Patent Description:
This disclosure relates generally to detectors for particular chemicals or contaminants.

<CIT> describes a multimode gas sensor platform comprising an array of electrode pairs oriented on a substrate and a plurality of detection zones, wherein at least a portion of individual electrode pairs are separately addressable.

<CIT> describes a device including a light source for providing light, a sensing element and a detector wherein the sensing element includes a nanofiber, which includes at least one oxygen sensitive compound.

<CIT> describes nucleic acid-based optical sensors, sensor arrays, sensing systems and sensing methods for intelligent sensing and detection of unknown materials by way of real-time feedback and control of sampling conditions.

The claimed invention is defined by the independent claim. Additional embodiments are defined by the dependent claims.

In some circumstances, it may be advantageous to detect specific chemicals or contaminants in the environment, and in particular, airborne contaminants. Airborne contaminants may include toxic industrial chemicals (TICs), chemical warfare agents (CWAs), and non-traditional agents (NTAs). These contaminants can attack skin, blood, the respiratory system, and nervous system, leading to illness, incapacitation, and, with a sufficiently high dose, death. Explosive vapors represent another threat. For example, air enriched with fuel at an appropriate ratio can be ignited by firing a weapon. Confined space threats may include oxygen levels, carbon monoxide, hydrogen sulfide, and the like. Low levels of oxygen can cause asphyxiation while high levels can cause hyperoxia that causes disorientation, seizures, and nervous system damage. In some embodiments, the presence of these conditions may result in proximate danger to exposed personnel, and may indicate an imminent or ongoing threat. In some circumstances, the presence of certain chemicals may indicate a leak or a failure in storage or processing of the chemical. A handheld or wearable chemical detector may be used to detect a specific chemical or chemicals in the environment of the detector and may be configured to transmit or display information about the presence of the specific chemical or chemicals. This may provide those exposed to the chemicals an opportunity to take appropriate steps to minimize risks by carrying out measures to protect themselves, such as donning personal protective equipment (PPE).

Referring to <FIG>, a tactical chemical detector, shown generally at <NUM>, comprises a sensing assembly <NUM> comprising a light array <NUM>; a sensor optic <NUM>; and a sensor array <NUM>. Tactical chemical detector <NUM> may further comprise a power source <NUM> configured to selectively provide power to various components of tactical chemical detector <NUM>, including light array <NUM> and sensor array <NUM>. Sensing assembly <NUM> is disposed within a housing <NUM>. Power source <NUM> is also disposed within housing <NUM> of tactical chemical detector <NUM>.

Sensing assembly <NUM> is configured to identify particular chemicals or contaminants. The chemicals or contaminants may be airborne chemicals or contaminants. In some embodiments, when a particular chemical or contaminant has been identified by sensing assembly <NUM>, tactical chemical detector <NUM> may be configured to generate an alert in response to the presence of the chemical or contaminant. Tactical chemical detector <NUM> may further be configured to display or transmit an indication of the alert.

In some embodiments, sensor array <NUM> may comprise a substrate <NUM>, and substrate <NUM> of sensor array <NUM> may comprise a printed circuit board <NUM>. Printed circuit board <NUM> may further comprise a control circuit <NUM>. Control circuit <NUM> may be in communication with sensing assembly <NUM> and with sensors <NUM>. Control circuit <NUM> may be configured to receive inputs from sensors and to determine whether particular chemicals or contaminants have been identified.

In some embodiments, sensor array may be configured to be removeable and replaceable by a user.

Housing <NUM> has a first side <NUM> and a second side <NUM>. In some embodiments, housing may further comprise a ring <NUM>, such as an elastomeric ring, extending between and connecting together first side <NUM> and second side <NUM> of housing <NUM>. First side <NUM> of housing <NUM> may define a first opening <NUM>, and second side <NUM> of housing <NUM> may define a second opening <NUM>. Second opening <NUM> may comprise a vent <NUM>. Vent <NUM> may be configured to allow air to be released from interior of housing <NUM> of tactical chemical detector <NUM>.

In some embodiments, tactical chemical detector <NUM> may further comprise a pump <NUM>. Pump <NUM> may be disposed in proximity to and in communication with second opening <NUM> of housing <NUM>. As shown in <FIG>, pump <NUM> may be configured to pull air in to tactical chemical detector <NUM> through first opening <NUM> in housing <NUM> and to cause air to pass through sensing assembly <NUM> and to exit from housing <NUM> through second opening <NUM> of housing <NUM>. A rear baffle <NUM> may be configured to partially enclose pump <NUM>, thereby directing air through second opening <NUM> rather than allowing air to escape and remain within housing <NUM> of tactical chemical detector <NUM>. Pump <NUM> may comprise a blower.

