Patent ID: 12218489

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. The illustrative embodiments described in the detailed description, drawings and claims are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the spirit or scope of the subject matter presented herein. Unless specified otherwise, the terms “comprising,” “comprise,” “including” and “include” used herein, and grammatical variants thereof, are intended to represent “open” or “inclusive” language such that they include recited elements but also permit inclusion of additional, un-recited elements. As used herein, the software and hardware of a “server” may be implemented within: a single stand-alone computer, a stand-alone server, multiple dedicated servers, and/or a virtual server running on a larger network of servers and/or a cloud-based service.

FIG.1is a block diagram representing an exposed electrode10with an integrated electronics module22and a conductive base12in an embodiment of the invention. The conductive base12is located between a mat surface11and an insulative surface14. The mat surface11is comprised of intertwined individual fibres. As illustrated inFIG.1, the proximate ends of the intertwined individual fibres are embedded inside the conductive base12; the distal ends of the intertwined individual fibres extend toward the mat surface11(see below for examples of alternative electrical connection means between the intertwined individual fibres and the electronics module22). The exposed electrode10includes an insulative perimeter15. The electronics module22is in electrical connection to the power supply21. The electronics module22is in electrical connection to an electrical connection point13rivet piercing the conductive base12.

InFIG.1, the possible user contact with the mat surface11is depicted at an extended finger16. The mat surface11has a minimum mean resistance of RMIN, as measured during a discharge event between the output port22C of the electronics module22and a measurement probe, the measurement probe tipped with a polished stainless steel sphere having a diameter of twenty millimetres, where:

RMIN=VMAXITH;(Equation⁢1)andITHis⁢a⁢capacitive⁢current⁢discharge⁢detection⁢threshold.

Under Equation 1, if the maximum preset negative voltage of VMAXis −20 kV and the capacitive current discharge detection threshold is 2 mA, then the calculated minimum mean resistance of RMINwould be 10 ma Maximum preset negative voltage of VMAXvalues of −40 kV, −60 kV, and −80 kV result in the minimum mean resistance of RMINcalculations of 20 MΩ, 30 MΩ, and 40 MΩ, respectively, if the capacitive current discharge detection threshold is 2 mA. As −20 kV is one of the more optimal voltages for the maximum preset negative voltage of VMAXand −80 kV is one of the highest likely voltages for the maximum negative preset voltage of VMAX, a preferable range for minimum mean resistance of RMINis from 10 MΩ to 40 MΩ, if the capacitive current discharge detection threshold is 2 mA.

For some low voltage exposed electrode negative air ion device embodiments, a lower maximum preset negative voltage of VMAXcould be set in the range of −3 kV to −20 kV, resulting in an acceptable range for minimum mean resistance of RMINfrom 1.5 MΩ to 10 MΩ, if the capacitive current discharge detection threshold is 2 mA. The lowest practical value for the maximum preset negative voltage of VMAXabout −3 kV, as below this voltage threshold there is very little corona discharge. SeeFIGS.8and9for experimental data taken at −7 kV and −20 kV for the maximum preset negative voltage of Vim.

Higher voltages values for maximum preset negative voltage of VMAXrequire increasingly larger creepage and clearance distances in the design of the exposed electrode10. Hence higher values of the maximum preset negative voltage of VMAXrequire a more bulky design for the exposed electrode10without changing its basic functionality. For many indoor installations, an upper limit of about −40 kV is preferable due to practical limitations in creepage and clearance distances.

For each of these values of the maximum preset negative voltage of VMAX, the invention prevents user discomfort from any electrical discharge when the exposed electrode negative air ion device properly pairs a maximum preset voltage of VMAXrange to the minimum mean resistance of RA/HA/of the mat surface11, according to Equation 1.

While under most circumstances a capacitive current discharge tends to affect the human body more like a direct current, some users' detection of a capacitive current discharge may be more akin to the users' detection of an alternating current. An alternating current of 0.5 mA is near or at the detection threshold for alternating currents of frequencies in the range of 15 to 100 Hz, while a direct current does not approach the detection threshold until around 2.0 mA. Thus for added protection of the user, the capacitive current discharge detection threshold could be set at 0.5 mA. Using a capacitive current discharge detection threshold of 0.5 mA, the minimum mean resistance of RMINshould be increased fourfold. E.g., under Equation 1, the maximum preset negative voltage of VMAXvalues of −3 kV, 20 kV and −40 kV result in the minimum mean resistance of R MIN calculations of 6 MΩ, 40 MΩ, and 80 MΩ, respectively if using a capacitive current discharge detection threshold of 0.5 mA.

