recirculation system.

[0194] Clause 48. The filter system of clause 47, wherein the first damper is operable between a first position and a second position, and when the first damper is in the first position, the first damper is configured to direct gas from the second surface to an inlet of a duct of the gas recirculation system, and when the first damper is in the second position, the first damper is configured to allow gas to flow out of the inlet of the duct of the gas recirculation system, and the second damper is operable between the first position and the second position, and when the second damper is in the first position, the second damper is configured to direct gas from an outlet of the duct to the first surface of the porous filter substrate, and when the second damper is in the second position, the second damper is configured to allow gas to flow through the outlet of the duct to the first surface of the porous filter substrate.

[0195] Clause 49. The filter system of any of clauses 41 to 48, wherein the gas recirculation system includes a recirculation fan configured to increase the flow of gas from the inlet to the outlet.

[0196] Clause 50. A filter system as claimed in clause 49, wherein a recirculation fan is positioned within the duct between the inlet and the outlet.

[0197] Clause 51. The filter system of any of clauses 41-50, further comprising a particulate collection receptacle around the porous filter substrate and configured to collect particulates removed from the porous filter substrate by the electric field.

[0198] Clause 52. A filter system, comprising: a porous filter substrate including a first surface and a second surface, the porous filter substrate configured to filter gas flowing through the porous filter substrate in a direction from the first surface to the second surface; a particulate filter including a plurality of conductors coupled to the porous filter substrate, the plurality of conductors being generally parallel to one another along the porous filter substrate, the plurality of conductors being configured to generate an electric field on at least one of the first surface or the second surface of the porous filter substrate in response to a voltage signal from an input signal source; and a gas recirculation system including a duct having an inlet and an outlet, the inlet of the duct configured to receive particulates at the second surface within the duct. a gas recirculation system configured to receive gas exiting the particulate filter, the outlet of the duct configured to output the gas from the duct to the particulate filter at a first surface; an actuator configured to adjust a shape of the porous filter substrate from a first shape to a second shape; and a controller in communication with the actuator, the controller configured to cause the actuator to position the porous filter substrate in the first shape while the gas flows through the porous filter substrate at a first time and after the gas has been recirculated from the inlet to the outlet by the gas recirculation system, and to cause the actuator to position the porous filter substrate in the second shape while the gas flows through the porous filter substrate at a second time.

[0199] Clause 53. The filter system of clause 52, wherein the porous filter substrate has a plurality of accordion fold pleats including a plurality of panels and a plurality of fold lines between each panel of the plurality of panels, and the actuator is configured to move at least one panel of the plurality of panels relative to at least another panel of the plurality of panels to adjust a shape of the porous filter substrate from a first shape to a second shape.

[0200] Clause 54. The filter system of clause 52 or 53, wherein the gas recirculation system further includes a damper actuable between a first position and a second position, when the damper is in the first position the damper is configured to direct gas to an inlet of a duct of the gas recirculation system and when the damper is in the second position the damper is configured to allow gas to flow away from the inlet of the duct of the gas recirculation system, a controller is in communication with the damper, and the controller is configured to actuate the damper from the first position to the second position after the gas has flowed through the porous filter substrate a second time.

[0201] Clause 55. The filter system of any of clauses 52-54, wherein the gas recirculation system further includes a first damper downstream of the inlet and a second damper upstream of the outlet, the controller being in communication with the first damper and the second damper, and the controller being configured to actuate the first damper and the second damper to control a flow path of gas within the gas recirculation system.

[0202] Clause 56. The filter system of clause 55, wherein the first damper is operable between a first position and a second position, and when the first damper is in the first position, the first damper is configured to direct gas from the second surface to an inlet of a duct of the gas recirculation system, and when the first damper is in the second position, the first damper is configured to allow gas to flow out of the inlet of the duct of the gas recirculation system, and the second damper is operable between the first position and the second position, and when the second damper is in the first position, the second damper is configured to direct gas from an outlet of the duct to the first surface of the porous filter substrate, and when the second damper is in the second position, the second damper is configured to allow gas to flow through the outlet of the duct to the first surface of the porous filter substrate.