Sensing assembly <NUM> is configured to sense particular chemicals or contaminants. Sensor array <NUM> may comprise a plurality of sensors <NUM> arranged on a substrate <NUM>, as shown in <FIG>. Sensors <NUM> comprise organic conductive or semi conductive nanofiber chemical sensors. The nanofibers used in sensors <NUM> are synthesized with specific functional groups that can interact with airborne chemicals, materials, vapors, and particles. The nanofibers may be deposited on an interdigitated electrode to form an electrode-nanofiber array (hereinafter referred to as a "sensor"). Interaction of the nanofibers with certain airborne materials may change the electrical characteristics of sensor <NUM>. An increase or decrease in a particular electrical characteristic, including measured current or effective resistance, of sensor <NUM> may occur as a result of these airborne material interactions.

Nanofiber sensors <NUM> may have excellent sensitivity and selectivity, and may be suitable for miniaturized, low-power devices. Nanofiber sensors <NUM> may have a small area. For example, in some embodiments, each sensor may be <NUM> x <NUM>. This may allow for a high density of sensors <NUM> in a small instrument. Nanofibers tend to be selective to a class of compounds (e.g., amines). Sensing assembly <NUM> may be configured to identify specific chemicals based on the aggregate response of the sensor array <NUM>. Detectable chemicals may each produce a unique response signature that can be matched to known and/or predetermined response signatures in a library of response signatures.

Nanofiber sensors <NUM> are based on organic nanofibers. The nanofibers may be self-assembled from building block molecules functionalized to interact specifically with certain chemicals or classes of chemicals. Once assembled, the nanofibers may be deposited onto an electrode pair to create chemiresistive sensors (i.e., sensors that signal detection of a chemical by changing electrical resistance). The change in resistance is due to a change in charge carrier density caused by electron transfer with the chemical. The interaction is non-covalent and reversible.

Organic conductive or semiconductive nanofibers with different functional groups may have a different response to the same airborne material. By using one or more different sensors <NUM> in an array of such sensors, a response signature can be established for a particular airborne material. Sensors <NUM> can be configured to detect a variety of airborne chemicals, including toxins, combustion by-products, and explosives. Non-limiting examples of suitable nanofibers can be formed by self-assembly of building block compounds such as carbazole-cornered, arylene-ethynylene tetracyclic macromolecules, indolocarbazole derivatives thereof, substituted perylene tetracarboxylic diimide molecule, substituted a <NUM>,<NUM>,<NUM>,<NUM>-tetracarboxyl perylene molecule, and mixtures thereof.

To activate sensor materials, sensors <NUM> are exposed to light. Sensor optic <NUM> is configured to generally direct light toward sensors <NUM> in a sufficient magnitude to activate corresponding nanofiber materials. Light may comprise light in the visible spectrum. Light array <NUM> is configured to provide light to each of the plurality of sensors <NUM>. Light array <NUM> comprises a plurality of light sources <NUM> disposed on a substrate <NUM>. Substrate <NUM> may comprise a printed circuit board <NUM>. In some embodiments, light sources <NUM> may be light emitting diodes. Light sources <NUM> may be configured to provide light of at least about <NUM> lux.

In some embodiments, light array <NUM> may be generally annular in shape. Light array <NUM> may define an opening <NUM> through the center of light array <NUM>. Light sources <NUM> may be distributed around opening <NUM>. In some embodiments, first and second openings <NUM>, <NUM> may be generally circular and opening <NUM> of light array <NUM> may be coaxially aligned with both first opening <NUM> in first side <NUM> of housing <NUM> and second opening <NUM> in second side <NUM> of housing <NUM>.

Sensor optic <NUM> may be generally annular, and may define a generally circular opening in the center <NUM> of sensor optic <NUM>. Generally circular opening <NUM> of sensor optic <NUM> may be configured to be coaxially aligned with at least one of opening <NUM> in light array <NUM>, first opening <NUM> in first side <NUM> of housing <NUM> and second opening <NUM> in second side <NUM> of housing <NUM>.