The minimum mean resistance of RMIN, as defined above in Equation 1, is measured during a discharge event, sometimes referred to as an electric shock. A discharge event is an abrupt electrical discharge, such as from the mat surface11to an extended finger16, that occurs when a sufficiently high electric field creates an ionized, electrically conductive channel through the normally-insulating air. The measurement of the minimum mean resistance of RMINduring a discharge event best mimics the intended technical benefit of the invention during operating conditions. E.g., if the resistance were measured outside of a discharge event, the resistance measured by the measurement probe would be far higher than during a discharge event.

For a given voltage, a measurement probe tipped with a sphere creates a lower magnitude electric field than a measurement probe with a sharp point. The measurement probe used to measure minimum mean resistance of RMINis tipped with a polished stainless steel sphere having a diameter of twenty millimetres to best approximate a user touching the mat surface11with an extended finger16. In practice, the sphere can be a stainless steel machine ball knob attached to the body of the measurement probe with an M5 screw.

The minimum mean resistance of RMINis a “mean” resistance, as variations in the mat surface11may result in higher or lower resistance measurements at various locations of the mat surface11. A minimum mean resistance of RMINof a rectangular mat surface11could be, for instance, the fifth highest resistance measured among a square grid of nine locations on the mat surface11, where the square grid has three rows and three columns. A minimum mean resistance of RMINof a spherical mat surface11could be, for instance, the third highest resistance measured among a first point at the sphere's pole opposite the electrical connection point13and four additional points along the equator of the sphere at 0°, 90°, 180°, and 270° (the electrical connection point13and the first point defining the axis of the sphere).

As depicted inFIG.1, the electrical connection point13employs a conductive rivet that pierces through the conductive base12. The conductive base12can be pierced with multiple conductive rivets at various locations of the conductive base12, wherein each conductive rivet is connected to the electronics module22via electrical wiring. Other electrical connection means such as conducting screws, flat surface electrodes, conductive epoxy, electrical wiring, or a combination thereof can also be employed at the one or more electrical connection points13.

As depicted inFIG.1, the proximate ends of the intertwined individual fibres are embedded within the conductive base12, however other methods of mounting the intertwined individual fibres on the conductive base12(such as with a conductive epoxy, heat treatment, weave, or mechanical pressure) are also possible. The mat surface11of the intertwined individual fibres can be either permanently attached to the conductive base12or the mat surface11can be replaceable.

As depicted inFIG.1, the electronics module22is integrated into the exposed electrode10, however the electronics module22can also be mounted outside the exposed electrode10. E.g., the exposed electrode10could be a replaceable unit that snaps into place on a mounted bracket housing one or more devices, where the mounting bracket includes the electronics module(s)22. Also, multiple exposed electrodes10could route to different output ports22C of a single electronics module22.

As depicted inFIG.1, the exposed electrode10includes a conductive base12and the negative voltage source23passes from the output port22C, to the conductive base12at an electrical connection point13, and the mat surface of intertwined individual fibres11. However, in other embodiments of the invention, the conductive base12is not included in the exposed electrode10; the negative voltage source23passes from the output port22C to the mat surface of intertwined individual fibres11at one or more electrical connection points13. In this embodiment, the intertwined individual fibres at the one or more electrical connection points13act as conductors to distribute the negative voltage source23across the mat surface11.

FIG.2is a block diagram representing the output of a negative voltage source23from an output port22C of the electronics module22to the conductive base12of the exposed electrode10in an embodiment of the invention. The electronics module22includes an input port22A in electrical connection to a power supply21and an output port22C in electrical connection to the conductive base12of an exposed electrode10(not shown). The electronics module22includes a negative voltage generator22B configured to produce a negative voltage source23with a maximum preset negative voltage of Vex.