[0203] Clause 57. The filter system of any of clauses 52-56, wherein the gas recirculation system includes a recirculation fan configured to increase the flow of gas from the inlet to the outlet.

[0204] Clause 58. A filter system according to any of clauses 52 to 57, wherein a recirculation fan is positioned in the duct between the inlet and the outlet.

[0205] Clause 59. The filter system of any of clauses 52-58, further comprising a particulate collection receptacle around the porous filter substrate and configured to collect particulates removed from the porous filter substrate by the electric field.

[0206] Clause 60. A method of removing particulates from a particulate filter comprising: receiving a first voltage signal from an input signal source at a plurality of input nodes of a particulate filter, the particulate filter including a porous filter substrate and a plurality of conductors coupled to the porous filter substrate, the porous filter substrate being configured to filter gas flowing through the porous filter substrate from a first surface of the porous filter substrate to a second surface of the porous filter substrate, the plurality of conductors being generally parallel to one another along the porous filter substrate, the plurality of input nodes being in signal communication with the plurality of conductors; generating an electric field on at least one of the first surface or the second surface of the porous filter substrate using the first voltage signal on the plurality of conductors while the gas flows through the porous filter substrate at a first time; and after the gas flows through the porous filter substrate at the first time, generating an electric field on at least one of the first surface or the second surface of the porous filter substrate using a gas recirculation system. recirculating gas from the second surface of the porous filter substrate to the first surface of the porous filter substrate, the gas recirculation system including a duct having an inlet and an outlet, the inlet of the duct configured to receive into the duct gas exiting the particulate filter at the second surface and the outlet of the duct configured to output the gas from the duct to the particulate filter at the first surface; generating an electric field on at least one of the first surface or the second surface of the porous filter substrate using a second voltage signal on a plurality of conductors while the gas flows once more through the porous filter substrate, the first voltage signal being different from the second voltage signal such that the electric field is adjusted between when the gas flows through the porous filter substrate at a first time and when the gas flows through the porous filter substrate at a second time.

[0207]

[0173] The description of the different advantageous arrangements is presented for purposes of illustration and explanation, and is not intended to be exhaustive or limited to the disclosed forms of the examples. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different advantageous examples may exhibit different advantages over other advantageous examples. The selected example or examples have been selected and described to explain the principles, practical applications of the examples, and to enable those skilled in the art to understand the disclosure of the different examples with various modifications suitable for the particular use contemplated.

Claims

1. A particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) comprising:

1. A porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) comprising a first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) and a second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214), wherein the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) is a porous filter substrate having a first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) and a second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214), and a porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) configured to filter gas flowing through the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) between the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214); a plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) coupled to said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and substantially parallel to one another along said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); a plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) in signal communication with the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) and configured to receive voltage signals from an input signal source (124, 224, 324, 624, 824, 1024, 1224); Including, The plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) are configured to couple to the porous filter substrate (11) in response to the plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) receiving the voltage signals from the input signal source (124, 224, 324, 624, 824, 1024, 1224). 1010, 1210) on at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214), the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) having a plurality of panels (238, 338, 638) and a plurality of accordion fold pleats (236, 336, 636) including a plurality of fold lines (240, 340, 640) between each of the plurality of panels (238, 338, 638); A particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200), wherein the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) extend across the plurality of panels (238, 338, 638) and the plurality of fold lines (240, 340, 640).

2. The plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720D, 820, 1020, 1220) are arranged to contact the first surface (112, 512, 712A, 712D, 812, 1012, 1212) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and the porous filter The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) of claim 1 , wherein the particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) is bonded to the second surface (114, 514, 714A, 714D, 814, 1014, 1214) of a substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210).

3. 3. The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) of claim 1 or 2, wherein the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 820, 1020, 1220) comprises a plurality of conductive fibers woven into the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 810, 1010, 1210).