Sensor optic <NUM> is configured to collimate light and to direct it to the plurality of sensors <NUM>. Sensor optic <NUM> has a collector side <NUM> and an emitter side <NUM>. Sensor optic <NUM> comprises a plurality of optic elements <NUM> extending through sensor optic <NUM> from collector side <NUM> to emitter side <NUM>. Each optic element <NUM> is in optical communication with one of the plurality of light sources <NUM>. Each optic element <NUM> is configured to collect the light from light sources <NUM> of light array <NUM> on collector side <NUM> of sensor array and to emit the light from optic element <NUM> at emitter side <NUM> of sensor optic <NUM>. In some embodiments, optic elements <NUM> may be disposed around a circumference of generally circular opening <NUM> of sensor optic <NUM>.

In some embodiments, tactical chemical detector may further comprise an array of nanofiber-based sensors combined with at least one additional sensor for ethylene oxide, carbon monoxide, oxygen, and lower explosive limit of explosive vapors (not shown). Nanofiber sensors <NUM> may not be able to accurately detect ethylene oxide, carbon monoxide, oxygen, and lower explosive limit. A processor (not shown) may be disposed on a printed circuit board (PCB) <NUM> configured to operate the at least one additional sensor. in some embodiments, the processor may be configured to operate the at least one additional sensor and sensors <NUM>. the processor may also be configured to operate any alerts and algorithms associated with determining the identity of chemicals present.

A lip <NUM> may extend around an outer perimeter of sensor optic <NUM>, as shown in <FIG>. Lip may be configured to allow sensor optic <NUM> to accept light array <NUM>, thereby securing light array <NUM> in a position relative to sensor optic <NUM>. Each light source <NUM> from light array <NUM> is associated with an optic element <NUM>. Lip <NUM> also may also prevent air flowing through center of light array <NUM> and sensor optic <NUM> from travelling between sensor optic <NUM> and light array <NUM>, instead helping to direct air through sensor optic <NUM> to sensor array <NUM>.

Emitter side <NUM> of sensor optic <NUM> may comprise at least one mixing baffle <NUM> as shown in <FIG>. The at least one mixing baffle <NUM> may be configured to divert air travelling through center of sensor optic <NUM>, and to distribute the air to travel across the plurality of sensors <NUM>. A wall <NUM> may extend from a perimeter of emitter side <NUM> of sensor optic <NUM> and generally orthogonal to emitter side <NUM>, thereby enabling sensor optic <NUM> to surround the plurality of sensors <NUM> on sensor array substrate <NUM>.

In some embodiments, sensor optic <NUM> may comprise of an optics-grade plastic such as an optics-grade polycarbonate or an optics-grade acrylic. The plurality of optic elements <NUM> may be integrally formed within sensor optic <NUM>.

Sensor array <NUM> may comprise a plurality of sensors <NUM> disposed on substrate <NUM>. Each sensor <NUM> is associated with one of the plurality of optic elements <NUM>, and is in optical communication with at least one light source <NUM>. The plurality of sensors <NUM> may be disposed in an arrangement on substrate <NUM> such as, for example, in a circular arrangement. A plurality of vent openings <NUM> may be disposed around an outer perimeter of the sensor arrangement. In some embodiments, there may be one vent opening <NUM> associated with each sensor <NUM>. In some embodiments, at least a portion of a vent opening <NUM> may be disposed between each sensor <NUM> and wall <NUM> of sensor optic <NUM>. Wall <NUM> may direct air flowing between sensor optic <NUM> and sensor array <NUM> to exit through the plurality of vent openings <NUM>.

In some embodiments, an air-permeable hydrophobic material <NUM> may be disposed within housing <NUM> and may be configured to cover first opening <NUM> in housing <NUM>. Hydrophobic material <NUM> may be configured to reduce or prevent moisture from entering housing <NUM>. A filter <NUM> may be disposed within housing in proximity to first opening <NUM> such that hydrophobic material may be disposed between filter <NUM> and first opening <NUM> of housing <NUM>. Filter <NUM> may be configured to cover first opening <NUM> of housing <NUM>, thereby filtering fluids entering housing <NUM> through first opening <NUM>. Openings in filter <NUM> may be sized to allow air to pass through into tactical chemical detector <NUM> but to prevent particles that might foul sensors <NUM> from passing through.

As shown in <FIG>, when pump <NUM> is operating, air may enter tactical chemical detector <NUM> through first opening <NUM> in first side <NUM> of housing <NUM>, flowing first through hydrophobic material <NUM>, then through filter <NUM>. Air may then flow through opening <NUM> in center of light array <NUM> and through opening <NUM> in center of sensor optic <NUM>. Upon reaching substrate <NUM> of sensor array <NUM>, air may change directions, flowing radially outward between sensor optic <NUM> and sensor array <NUM> past the plurality of sensors <NUM> and toward an outer perimeter of sensor arrangement. The at least one mixing baffle <NUM> may help to direct air toward each of the plurality of sensors <NUM>. Air may travel across sensors <NUM> to vent openings <NUM> disposed in substrate <NUM> of sensor array <NUM> along the outer perimeter of sensor arrangement. After passing through substrate <NUM>, air may be confined by rear baffle <NUM>, then drawn by pump <NUM> through vent <NUM> in second opening <NUM> of housing <NUM> to exit tactical chemical detector <NUM>.

