Electroporation based antimicrobial apparatus

Abstract

The present technology relates to an electroporation based antimicrobial apparatus The electroporation based antimicrobial apparatus includes a negative electrode and a positive electrode powered by an energy source, operatively coupled to an air inlet structure, such that upon applying 10 an external electric field across the negative electrode and the positive electrode, a lightning-rod effect is generated that causes permanent damage to outer structure of microbes passing along with air through the air inlet structure, thus achieving instant disinfection. The energy source includes a 15 respiration driven triboelectric Nanogenerator (R-TENG) for harvesting wasted biomechanical energy from the periodic motion of respiration. The R-TENG includes a pair of nanofiber films comprising a first nanofiber film composed of a tribopositive material and a second nanofiber film 20 composed of a tribonegative material. The tribopositive and tribonegative materials are with opposite polarity and the R-TENG serves as a filtration system concurrently. Most illustrative diagram:

Description

[0001] ELECTROPORATION BASED ANTIMICROBIAL APPARATUS

[0002] Field of Invention

[0003] The present technology relates to in-situ disinfecting face masks . More particularly, the present technology relates to electroporation based antimicrobial apparatus that operates based on triboelectric powered ad nanowire assisted electroporation .

[0004] Background of the invention

[0005] Currently, the outbreak of Coronavirus Disease-2019 (COVID- 19 ) has led to a global crisis , which creates an enormous impact to the international healthcare system. As an airborne disease , COVID-19 can spread through aerosol transmission, meaning that a person can be simply infected by j ust inhaling the virus-laden respiratory particles . Hence , the public is recommended or even forced to put on their face mask to control the spread in society, as it provides an ef fective barrier against respiratory droplets . Consequently, the importance and effectiveness of mas k wearing in controlling the spreading of airborne diseases has once again been reminded as the memory of several past pandemics such as the outbreak of Spanish flu in 1918 and severe acute respiratory syndrome ( SARS ) in 2002 has gradually faded with time . Before an effective vaccine is fully developed, controlling the spread of infection is crucial to minimize the impact of a newly emerging disease in various aspects such as health, economic, fiscal , and social . Additionally, wearing a personal protective equipment ( PPE ) especially face masks , is considered as the most convenient nonpharmaceutical strategy to break the chain of infection though it has some limitations . First , most of the commercialized face mas ks lack antimicrobial and self-disinfecting properties and are only capable of filtering respiratory particles . The droplets will accumulate on the surface of the face mask and the viruses can survive for hours or even a few days . Therefore , it is recommended to change our face mas k frequently. However , most of the consumers tend to discard their face mask without proper disinfection proces s which results in the increasing likelihood of secondary transmission . Furthermore , the high consumption rate and low reusability of polypropylene-based face masks has generated tremendous amount of plastic waste, which results in negative impact to the environment . As an outcome , there exists a demand for a face mask which can provide instant self-disinfection with longer lifespan .

[0006] In order to achieve self-disinf ection, several studies have been conducted to functionalize face masks through various methods . For example , photosensitizers were incorporated in facemas k as an antiviral agent , which absorb energy from visible light and transfer it to the surrounding oxygen under solar illumination . As a result , reactive oxygen species ( ROS ) can be generated, which is capable of inactivating bacteria and viruses rapidly by damaging their DNA and cellular protein . While for photothermal material such as graphene oxide , high local temperature under solar irradiation can lead to the denaturation of microbes . Both photosensitizers and photothermal material is capable for disinfecting face masks , however their performance is mainly constrained by the availability of solar energy . In addition, electrothermal graphene-modified mas k has been proposed, which can generate a temperature over 80 ° C under 3 V voltage rapidly without the constraints of weather . However, a specific DC power supply is required for the charging procedure , which limits its practical application in certain areas . Therefore , a technology which includes a disinfection method without the constraints by weather and a portable energy harvester is required to overcome the abovementioned problems .