4. The plurality of conductors (120, 220, 320, 420, 520, 620, 720C, 720D, 820, 1020, 1220) are formed on the first surface (112, 512, 712C, 712D, 812, 1012, 1212) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710C, 710D, 810, 1010, 1210) or on the porous filter substrate (110, 21 3. The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) according to claim 1 or 2, comprising a conductive material printed on at least one of the second surfaces (114, 514, 714C, 714D, 814, 1014, 1214) of the first surface (114, 514, 714C, 714D, 814, 1014, 1214).

5. the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) extend in a first direction (242, 342) along the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) is configured such that an electric field is applied along at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) in the first direction.

5. The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) of claim 1, further comprising the input signal source (124, 224, 324, 624, 824, 1024, 1224) configured to generate the voltage signal to form a traveling wave traveling in a second direction (244, 344) transverse to the first direction (242, 342).

6. The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) according to any one of claims 1 to 5, further comprising the input signal source (124, 224, 324, 624, 824, 1024, 1224) configured to generate the voltage signal such that the electric field forms a standing wave on at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214).

7. a sensor (134, 834, 1034, 1234) configured to measure the amount of particulates on the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); a controller (128, 828, 1028, 1228) in communication with said sensor (134, 834, 1034, 1234) and said input signal source (124, 224, 324, 624, 824, 1024, 1224), receiving a sensor signal from the sensor (134, 834, 1034, 1234) indicative of an amount of particulates on the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); determining a value of an electrical parameter of the voltage signal based on the quantity of particulates indicated by the sensor signal; and the controller (128, 828, 1028, 1228) configured to cause the input signal source (124, 224, 324, 624, 824, 1024, 1224) to provide the voltage signals having the electrical parameters having the values ​​to the plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222); The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) according to any one of claims 1 to 6, comprising:

8. 8. The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) according to any one of claims 1 to 7, further comprising a particulate collection receptacle (126, 226, 826, 1026, 1226) around the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) configured to collect particulates removed from the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) by the electric field.

9. a frame (116, 216, 316, 416, 516, 616) coupled to and supporting the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) comprises a plurality of filter media (546A-546F) arranged in parallel panels between the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) and the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214); The plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) are disposed on the first surface (112, 512, 516, 518, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210). The particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) according to any one of claims 1 to 8, wherein the particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) is coupled to a filter material (546A) of the plurality of filter media (546A-546F) defining a filter medium (712A, 712B, 712C, 712D, 812, 1012, 1212).

10. A method for removing particulates from a particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200), comprising: receiving voltage signals from an input signal source (124, 224, 324, 624, 824, 1024, 1224) at a plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) of a particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200), the particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) including a porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and a plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) coupled to said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210), 1210) between a first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and a second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) are substantially parallel to one another along the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210), and the plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) are configured to filter gas flowing through the plurality of conductors (120, 220, 320, 420, 520, 620,receiving a voltage signal from the input signal source (124, 224, 324, 624, 824, 1024, 1224) in signal communication with the input signal source (124, 224, 324, 624, 824, 1020, 1220); generating an electric field on at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) using the voltage signal on the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220); removing particulates from at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) using the electric field; Including, the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) extend in a first direction (242, 342) along the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); generating said electric field using said voltage signals on said plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220); forming a traveling wave moving in a second direction (244, 344) transverse to the first direction (242, 342) along at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214); forming a standing wave at a first time with the electric field to separate the particulates from at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214); and forming the traveling wave at a second time after forming the standing wave to move the particles in the second direction (244, 344); A method comprising:

11. removing the particulates from at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) using the electric field; using said electric field to move said particles in said second direction (244, 344) towards a particle collection receptacle (126, 226, 826, 1026, 1226); and collecting said particles in said particle collection receptacle (126, 226, 826, 1026, 1226); The method of claim 10, comprising:

12. receiving the voltage signals from the input signal source (124, 224, 324, 624, 824, 1024, 1224) at the plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222); receiving a first voltage signal at the first time; and receiving a second voltage signal at the second time; Including, 12. The method of claim 10 or 11, wherein an electrical parameter of the first voltage signal has a value different from a value of an electrical parameter of the second voltage signal.