In some embodiments, tactical chemical detector <NUM> may be configured to produce a haptic alert upon the detection of a particular chemical or chemicals. For example, in some embodiments, tactical chemical detector <NUM> may further comprise a haptic motor <NUM>. Haptic motor <NUM> may be in communication with control circuit <NUM> and, therefore, in communication with sensing assembly <NUM>. Upon a determination by control circuit <NUM> that a particular chemical has been detected, control circuit <NUM> may send inputs to cause haptic motor <NUM> to activate. The determination that a particular chemical has been detected may be based on changes in the electrical characteristics of sensor <NUM>. Upon activation, haptic motor may begin vibrating and may cause tactical chemical detector <NUM> to vibrate.

In some embodiments, tactical chemical detector <NUM> may be configured to produce an audible alert upon the detection of a particular chemical or chemicals. For example, in some embodiments, tactical chemical detector <NUM> may further comprise a piezoelectric element <NUM>. Piezoelectric element <NUM> may be in communication with control circuit <NUM> and, therefore, in communication with sensing assembly <NUM>. Upon a determination by control circuit <NUM> that a particular chemical has been detected, control circuit <NUM> may send inputs to cause the activation of piezoelectric element <NUM>. The activation of piezoelectric element <NUM> may cause tactical chemical detector <NUM> to produce an audible alert.

In some embodiments, tactical chemical detector <NUM> may be configured to produce a visual alert upon the detection of a particular chemical or chemicals. For example, tactical chemical detector <NUM> may further comprise at least one light source <NUM> and an associated printed circuit board (PCB) <NUM> configured to provide a visual alert. The at least one light source <NUM> and associated PCB <NUM> may be in communication control circuit <NUM> and, therefore, in communication with sensing assembly <NUM>. Housing <NUM> may comprise at least one light alert opening <NUM>. A transparent or translucent protective shroud may cover light alert opening <NUM>. Each light source <NUM> may be disposed within housing <NUM> and positioned so that, when light source <NUM> has been activated, light may shine through light alert opening <NUM>. A light guide <NUM> may be configured to direct light from light source <NUM> to light alert opening <NUM>. Each of the at least one light sources <NUM> and associated PCBs <NUM> may be in communication with control circuit <NUM>. Upon a determination by control circuit <NUM> that a particular chemical has been detected, control circuit <NUM> may send inputs to the at least one light source <NUM> and associated PCBs <NUM> that may cause the activation of the at least one light sources <NUM>, thereby producing a visual alert. PCB may also be configured to identify detected chemicals and cause the generation of an alert to notify the user of the presence of a potential threat.

In some embodiments, tactical chemical detector <NUM> may further comprise a display panel (not shown). Display panel may be in communication with control circuit <NUM> and, therefore, in communication with sensing assembly <NUM>. Display panel may be configured to display a visual alert upon the detection of a particular chemical.

In some embodiments, alert may remain active until it has been acknowledged. At least one acknowledgement button <NUM> may be disposed on housing <NUM>. Activating acknowledgement button <NUM> may activate an activation switch <NUM> within housing <NUM> that may terminate alert.

In some embodiments, tactical chemical detector <NUM> may comprise two acknowledgement buttons <NUM>. For example, a first acknowledgement button <NUM> may be disposed on a first side <NUM> of ring <NUM> or on a first portion <NUM> of housing. A second acknowledgement button <NUM> may be disposed on a second side <NUM> of ring <NUM> or on a second portion <NUM> of housing <NUM>. Either of the two acknowledgement buttons <NUM> may be used to turn off or deactivate alert. Having acknowledgement buttons <NUM> disposed in two different locations of housing may facilitate acknowledging alerts for both right- and left-handed people since either acknowledgement button <NUM> may be activated with either hand of a user.