As depicted inFIG.2, the electronics module22includes an IoT module22D with wireless communication capability. The IoT module22D can also employ wired powerline communication through the power supply's21wire connections. See the description ofFIG.5below for more details on the use of the IoT modules22D in the negative air ion panel system50.

As depicted inFIG.2, the negative voltage source23passes from the output port22C, of the electronics module22to the conductive base12. However, in other embodiments of the invention, the conductive base12is not included and the negative voltage source23passes from the output port22C to the mat surface of intertwined individual fibres11at one or more electrical connection points13. In this embodiment, the intertwined individual fibres at the one or more electrical connection points13act as conductors to distribute the negative voltage source23across the mat surface11.

FIG.3lists a series of equations 3-00 representing the derivation of an equation for the maximum permissible surface area AMAXof a single charged disk plate at a given voltage in an embodiment of the invention. In alternative embodiments of the invention, the user's detection of a shock can be eliminated by limiting the maximum capacitance of the exposed electrode10, given a maximum preset negative voltage. Capacitance is a function of the geometry of the capacitor. A single charged disk plate has a self-capacitance of 8ϵ0rDper Equation 3a ofFIG.3. The self-capacitance of a flat mat surface11of an exposed electrode10(such as a rectangular-shaped panel) can be roughly approximated by the self-capacitance of a single charged disk plate of identical surface area.

As discussed in the IEC60479 reference, the charge discharge detection threshold of a human is 0.4 μC. The maximum charge of a capacitor is its capacitance times the capacitor's voltage (here the maximum preset negative voltage of Vex). VMAXis, from experimental data, preferably about −20 kV (e.g., in the range of −18 kV to −22 kV) to efficiently create NAIs. Assuming a −20 kV Vex, then the approximate capacitance of a rectangular-shaped panel should be limited to 20 pF per Equation 2 ofFIG.3if the charge discharge detection threshold QTHis 0.4 μC. As derived in the equations ofFIG.3, the maximum surface area of a single charged disk plate AMAXis represented by Equations 3b to 3d.

Employing Equation 3c, the maximum surface area AMAXof a disk-shaped panel would be 0.25 square metres. E.g., to limit the maximum charge stored on the disk-shaped panel to 0.4 μC (the charge discharge detection threshold of a human) with a −20 kV VMAX, the capacitance must be limited to 20 pF by limiting the surface area of the panel to about 0.25 square metres. Note that the maximum surface area, per Equation 3d, is proportional to VMAX−2; if VMAXis doubled to −40 kV then the maximum surface of the maximum surface area of the mat surface11of a disk-shaped panel should be reduced by 75% (e.g., for the above example, from 0.25 square metres to 0.0625 square metres). The Equation 3c calculation for the self-capacitance of a disk-shaped panel can be used to approximate the maximum surface area AMAXof a rectangular-shaped panel mat surface11or any other mat surface11that is flat in shape. E.g., as used in this disclosure and the claims, the maximum surface area AMAXis used to approximate a maximum surface area for any type of flat surface (whether disk-shaped or rectangular-shaped).

FIG.4lists a series of equations 4-00 representing the derivation of an equation for the maximum permissible radius of a single charged sphere at a given voltage in an embodiment of the invention. As in the case of a rectangular-shaped panel geometry discussed above in regard toFIG.3, the user's detection of a shock can be eliminated by limiting the capacitance of a sphere-shaped exposed electrode10at a given maximum preset negative voltage. The self-capacitance of a sphere-shaped exposed electrode10can be roughly approximated by the self-capacitance of a single charged sphere. A single charged sphere has the self-capacitance of 4ϵ0rDper Equation 4a ofFIG.4.

Assuming a −20 kV Vex and a charge discharge detection threshold of 0.4 μC, the capacitance of an exposed electrode10should be limited to 20 pF per Equation 2 ofFIG.4. As derived in the equations ofFIG.4, the maximum radius of a single charged sphere is represented by Equation 4b. Employing Equation 4b, the maximum radius of the spherical electrode can be roughly approximated as 0.56 metres so as to limit the capacitance to 20 pF. Note that the maximum radius of the sphere, per Equation 4b, is proportional to VMAX−1; if VMAXis doubled to −40 kV then the maximum radius of a sphere-shaped panel is reduced by 50% to approximately 0.28 metres.