13. measuring the amount of particulates on the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) by a sensor (134, 834, 1034, 1234); determining, using a controller (128, 828, 1028, 1228), to remove said particulates from said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) based on the amount of particulates measured by said sensor (134, 834, 1034, 1234); providing the voltage signal from the input signal source (124, 224, 324, 624, 824, 1024, 1224) to the plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) in response to determining to remove the particulate from the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); The method of any one of claims 10 to 12, further comprising:

14. measuring the amount of particulates on the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) by a sensor (134, 834, 1034, 1234); receiving, by a controller (128, 828, 1028, 1228), a sensor (134, 834, 1034, 1234) signal from the sensor (134, 834, 1034, 1234) indicative of the amount of particulates on the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); determining a value of an electrical parameter of the voltage signal based on the quantity of particulates indicated by the sensor (134, 834, 1034, 1234) signal; providing said voltage signals having said electrical parameters having said values ​​to said plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) by said input signal source (124, 224, 324, 624, 824, 1024, 1224); The method of any one of claims 10 to 13, further comprising:

15. A method for removing particulates from a particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200), comprising: receiving voltage signals from an input signal source (124, 224, 324, 624, 824, 1024, 1224) at a plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) of a particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200), the particulate filter (100, 200, 300, 400, 500, 600, 800, 900, 1000, 1100, 1200) including a porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and a plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) coupled to said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210), 1210) between a first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and a second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) are substantially parallel to one another along the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210), and the plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) are configured to filter gas flowing through the plurality of conductors (120, 220, 320, 420, 520, 620,receiving a voltage signal from the input signal source (124, 224, 324, 624, 824, 1024, 1224) in signal communication with the input signal source (124, 224, 324, 624, 824, 1020, 1220); generating an electric field on at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) using the voltage signal on the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220); removing particulates from at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) using the electric field; The first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) and the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, filtering gas flowing through said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) between said second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) of said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); adjusting a shape of said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) from a first shape to a second shape using an actuator (648, 848, 1048, 1248); Including, filtering gas flowing through the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) includes filtering gas flowing through the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) while the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) is in the first shape; Removing the particulates from at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) using the electric field comprises removing the particulates from the porous filter substrate (110, 210, 310, 410, 510, 610, 710, 1214) using the electric field. removing the particulate from at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) while the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) is in the second shape.

16. 1. A method of making a filter, comprising the steps of: Bonding a porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) to a frame (116, 216, 316, 416, 516, 616), comprising: 810, 1010, 1210) includes a first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) and a second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214), and the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 71 0C, 710D, 810, 1010, 1210) between the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) and the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214) of the porous filter substrate (110, 210, 310, 410, 510, 610, 710C, 710D, 810, 1010, 1210). coupling said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) to a frame (116, 216, 316, 416, 516, 616), said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) configured to filter gas flowing through said porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210); A plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) are generally parallel to one another along the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210). and coupling the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) to the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) such that forming a plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) in signal communication with said plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) and configured to receive a voltage signal from an input signal source (124, 224, 324, 624, 824, 1024, 1224); Including, The plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) are configured to couple to the porous filter substrate (11) in response to the plurality of input nodes (122, 222, 322, 622, 822, 1022, 1222) receiving the voltage signals from the input signal source (124, 224, 324, 624, 824, 1024, 1224). 1010, 1210) on at least one of the first surface (112, 512, 712A, 712B, 712C, 712D, 812, 1012, 1212) or the second surface (114, 514, 714A, 714B, 714C, 714D, 814, 1014, 1214), the porous filter substrate (110, 210, 310, 410, 510, 610, 710A, 710B, 710C, 710D, 810, 1010, 1210) having a plurality of panels (238, 338, 638) and a plurality of accordion fold pleats (236, 336, 636) including a plurality of fold lines (240, 340, 640) between each of the plurality of panels (238, 338, 638); the plurality of conductors (120, 220, 320, 420, 520, 620, 720A, 720B, 720C, 720D, 820, 1020, 1220) extending across the plurality of panels (238, 338, 638) and the plurality of fold lines (240, 340, 640).

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