Patent Application
20230296544
The present invention relates to real-time impedance spectroscopy using 2D transition metal dichalcogenide material-based chemical sensor systems and methods of making and using same.
Current sensor systems used to detect the level of gases are not as sensitive as desired they are typically limited to a gas ppm level for organic gases and inorganic gases including NO2, CO2, NH3, H2O, NO, isopropyl alcohol, methanol, ethanol, aniline, toluene, and napthalene. While certain sensors may be able to achieve a gas ppb sensitivity, the materials and equipment needed to implement such sensor systems are complex, expensive and time consuming to fabricate. Many of the gases that OSHA regulates must be detected and measured at low ppms. However, for practical use, a sensor system needs to be capable of detecting and measuring such gases at several orders of magnitude below such ppm levels. Thus, what is needed is an inexpensive, easy fabricate and use gas detection system.
Applicants recognized that the initial resistance of current flake material networks was too high for effective operation in a gas detection system. Such recognition led Applicants to develop an impedance approach to breakdown the resistance into multiple, measureable resistance components. Thus, a real time impedance can be used to measure the resistance of a flake network when exposed to a gas. This change in the resistance can now be used to determine the concentration of a gas of interest, in many cases, down to a parts per trillion level. Thus, gas concentrations can efficiently and effectively determined on a more accurate level and less expensively than before.
The present invention relates to real-time impedance spectroscopy using 2D transition metal dichalcogenide material-based chemical sensor systems and methods of making and using same. Impedance approach to breakdown the resistance into multiple, measureable resistance components is used in such system. Thus, a real time impedance can be used to measure the resistance of a flake network when exposed to a gas. This change in the resistance can now be used to determine the concentration of a gas of interest, in many cases, down to a parts per trillion level. Thus, gas concentrations can efficiently and effectively determined on a more accurate level and less expensively than before.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
Unless specifically stated otherwise, as used herein, the terms “a”, “an” and “the” mean “at least one”.
As used herein, the terms “include”, “includes” and “including” are meant to be non-limiting.
As used herein, the words “about,” “approximately,” or the like, when accompanying a numerical value, are to be construed as indicating a deviation as would be appreciated by one of ordinary skill in the art to operate satisfactorily for an intended purpose.
As used herein, the words “and/or” means, when referring to embodiments (for example an embodiment having elements A and/or B) that the embodiment may have element A alone, element B alone, or elements A and B taken together.
Unless otherwise noted, all component or composition levels are in reference to the active portion of that component or composition, and are exclusive of impurities, for example, residual solvents or by-products, which may be present in commercially available sources of such components or compositions.
All percentages and ratios are calculated by weight unless otherwise indicated. All percentages and ratios are calculated based on the total composition unless otherwise indicated.
It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.
For purposes of this specification, headings are not considered paragraphs and thus this paragraph is paragraph thirty-six of the present specification. The individual number of each paragraph above and below this paragraph can be determined by reference to this paragraph's number. In this paragraph thirty-six, Applicants disclose a sensor system comprising:
Applicants disclose a sensor system according to paragraph thirty-six wherein:
Applicants disclose a sensor system according to paragraphs thirty-six through thirty-seven wherein said plurality transition metal dichalcogenide nanoflakes have thickness of from about 0.3 nm to about 10,000 nm, preferably said plurality transition metal dichalcogenide nanoflakes have thickness of from about 1 nm to about 1000 nm, more preferably said plurality transition metal dichalcogenide nanoflakes have thickness of from about 3 nm to about 100.
Suitable transition metal dichalcogenide (TMD) nanoflakes comprising of a transition metal and sulfur, selenium, or tellurium can be obtained from Millipore Sigma (400 Summit Drive, Burlington, Mass. 01803 USA)
For purposes of this specification, headings are not considered paragraphs and thus this paragraph is paragraph forty of the present specification. The individual number of each paragraph above and below this paragraph can be determined by reference to this paragraph's number. In this paragraph forty, Applicants disclose a method of determining a gas concentration comprising:
Applicants disclose a method according to paragraph forty wherein said gas is selected from the group consisting of organic gases, inorganic gases and mixtures thereof, preferably said gas is selected from the group consisting of Water, Ammonia, Benzyl chloride, Carbon monoxide, Carbon dioxide, Carbon disulfide, 1,4-dioxane, Hydrogen sulfide, Chlorine, Chlorine dioxide, Ethylene oxide, Formaldehyde, Hydrogen cyanide, Hydrogen sulfide, Methyl mercaptan, Methacrolein, Acrolein, Diisopropylamine, Tripropylamine, Napthanlene, Nitric oxide, Nitrogen dioxide, Oxygen, Phosphine, Sulfur dioxide, Isopropyl Alcohol, Methanol, Ethanol, Anile and Toluene and mixtures thereof, more preferably said gas is selected from the group consisting of Water, Ammonia, Carbon dioxide, Carbon disulfide, Chlorine, Methacrolein, Acrolein, Napthanlene, Nitric oxide, Nitrogen dioxide, Oxygen, Sulfur dioxide, Isopropyl Alcohol, Methanol, Ethanol and mixtures thereof, most preferably said gas is selected from the group consisting of Water, Ammonia, Carbon dioxide, Napthanlene, Nitric oxide, Nitrogen dioxide, Isopropyl Alcohol, Methanol, Ethanol and mixtures thereof.
Applicants disclose the method of Paragraphs forty through forty-one wherein said gas concentration is from about 1 part per trillion (ppt) to about a million parts per million, preferably said gas concentration is from about 50 ppt to about 100,000 ppm, more preferably said gas concentration is from about 100 ppt to about 10,000, most preferably said gas concentration is from about 1 ppb to about 1000 ppm.
The following examples illustrate particular properties and advantages of some of the embodiments of the present invention. Furthermore, these are examples of reduction to practice of the present invention and confirmation that the principles described in the present invention are therefore valid but should not be construed as in any way limiting the scope of the invention.
Example 1: Thin film nanoflake MoS2 sensor on glass substrate. Few-layer MoS2 nanoflakes were exfoliated from bulk powders using the redox exfoliation process and dispersed in acetonitrile. The dispersions contain of few-layer MoS2 flakes with an average flake diameter of approximately 100 nm and a thickness of 2-8 layers (
Example 2: WSe2 nanoflake sensor on flexible kapton substrate and wearable platform. WSe2 nanoflakes were drop casted to a thickness of 1000 nm onto a kapton sheet with interdigitated molybdenum contacts and a device spacing of 10 microns. The nanoflake device is connected to a potentiaostat that is integrated onto a wearable flexible electronics platform. The wearable system individually measures three different frequencies and applies an algorithm to measure humidity in the atmosphere with high precision.
Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While the present invention has been illustrated by a description of one or more embodiments thereof and while these embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and process, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope of the general inventive concept.
The present application claims priority to U.S. Provisional Application Ser. No. 63/321,805 filed Mar. 21, 2022, the contents of both such priority documents being hereby incorporated by reference in their entry.
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
| Number | Date | Country | |
|---|---|---|---|
| 63321805 | Mar 2022 | US |