[0007] Summary of the Invention The present technology relates to a technology for disinfecting air instantly by damaging the outer structure of pathogens such as viruses , bacteria, and fungi on the surface of an air inlet structure through nanowire-assisted electroporation . In an embodiment , electroporation based antimicrobial apparatus is disclosed that is powered by a respiration-driven triboelectric nanogenerator (R-TENG) , which serves as an energy harvester and filtration system s imultaneously . The present technology is powered by a sustainable energy source , such as a respiration-driven triboelectric nanogenerator ( R-TENG) that harvests the wasted biomechanical energy sustainably from respiration for powering the electroporation unit and serves as a filtration system concurrently .

[0008] According to an aspect of the present technology, an electroporation based antimicrobial apparatus is provided . The electroporation based antimicrobial apparatus includes a negative electrode and a positive electrode powered by an energy source and operatively coupled to an air inlet structure , such that upon applying an external electric f ield across the negative electrode and the positive electrode , a lightning-rod effect is generated that causes a permanent damage to outer structure of microbes passing along with the air through the air inlet structure , thus achieving instant dis infection .

[0009] In an embodiment , the energy source includes a respiration- driven triboelectric nanogenerator ( R-TENG ) for harvesting wasted biomechanical energy from the periodic motion of respiration . The R-TENG also serves as a filtration system .

[0010] In an embodiment , the R-TENG includes a pair of nanofiber f ilms comprising a first nanofiber film composed of a tribopositive material and a second nanofiber film composed of a tribonegative material . The tribopositive and tribonegative materials are with opposite polarity and the R-TENG serves as a filtration system concurrently .

[0011] In an embodiment , polyvinyl alcohol ( PVA) and polyvinylidene f luoride ( PVDF ) are selected as the tribopositive and tribonegative materials .

[0012] In an embodiment, a first O-ring structure is disposed between the R-TENG and electroporation based antimicrobial apparatus , a second O-ring structure is disposed between the positive electrode and the negative electrode of the electroporation unit , and a third O-ring structure is disposed between the electroporation based antimicrobial apparatus and the air inlet structure, to avoid short circuit and to ensure all compartments are air-tight fitted .

[0013] In an embodiment , the R-TENG is designed to function solely by the dual-directional air flow from respiration without any additional mechanical parts .

[0014] In an embodiment , the electroporation based antimicrobial apparatus is sustainably powered by the R-TENG and the R- TENG is enclosed in an airtight sealed structure to ensure s low air flow through the nanofiber films .

[0015] In an embodiment , the pos itive electrode is made of metal mesh and metal hydroxide nanowires are grown on the surface of the copper mesh to form the negative electrode .

[0016] In an embodiment, the positive electrode is operatively coupled with the tribopositive material of R-TENG and the negative electrode is operatively coupled with the tribonegative material of R-TENG .

[0017] In an embodiment , at least one of the triboelectric materials is engineered to be dome-shaped for controlling the maximum displacement between the nanofiber membranes and achieving consistent co nt act -separation without any additional mechanical components as well as ensuring the air passing through the air inlet structure is fully filtered .

[0018] In an embodiment , a pressure drop across the triboelectric materials is engineered to be lower than the remaining fabric components of the air inlet structure to ensure the air flows only through the R-TENG .

[0019] In an embodiment , the negative electrode of the electroporation based antimicrobial apparatus is located at an inlet of the air inlet structure to negatively charge the microbes passing through the air inlet structure .

[0020] In an embodiment , the air inlet structure comprises : a face mask and an air filter .

[0021] The present technology provides R-TENG made of triboelectric material comprising any organic based nanofiber with a gap between the tribopositive and the tribonegative materials being large enough to generate a potential difference of not lower than 1 volt (V) . The electrode of both triboelectric layers comprises any conductive material which is attachable to the triboelectric layers such as aluminum or silver, while the material for the electroporation system may comprise any conductive mesh which has nanostructure with a high aspect ratio such as nanowires grown on it . In order to generate a high local electric field , the distance between the positive and negative electrodes of electroporation based antimicrobial apparatus should be small enough but not too close to avoid short circuits during the operation, the distance is approximately within the range of 0 . 2 millimeters (mm) to 1 mm. In order to prolong the lifespan and reduce the generated waste of the electroporation based antimicrobial apparatus , the R-TENG and the electroporation based antimicrobial apparatus are engineered to be enclosed in a single valve structure which is detachable and replaceable , meaning that only certain parts of the air inlet structure ( such as face mas k) are discarded rather than the whole product . Furthermore , the multiple valves comprising the electroporation based antimicrobial apparatus and the sustainable energy source ( such as for example R- TENG ) can be integrated with commercialized face mas ks such as silicone oxygen mas k, N95 respirator , gas mas k, a fullface respirator , and the like .