FIG.5is a block diagram representing a negative air ion panel system50in an embodiment of the invention. The system50includes a grid arrangement51on a wall with four columns and four rows of exposed electrodes10(see items1A to1D,2A to2D,3A to3D, and4A to4D) in an exposed environment56. The grid arrangement51is electrically connected to a power supply21.FIG.5illustrates an exposed environment56in which humans are present; in the exposed environment56the humans are not insulated or prevented from touching the mat surfaces11of the exposed electrodes10.

As illustrated inFIG.5, the exposed environment56also includes a gateway53with wireless data communication capability to a plurality of sensors52mounted in the exposed environment56. Though not illustrated inFIG.5, the gateway53can also connect wirelessly to the IoT modules22D of each device or via wired powerline communication. The gateway53is in data communication with a network54, and the network54of the system50is connected to an offsite server55. The offsite server55includes a parameter settings module55A, a sensor records module55B, and an analytics module55C.

FIG.6includes a diagram6-00identifying test data collection locations for the testing of various cylindrical samples61. The test data was collected variously at one metre or two metres from an outside center62of the cylindrical sample61at the identified angles of 45°, 90°, and 135° in the x-y plane parallel to the floor as illustrated in diagram6-00.

FIG.7A-7Care charts (7A-00,7B-00, and7C-00) documenting test data values experimentally collected for various cylindrical samples61of intertwined individual fibres wrapped around a cylindrical pole and electrically connected to a voltage pulse source. The test data summarized in the charts (7A-00,7B-00, and7C-00) represents average negative air ion readings over a sample time of about 10 seconds. The charts' test data are provided in units of 1,000 negative ions per cubic centimetre (1,000 NAI/cm3).

TheFIG.7Achart7A-00provides test data taken at one metre and at two metres from the outside center62of the cylindrical sample61, as illustrated in the diagram6-00ofFIG.6. TheFIG.7Bchart7B-00and theFIG.7Cchart7C-00provide test data taken at one metre from the outside center62of the cylindrical sample61, as illustrated in the diagram6-00ofFIG.6. The ambient NAI during the collection of test data was approximately 130 NAI/cm3. The test data represents the average negative ion emissions readings over a sample time of about 10 seconds. The maximum preset negative voltage for the set of negative voltage pulses was −20 kV.

The chart7A-00ofFIG.7Aprovides test data for a cylindrical coconut coir sample that has not been treated with a fire retardant and has not been treated with a water repellant. The chart7B-00ofFIG.7Bprovides test data for a cylindrical coconut coir sample that has been treated with a fire retardant. The chart7C-00ofFIG.7Cprovides test data for a cylindrical coconut coir sample that has been treated with a water repellant.

The chart7A-00ofFIG.7Ademonstrates the decrease in NAI concentration as a function of distance from the outside center62of the cylindrical sample61. A comparison of the test data of the three charts (7A-00,7B-00, and7C-00) indicates that: (i) NAI emissions for coconut coir fibres is about the same for untreated, fire retardant treated, and water repellant treated coconut coir; and (ii) whether wet or dry, coconut coir fibres emit about the same NAI concentrations.

FIG.8includes a diagram8-00identifying test data collection locations for the testing of circular samples81in an x-y plane parallel to the floor. The circular samples81were electrically connected to a voltage pulse source. The circular samples81of various fibre braids were: (i) approximately 20 centimetres in length; and (ii) wrapped around and attached to the equator area of a sphere-shaped ball82. The test data was collected as illustrated in diagram8-00: (i) at a radial distance of 5 cm from the braid at the identified angles of 90°, 180°, and 270°; and (ii) in the x-y plane parallel to the floor.

The chart9-00ofFIG.9documents test data values experimentally collected for various types of circular samples81for fibre braids. The length of each fibre braid was approximately 20 centimetres. The test data summarized in the chart9-00represents the average negative ion emissions readings over a sample time of about 10 seconds at a radial distance of 5 centimetres from the surface of each of the circular samples of fibre braid. The chart's test data is provided in units of 1,000 negative ions per cubic centimetre (1,000 NAI/cm3). The ambient NAI during the collection of test data was approximately 130 NAI/cm3. Test data was taken with the maximum preset negative voltage for the set of negative voltage pulses at −20 kV and separately at −7 kV. Sample braids included fibres from coconut coir, nettle (coarse), nettle (fine), pineapple, banana, jut, abaca, and hyacinth.