In some embodiments, tactical chemical detector <NUM> may be configured to produce at least two types of alerts. For example, tactical chemical detector <NUM> may be configured to produce both an audible and a visual alert. In some embodiments, tactical chemical detector <NUM> may comprise haptic motor <NUM>, piezoelectric element <NUM>, and an alert light source <NUM> and associated PCB <NUM>, and may be configured to produce a haptic alert, an audible alert, and a visual alert. In some embodiments, the alerts may be produced sequentially. For example, if an alert has not been acknowledged within a predetermined amount of time, a second alert may be activated. If the second alert is not acknowledged within a predetermined amount a third alert may be activated. For example, when a particular chemical has been detected, tactical chemical detector <NUM> may produce a haptic alert. If the haptic alert is not acknowledged within a first predetermined amount of time, tactical chemical detector <NUM> may then produce an audible alert. If the audible alert is not acknowledged within a second predetermined amount of time, tactical chemical detector <NUM> may produce a visual alert. In some embodiments, if the alert is still not acknowledged, alerts may be combined or may alternate. For example, tactical chemical detector <NUM> may alternate a haptic alert with an audible alert, or may combine a haptic alert with an audible alert.

If an alert has sounded and not yet been acknowledged, and tactical chemical detector <NUM> detects a second chemical, in some embodiments, tactical chemical detector <NUM> may begin a second alert. For example, if tactical chemical detector <NUM> has detected a first particular chemical and produced a haptic alert and progressed to an audible alert, and then a second particular chemical is detected, tactical chemical detector <NUM> may revert to the haptic alert and begin the alert sequence all over.

In some embodiments, tactical chemical detector <NUM> may comprise a clip <NUM>. Clip <NUM> may be fastened to or be an integral part of housing <NUM>. Clip <NUM> may be configured to be able to be securely fastened to a strap, a belt, a pocket or other article of clothing, or other suitable location. Clip <NUM> may be configured to lock in place, thereby preventing tactical chemical detector <NUM> from falling off. Clip <NUM> may be secured to second side of housing <NUM>.

In some embodiments, tactical chemical detector <NUM> may be configured to self-test. Self-testing may be conducted either based on an input received through a user interface or at a predetermined time interval or at the occurrence of a predetermined event such as tactical chemical detector <NUM> being turned on. In some embodiments, as part of the self-test function, tactical chemical detector <NUM> may be configured to indicate whether filter <NUM>, sensor <NUM>, or a battery (not shown) needs to be replaced, and whether the system is operating normally.

Referring to <FIG>, in some embodiments, a method <NUM> for detecting chemicals or contaminants comprises providing a tactical chemical detector <NUM> having a light source <NUM> configured to provide light to a plurality of sensors <NUM> as shown in step <NUM>. Light source <NUM> is collimated in step <NUM>. In step <NUM>, the collimated light is directed to the plurality of sensors <NUM>. In step <NUM>, a fluid is pumped through the tactical chemical detector. Tactical chemical detector <NUM> is configured to cause the fluid to pass over the plurality of sensors <NUM> disposed within tactical chemical detector <NUM>. The fluid may be air. Sensors <NUM> comprise nanofiber chemical sensors. A sensing assembly of tactical chemical detector <NUM> may comprise a plurality of mixing baffles <NUM> configured to direct the fluid toward each of the nanofiber chemical sensors <NUM>. In step <NUM>, the fluid is directed through one of a plurality of vent openings <NUM> after the fluid has passed over the sensors <NUM>. The method may further comprise the step <NUM> of providing at least one of a haptic motor <NUM>, a piezoelectric element <NUM>, and an alert light source <NUM> and associated printed circuit board <NUM>; and causing at least one of the haptic motor <NUM>, the piezoelectric element <NUM>, and the alert light source <NUM> and associated printed circuit board <NUM> to generate an alert upon the detection, by the nanofiber chemical sensors, of a particular chemical.

The above description is considered that of the preferred embodiments only. Modifications of the disclosure will occur to those skilled in the art and to those who make or use the disclosure. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims.

Claim 1:
A sensing assembly comprising:
a light array (<NUM>) comprising a plurality of light sources (<NUM>); and
a sensor array (<NUM>) comprising a plurality of sensors (<NUM>) disposed on a substrate, each sensor (<NUM>) in optical communication with one of the plurality of light sources (<NUM>);
wherein at least one vent opening (<NUM>) extends through the substrate of the sensor array (<NUM>);
wherein the sensors are nanofiber-based chemical sensors; characterised by a sensor optic (<NUM>) comprising a plurality of optic elements, each optic element (<NUM>) in optical communication with one of the plurality of light sources (<NUM>), wherein the optic elements (<NUM>) are configured to collimate light from the light sources (<NUM>); and
wherein each of the plurality of sensors (<NUM>) is in optical communication with one of the plurality of light sources (<NUM>) via at least one of the plurality of optic elements (<NUM>).