[0022] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conj unction with the following description and the accompanying drawings . It should be understood, however , that the following descriptions , while indicating preferred embodiments and numerous specific details thereof , are given by way of illustration and not of limitation . Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof , and the embodiments herein include all such modifications .

[0023] Brief Description of the Drawings

[0024] Other obj ects , features , and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings . In the drawings , wherein like reference numerals denote corresponding parts throughout the several views :

[0025] FIGURE 1A depicts a front perspective view of electroporation based antimicrobial apparatus operatively coupled to a face mask, in accordance with an embodiment .

[0026] FIGURE IB depicts an isometric view of the electroporation based antimicrobial apparatus operatively coupled to the face mask, in accordance with an embodiment .

[0027] FIGURE 1C depicts a side-perspective view of electroporation based antimicrobial apparatus operatively coupled to the face mask, in accordance with an embodiment . FIGURE 2A depicts an exploded view of the electroporation based antimicrobial apparatus , in accordance with an embodiment .

[0028] FIGURES 2B-2C depict exploded views of the electroporation based antimicrobial apparatus operatively coupled to a face mask, in accordance with an embodiment .

[0029] FIGURE 3 depicts a periodic motion of R-TENG through respiration, in accordance with an embodiment .

[0030] Detailed Description of the Preferred Embodiments

[0031] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention . However, it will be understood by those of ordinary s kill in the art that the invention may be practiced without these specific details . In other instances , well-known methods , procedures and / or components have not been described in detail so as not to obscure the invention . Reference will now be made in detail to the preferred embodiments of the present technology, examples of which are illustrated in the accompanying drawings . Various embodiments of the present technology provide a system for disinfecting air instantly by damaging the outer structure of pathogens such as viruses , bacteria, and fungi on the surface of an air inlet structure through nanowire- assisted electroporation system. In an embodiment, the present technology provides an electroporation based antimicrobial apparatus that operates based on electroporation-based disinfection and is powered by a respiration-driven triboelectric nanogenerator ( R-TENG) , which serves as an energy harvester and filtration system s imultaneously . The present technology provides a respiration-driven electroporation based antimicrobial apparatus powered by a sustainable energy source , such as for example a respiration-driven triboelectric nanogenerator ( R-TENG) that harvests the wasted biomechanical energy sustainably from respiration for powering the electroporation and also serves as a filtration system concurrently . In several other embodiments , other energy sources such as , for example, batteries , piezo electric effect-based energy sources , solar energy sources , and the like may be used .

[0032] According to various aspects , the triboelectric nanogenerator or so-called TENG is a technology which is capable of converting ambient mechanical energy into useful electricity through the coupling effect of triboelectrification and electrostatic induction . Triboelectrification is a process in which a material becomes electrically charged after it is contacted with another material with opposite polarity . Generally, a chemical bond which is known as adhesion is formed between some regions of the contacted surface . The potential difference between the two surfaces will serve as the driving force for charges such as free electrons or ions to move from one material to another until an equilibrium state of their electrochemical potential is achieved . When two previously contacted surfaces are separated, triboelectric charges will be produced on the surfaces as some of the bonded atoms will have the tendency to donate or accept extra electrons . Thereby resulting in the triboelectric charges which act as the driving force for the electrons within the electrodes to flow through an external circuit for balancing the potential difference . Hence , electricity is generated from the movement of free electrons which has the capability of powering up the electroporation based antimicrobial apparatus .

[0033] During respiration a periodic force can be exerted on a face mask through the exhalation and inhalation of air that creates an identical motion of a contact-separation mode TENG . By utilizing the dual-directional air flow from breathing as the driven force of TENG, the R-TENG of the present technology is engineered . In an embodiment, a single direction air flow is utilized when the one direction air valve is installed for the mas k . In an embodiment , in order to integrate the R-TENG into a face mas k, nanofiber films that are breathable , f lexible , and capable of filtering air are selected as triboelectric materials . In one or more embodiments , the R-TENG is designed to function solely by the dual-directional air flow from respiration without any additional mechanical parts .