As documented in chart9-00, the test data documents that NM emissions significantly improved with the maximum preset negative voltage set at −20 kV, as contrasted with −7 kV. The test data also demonstrates that NAI emissions were generally consistent along at each angle tested in the x-y plane. Overall, coconut coir and coarse nettle braids tested better than the other fibre types. It is theorized that the spiky or furry nature of natural fibres such as coconut coir provides a high NAI emission efficacy over an extended surface area because the uneven surface and sharp end points of the individual fibres provide a large number of locations for high curvature geometric shapes, resulting in a large number of local electrical field maximums that separately facilitate corona discharge.

A first embodiment of the invention is an exposed electrode10negative air ion device, the device comprising: (a) an electronics module22including an input port22A, a negative voltage generator22B, and an output port22C; and (b) an exposed electrode the exposed electrode10including a mat surface11of intertwined individual fibres. The input port22A is configured to electrically receive a power supply21and electrically route the power supply21to the negative voltage generator22B. The negative voltage generator22B is configured to: (1) generate a negative voltage source from the power supply21; and (2) output the negative voltage source to the output port22C within a set of electrical parameters. The set of electrical parameters includes: (1) a maximum preset negative voltage of VAN; and (2) a maximum operating current, the maximum operating current set below or equal to a direct current detection threshold. The mat surface11of the exposed electrode10is directly or indirectly electrically connected to the output port22C of the electronics module22at one or more electrical connection points13. The mat surface11has a minimum mean resistance of RMIN, as measured during a discharge event between the output port22C of the electronics module22and a measurement probe, the measurement probe tipped with a polished stainless steel sphere having a diameter of twenty millimetres, where:

RMIN=VMAXITH;(Equation⁢1)andITHis⁢a⁢capacitive⁢current⁢discharge⁢detection⁢threshold.

In an alternate embodiment of the first embodiment of the invention, the mat surface11is flat in shape and has a maximum surface area of AMAX, where:

AMAX=π×(QTHVMAX×8⁢ϵ0)2;(Equation⁢3⁢d)QTHis⁢a⁢charge⁢discharge⁢detection⁢threshold;andϵ0is⁢permittivity⁢of⁢free⁢space.

The charge discharge detection threshold can be 0.4 μC.

In an alternate embodiment of the first embodiment of the invention, the mat surface11is spherical in shape and has a maximum radius of rMAX, where:

rMAX=QTHVMAX×4⁢ϵ0;(Equation⁢4⁢b)QTHis⁢a⁢charge⁢discharge⁢detection⁢threshold;andϵ0is⁢permittivity⁢of⁢free⁢space.

The charge discharge detection threshold can be 0.4 μC.

In an alternate embodiment of the first embodiment of the invention, the direct current detection threshold is 2.0 mA.

In an alternate embodiment of the first embodiment of the invention, the capacitive current discharge detection threshold is 2.0 mA.

In an alternate embodiment of the first embodiment of the invention, the minimum mean resistance of RMINis in the range of 10 MΩ to 40 MΩ. Note that the invention is not limited to the minimum mean resistance of RMINrange dictated by this alternative embodiment; the full minimum mean resistance of RMINrange is 1.5 MΩ to 80 MΩ.

In an alternate embodiment of the first embodiment of the invention, the intertwined individual fibres are comprised of at least one of coconut coir fibre, hyacinth fibre, jute fibre, abaca fibre, banana fibre, pineapple fibre, and nettle fibre. Note that the invention is not limited to the natural fibres listed in this alternative embodiment; alternative natural fibres can also be used with the invention, and, additionally, engineered polymer fibres may also be used with the invention.

In an alternate embodiment of the first embodiment of the invention, the intertwined individual fibres are comprised of flame retardant coconut coir fibres with: (a) a mean diameter in the range of 0.1 mm to 0.5 mm; and (b) a mean length in the range of 0.15 m to 0.28 m.

In an alternate embodiment of the first embodiment of the invention, the intertwined individual fibres are hygroscopic. Hygroscopicity of the natural fibres is an important characteristic of natural fibres because the water content of natural fibres is the primary conductive material of the fibre. Without this water within the fibre, natural fibres would be unsuitable for NAI generation because the resistance of the fibres would be excessively high. The main components of plant fibres are, in decreasing order of hygroscopicity: hemicellulose, cellulose, and lignin. By selecting fibres with different ratios of these three constituents, it is possible to tune the bulk resistivity of a fibrous mat surface11of an exposed electrode10for a particular humidity.

Additionally, hygroscopic fibres have the benefit of potentially reducing ozone emissions as water reacts with ozone to produce short live OH−radicals. Natural fibres have high levels of hygroscopicity. Certain engineered polymers fibres are also hygroscopic. Hygroscopic engineered polymer fibres include nylon, ABS, polycarbonate, cellulose, and poly(methyl methacrylate). Engineered polymer fibres can also be coated to increase their hygroscopicity (e.g., see Japanese Patent No. 3177719B2 entitled “Synthetic fiber with improved hygroscopicity” granted 18 Jun. 2001).

In an alternate embodiment of the first embodiment of the invention, the mat surface11of the exposed electrode10is at least one of: (a) a length of intertwined individual fibres wrapped around a spherical base or a cylindrical base; (b) a suspended rope; and (c) a rectangular mat.

In an alternate embodiment of the first embodiment of the invention, the maximum preset negative voltage of VMAXranges from −18 kV to −22 kV. Use of a maximum preset negative voltage in this range has the benefit of reducing the production of ozone ions while maintaining an effective generation of negative air ions. Note that the invention is not limited to the maximum preset negative voltage range dictated by this alternative embodiment; the full maximum preset negative voltage of VMAXranges from −3 kV to 80 kV.

In an alternate embodiment of the first embodiment of the invention, the electronics module22is incorporated into the exposed electrode10.

In an alternate embodiment of the first embodiment of the invention: (a) the exposed electrode10includes a conductive base12; (b) the mat surface11of intertwined individual fibres is mounted on the conductive base12; and (c) conductive base12is electrically connected to the output port22C of the electronics module22at one or more electrical connection points13. This embodiment can alternatively be configured such that: (a) the exposed electrode10includes an insulative perimeter15and an insulative surface14; and (b) the conductive base12is located between the mat surface11and the insulative surface14. This embodiment can also alternatively be configured such that the conductive base12comprises a carbon infused elastomer.

A second embodiment of the invention is a negative air ion panel system50comprising two or more of the device of the first embodiment of the invention and/or the alternative embodiments of the first embodiment of the invention.

In an alternative embodiment of the second embodiment of the invention, each of the mat surfaces11of the devices in the system50are configured in at least one of: (a) a grid arrangement51on a wall, a ceiling, or a floor of the exposed environment56; (b) a grouping of spheres or cylinders in the exposed environment56; and (c) a set of individual panel mountings in the exposed environment56. Note that use of the invention is not limited to the configurations listed in this alternative embodiment; non-limiting examples for configuration of the mat surfaces11include their mounting: (a) outdoors to trees, overhead covered walkways, bus shelters, lamp posts, street furniture, and advertising panels; and (b) indoors on cubicle walls, lamp shades, sun shades, and furniture sidings.

In an alternative embodiment of the second embodiment of the invention, the power supply21of each device is generated by a local solar panel.

In an alternative embodiment of the second embodiment of the invention, the system50further comprising a gateway53, a network54, and an offsite server55, wherein each electronics module22of the devices in the system50further includes an IoT module22D in data communication with the offsite server55through the gateway53and the network54. This embodiment can alternatively be configured such that: (a) the offsite server55further comprises a parameter settings module55A, the parameter settings module55A configured to store a latest set of electrical parameters for each device in the system50; (b) the IoT module22D of each device is configured for wired or wireless data communication to and from the parameter settings module55A of the offsite server via the gateway53and the network54; (c) the parameter settings module55A is configured to send each device the latest set of electrical parameters for the device; and (d) each device is configured to receive the latest set of electrical parameters for the device, via the IoT module22D of the device, from the parameter settings module55A. This embodiment can alternatively be configured such that: (a) the offsite server55further comprises a sensor records module55B; (b) the system50further comprises a plurality of sensors52mounted in the exposed environment56that are each in data communication with the sensor records module55B of the offsite server55via the gateway53and the network54; and (c) the sensors52include at least one of a temperature sensor52, a humidity sensor52, a motion sensor52; and a negative ion concentration sensor52. This embodiment can alternatively be configured such that: (a) the offsite server55further comprises an analytics module55C; and (b) the analytics module55C is configured to create a system50report detailing at least one of a history of selected sensor52data stored in the sensor records module55B and a summary of the latest set of electrical parameters for each device in the system50.