[0034] FIGURE 1A depicts a front view of electroporation based antimicrobial apparatus operatively coupled to a face mask 100 , in accordance with an embodiment . FIGURE IB depicts an isometric view of the electroporation based antimicrobial apparatus 100 in isometric view, in accordance with an embodiment . FIGURE 1C depicts a side-view of the electroporation based antimicrobial apparatus 100 , in accordance with an embodiment .

[0035] FIGURE 2A depicts an exploded view of the electroporation based antimicrobial apparatus 100 , in accordance with an embodiment . FIGURES 2B-2C depict exploded views of the electroporation based antimicrobial apparatus 100 operatively coupled with a face mask 203 , in accordance with an exemplary scenario . In an embodiment, the electroporation based antimicrobial apparatus 100 is powered by an energy source 202 operatively coupled to an air input strcuture203 . The electroporation based antimicrobial apparatus 100 includes a negative electrode 204a and a positive electrode 204b powered by the energy source 202 . Upon applying an external electric field across the negative electrode 204a and the positive electrode 204b, a lightning-rod ef fect is generated that causes permanent damage to the outer structure of microbes in the air passing through the air input structure 203 , thus achieving instant disinfection . In an embodiment , the energy source 202 comprises a respiration driven triboelectric nanogenerator ( R-TENG ) for harvesting wasted biomechanical energy from the periodic motion of respiration, while the air input structure is a face mas k where the R-TENG 202 also serves as a filtration system. In an embodiment, the R-TENG 202 comprises a pair of nanofiber f ilms comprising a first nanofiber film 202a composed of a tribopositive material and a second nanofiber film 202b composed of a tribonegative material, such that the tribopositive and tribonegative materials are with opposite polarity. The R-TENG 202 serves as a filtration system concurrently . In an embodiment , polyvinyl alcohol ( PVA) and polyvinylidene fluoride ( PVDF) are selected as the tribopositive and tribonegative materials . In some other embodiments , any other known tribopositive and tribonegative materials can be used . In an embodiment , the R-TENG 202 is designed to function solely by the dual-directional air flow from respiration without any additional mechanical parts . In an embodiment , a first O-ring structure 210a is disposed between the R-TENG and electroporation based antimicrobial apparatus 100 , a second O-ring structure 210b is disposed between the positive electrode and the negative electrode of the electroporation based antimicrobial apparatus 100 and a third O-ring structure 210c is disposed between the electroporation based antimicrobial apparatus 100 and air input structure 208 ( such as for example , a face maskj s , to avoid short circuit and to ensure all compartments are airtight fit . In an embodiment , the electroporation based antimicrobial apparatus 100 is sustainably powered by the R- TENG 202 and the R-TENG 202 is enclosed in an airtight sealed structure to ensure slow airflow through the nanofiber films . In an embodiment , the positive electrode 204b is made of a metal mesh ( such as , copper ) with a pore s ize of about 50 to 200 pm and metal hydroxide nanowires ( such as copper hydroxide nanowires ) are grown on the surface of the metal mesh to form the negative electrode 204a . The positive electrode 204b is operatively coupled with the tribopositive material 202a of R-TENG and the negative electrode 204a is operatively coupled with the tribonegative material 202b of R-TENG 202 . In an embodiment , at least one of the triboelectric materials ( 202a and 202b ) is engineered to be dome-shaped for controlling the maximum displacement between the nanofiber membranes 202a / b and achieving consistent contact-separation without any additional mechanical components as well as ensuring the air will be fully filtered . In an embodiment , a pressure drop across the triboelectric materials 202a / b is engineered to be lower than the remaining fabric components of the face mask to ensure the air will only flow through the R-TENG 202 . The triboelectric materials 202a / b are parallelly aligned to each other . In several other embodiments , at least one of the triboelectric materials ( 202a and 202b ) is engineered to be of shapes other than dome shape .

[0036] When external electric field is applied , the lightning-rod effect causes the electric field strength at the tip of copper nanowires to be enhanced manifold with a very low driving voltage of about IV, which is sufficient to cause permanent damage to the outer structure of microbes , thus achieving instant disinfection within a second . As shown in Figure 2B , the negative electrode 204a is located at the inlet of the face mas k 208 and negatively charges the microbes that have passed through the face mask 203 . By charging the incoming microbes , the disinfection efficiency can be further improved as more microbes will be attracted to the positive electrode 204b with copper nanowires grown on it .

[0037] In an embodiment , the R-TENG 202 is capable of harvesting wasted biomechanical energy from the periodic motion of respiration to power the electroporation unit 204 sustainably and also serves as a filter simultaneously, that can purify ambient air for the user . In an embodiment , the tribopositive and tribonegative materials of the R-TENG 202 are fabricated through an electrospinning process to obtain nanofiber f ilm, which is breathable , flexible , and capable of filtering air . Due to their extremely small diameter in the nanoscale and the generated surface charges from the periodic contact-separation motion, it provides better f iltration efficiency than microfibers while the enhanced surface area by the nanofibers further improves the electrical output of R-TENG 202 while also improving the disinfection performance by the electroporation based antimicrobial apparatus 100 . The present technology is capable of achieving instant self-disinfection by damaging the outer structure of pathogens such as viruses , bacteria, and fungi on the surface of the filter through nanowire assisted electroporation as well as filtering ambient air s imultaneously .

[0038] FIGURE 3 depicts a periodic motion of R-TENG 202 through respiration, in accordance with an embodiment . During respiration, a periodic force is exerted on the face mask 203 through the exhalation 306 and inhalation 304 of air as shown in FIGURE 3 , which creates an identical motion of a contact-separation mode of R-TENG 202 . By utilizing the dual-directional air flow 302 from breathing as the driven force of R-TENG 202 , the R-TENG 202 is engineered in the present technology . In order to integrate the R-TENG 202 into the face mas k 203 , nanofiber films that are breathable , f lexible , and capable of filtering air are selected as the triboelectric materials . In one or more embodiments , the R- TENG 202 is designed to function solely by the dualdirectional air flow 302 from respiration without any additional mechanical parts .

[0039] The separation and the maximum displacement between both triboelectric layers are crucial to achieving stable electrical output , hence a consistent contact separation is necessary . In addition, the R-TENG 202 also serves as a f iltration system concurrently, that requires an airtight sealed structure around it to ensure air will solely flow through the nanofiber membranes . In order to achieve the abovementioned specifications , one of the nanofiber films is engineered to be dome-shaped, such that a maximum displacement between the nanofiber membranes can be controlled, for achieving consistent contact-separation without any additional mechanical components as well as ensuring that the air is fully filtered . Besides , the pressure drop across the nanofiber films is engineered to be lower than the remaining fabric components of the face mas k 100 to further ensure that the air will only flow through the R-TENG 202 .

[0040] According to an embodiment , the incorporation of antiviral agents such as nano-s caled metals , salts , photosensitizers and photothermal material is capable of disinfecting face masks effectively . However, instant disinfection within seconds is unachievable , as few minutes is required for the reaction among ROS and microbes , as well as generating sufficient heat under sun irradiation . Without instant disinfection, the trapped microbes within a face mas k may become a potential source of secondary transmission if proper disposal procedure is not conducted . Therefore , electroporation which can eliminate microbes rapidly is utilized as a new disinfection method in the present technology. Instead of chemically inhibiting microbes , electroporation offers physical disinfection by damaging the outer structure of microbes instantly via strong local electric field . With the intention to generate extremely high local electric field of about 10 MV / m through low voltage supply, nanostructures with high aspect ratio such as nanowire or nanorod is required . When certain voltage is supplied, enhanced local electric field will be generated at the tip of the nanostructure through the lightning-rod effect . Consequently, when microbes come into contact with the surface , instant disinfection can be achieved via electroporation . In addition, the low airflow rate through respiration with a facemas k can further enhance the feasibility of this disinfection method, as the probability of microbes approaching the tip structure is further improved .