The primary technical solution of the invention maintaining current levels and/or charge discharge levels below the detection threshold. The maximum operating current is set below or equal to the direct current detection threshold by the electronics module22. The maximum capacitive current discharge is maintained below or equal to a capacitive current discharge detection threshold with: (i) the use of high resistance intertwined individual fibres on the mat surface11of the exposed electrode10that maintain at least a minimum mean resistance of R MIN over the mat surface11; and (ii) a maximum preset negative voltage that is matched to the minimum mean resistance of RMINof the mat surface11. In alternative embodiments, the maximum charge discharge can additionally be maintained below or equal to a charge discharge detection threshold by limiting the capacitance of a flat exposed electrode10via a limitation of the maximum surface area of AMAXor by limiting the capacitance of spherical exposed electrode10via the maximum radius of rMAX

The result of limiting these current and charge discharge characteristics is an exposed electrode10negative air ion device with an exposed electrode10that can be touched by a user in an exposed environment56without physical pain and/or discomfort from any current or charge discharge. This design permits continuous and safe operation of the exposed electrode negative air ion device in an exposed environment56, whether the device is a stand-alone consumer product or whether two or more of the devices are used in a system50. Exposed electrodes10can, for instance, be mounted in a grid arrangement51on a wall or ceiling of a high traffic area within a private or public space. Unlike the '993 design, a halting of the negative voltage source and a bleeding off of any capacitive charge residing on the exposed electrode10is not required due to the presence of user's in the vicinity of the exposed electrode10.

Additional technical solutions of the invention include quiet fan-less operation and seamless integration of the exposed electrodes10into an exposed environment56. The invention permits an unlimited number of individual panels in a grid arrangement51on a wall or ceiling for a distributed and sustained production of NAI.

The aesthetic properties of natural fibres further enhance the ability of the exposed electrodes10to be integrated into an exposed environment56. The consumer can select among panels of various colours and sizes to add to the decor and general ambience of a space. And, unlike house plants, mat surfaces11of natural fibres do not cause static shock to the touch and do not require regular watering. The preferred material for the invention, coconut coir, is a low cost renewable agricultural by-product with high NAI emission performance (seeFIGS.7and9) whether wet or dry, and whether treated or untreated.

Inclusion of the sensors52mounted in the exposed environment56and the optional IoT module22D in each electronics module22can additionally provide remote management of the system50. Sensors52can include temperature sensors, humidity sensors, and negative ion concentration sensors. In this manner, feedback from sensors52in the exposed environment56can be used to optimize the electrical parameters of the devices via an offsite server55.

The invention's mat surface11also enables an NAI design with low ozone emissions, especially for the preferred voltage range of −18 kV to −22 kV. The mat surface11has a large number of intertwined individual fibres. Each fibre has rough edges along its length and a sharp distal end creating a large number of locations which act as localized electrodes. With the multiple localized electrodes over the mat surface11, the maximum preset negative voltage can be reduced while maintaining a high level of NAI emission.

Hygroscopicity of the natural fibres enables sufficient conductivity of natural fibres for suitable NAI generation, as the water content of natural fibres is the primary conductive material of the fibre. Without this water within the fibre, natural fibres would be unsuitable for NAI generation because the resistance of the fibres would be excessively high. Ozone production is likely also reduced from the use of natural fibres as their inherent hygroscopic properties increases the amount of water available at the emitting electrode. Water reacts with ozone to produce short live OH−radicals, and in this process reduces the ozone concentration.

While various aspects and embodiments have been disclosed herein, it will be apparent that various other modifications and adaptations of the invention will be apparent to the person skilled in the art after reading the foregoing disclosure without departing from the spirit and scope of the invention and it is intended that all such modifications and adaptations come within the scope of the appended claims. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit of the invention being indicated by the appended claims.