[0041] The present technology provides an electroporation based antimicrobial apparatus powered by an R-TENG made of triboelectric material comprising any organic-based nanofiber with a gap between the tribopositive and the tribonegative materials being large enough to generate a potential difference of not lower than 1 volt (V) . The electrodes of both triboelectric layers comprise any conductive material which is attachable to the triboelectric layers such as aluminum or silver, while the material for the electroporation based antimicrobial apparatus may comprise any conductive mesh which has nanostructure with high aspect ratio such as nanowires grown on it . In order to generate high local electric f ield, the distance between the positive and negative electrodes of electroporation based antimicrobial apparatus should be small enough but not too close to avoid short circuits during the operation, the distance is approximately within the range of 0 . 2 millimeters (mm) to 1 mm . In order to prolong the lifespan and reduce the generated waste of electroporation based antimicrobial apparatus , the R-TENG and the electroporation based antimicrobial apparatus are engineered to be enclosed in a single valve structure which is detachable and replaceable , meaning that only certain parts of the face mask are discarded rather than the whole product . Furthermore , the multiple valves ( comprising the electroporation system and the sustainable energy source ( such as for example R-TENG ) can be integrated with commercialized face mas ks such as silicone oxygen mask, N95 respirator, gas mas k, a full-face respirator , and the like .

[0042] As will be readily apparent to those s killed in the art , the present technology may easily be produced in other specific forms without departing from its essential characteristics . The present embodiments are , therefore , to be considered as merely illustrative and not restrictive , the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come within therefore intended to be embraced therein .

Claims

CLAIMS1 . A electroporation based antimicrobial apparatus comprising : a negative electrode and a pos itive electrode powered by an energy source and operatively coupled to an air inlet structure , wherein upon applying an external electric field across the negative electrode and the positive electrode , a lightning-rod effect is generated that causes permanent damage to the outer structure of microbes passing along with air through the air inlet structure , thus achieving instant disinfection of the air passing through the air inlet structure .2 . The electroporation based antimicrobial apparatus of claim 1 , wherein the energy source comprises a respiration driven triboelectric Nanogenerator ( R-TENG ) for harvesting wasted biomechanical energy from the periodic motion of respiration, wherein R-TENG also serves as a filtration system.3 . The electroporation based antimicrobial apparatus of claim 1 , wherein the R-TENG comprises a pair of nanofiber films comprising a first nanofiber f ilm composed of a tribopositive material and a second nanofiber film composed of a tribonegative material , wherein the tribopositive and tribonegative materials are with opposite polarity, and wherein the R-TENG serves as a filtration system concurrently .4 . The electroporation based antimicrobial apparatus of claim 3 , wherein polyvinyl alcohol ( PVA) andpolyvinylidene fluoride ( PVDF ) are selected as the tribopositive and tribonegative materials .5 . The electroporation based antimicrobial apparatus of claim 3 , wherein a first O-ring structure is disposed between the R-TENG and the electroporation unit , a second O-ring structure is disposed between the positive electrode and the negative electrode of the electroporation unit , and a third O-ring structure is disposed between the electroporation unit and a face mask cover, to avoid short circuit and to ensure all compartments are air-tight fit .6 . The electroporation based antimicrobial apparatus of claim 3 , wherein the R-TENG is enclosed in an airtight sealed structure to ensure slow airflow through the nanofiber films .7 . The electroporation based antimicrobial apparatus of claim 1 , wherein the positive electrode is made of metal mesh and wherein metal nanowires are grown on the surface of the metal mesh to form the negative electrode .8 . The electroporation based antimicrobial apparatus of claim 2 , wherein the positive electrode is operatively coupled with the tribopositive material of R-TENG and the negative electrode is operatively coupled with the tribonegative material of R-TENG .9 . The electroporation based antimicrobial apparatus of claim 2 , wherein at least one of : the triboelectric materials is engineered to be dome-shaped forcontrolling the maximum displacement between the nanofiber membranes and achieving consistent contactseparation without any additional mechanical components as well as ensuring the air will be fully filtered .10 . The electroporation based antimicrobial apparatus of claim 1 , wherein a pressure drop across the triboelectric materials is engineered to be lower than the remaining fabric components of the face mask to ensure the air will only flow through the R-TENG .11 . The electroporation based antimicrobial apparatus of claim 1 , wherein the negative electrode is located at the inlet of the face mask to negatively charge the microbes pas sed through the face mas k .12 . The electroporation based antimicrobial apparatus of claim 1 , wherein the air inlet structure comprises : a face mask and an air filter .

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