Integrated ion sensing device and method

Abstract

The present disclosure relates to integrated ion sensing devices and methods. An integrated ion-sensitive probe is provided. In examples, the ion-sensitive probe can include a semiconductor substrate and a first passive electrode attached to the semiconductor substrate. The first passive electrode can be configured to contact a solution and provide a first voltage that is a function of an ion concentration in the solution. In certain examples, a passive reference electrode can be collocated on the semiconductor substrate. In some examples, processing electronics can be integrated on the semiconductor substrate.

Description

[0001] This application is a continuation-in-part of International Patent Application No. PCT / EP2018 / 062505, filed May 15, 2018, which entered the National Stage in China on November 15, 2019, and has a national application number of 201880032150.7, entitled “Integrated Ion Sensing Device and Method.”

[0002] Priority

[0003] This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 506,318, entitled “Integrated Ion Sensing Device and Method,” filed May 15, 2017, by O’Donnell. TECHNICAL FIELD

[0004] The present disclosure relates to integrated ion sensing devices and methods. BACKGROUND

[0005] The “gold standard” for measuring ion concentrations in aqueous solutions involves a glass electrode. A glass electrode system is a measurement device that has an ion-selective or ion-sensitive electrode made of a doped glass ion that is sensitive to a particular ion. A glass electrode system can include two electrodes, one for sensing a target ion, such as a hydrogen ion (H + ), and another for providing a reference. Both electrodes provide a voltage at the interface of the liquid being measured. The reference electrode provides a nearly constant voltage that can be independent of the target ion concentration, and the voltage provided by the sensing or indicating electrode varies with the target ion concentration. The voltage is transmitted through a wire medium to an amplifier system, which is then processed for display or data collection. In some cases, the voltage can be converted to a digital value, for example, by digitizing with an analog-to-digital converter (ADC). Characteristics of glass electrode systems that can interfere with measurements include an output impedance that is typically on the order of 40 megaohms (MΩ) to 800 MΩ, noise coupling with the wire medium, and expense of the wire medium and probe. In addition to glass electrodes, there are low-performing disposable solutions, such as litmus paper, which are passive strips that change color depending on the concentration of the target ion. Measurements with litmus paper are not considered to be precise because, for example, using litmus paper involves a subjective color reading, the paper itself can interfere with small samples, and it can be difficult to manufacture paper that covers the entire range of ion concentrations. SUMMARY

[0006] Ion-sensitive field effect transistors (ISFETs) based on the activation of the FET gate can produce an output source-drain current related to a pH index (Non-Nernstian). This approach can be limited in terms of charge trapping, hysteresis, and drift. Additionally, ISFETs only provide an indicating electrode, often requiring an additional external reference electrode.

[0007] This document describes integrated ion-sensitive probes. They can include a semiconductor substrate and an attached first passive electrode. The first passive electrode can be configured to contact a solution and provide a first voltage that is a function of an ion concentration in the solution. A passive reference electrode can be collocated on the semiconductor substrate. Processing electronics can be integrated on the semiconductor substrate.

[0008] This overview is intended to provide a summary of the subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation. The detailed description is included to provide further information about the present patent application. BRIEF DESCRIPTION OF DRAWINGS

[0009] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of example, various embodiments discussed in the present document.

[0010] Figure 1 Examples of passive solid-state ion-sensitive electrodes are generally shown.

[0011] Figure 2 Examples of integrated solid-state ion probes are generally shown.

[0012] Figure 3 A block diagram of an example of an ion probe is generally shown.

[0013] Figure 4 Example circuits for directly providing a signal indicative of H+ ion concentration rather than pH indication are generally shown.

[0014] Figure 5A And Figure 5B Examples of configurations of reference electrodes are generally shown.

[0015] Figure 6A And Figure 6B Examples of probe layouts including reference electrodes and one or more indicating electrodes are generally shown.

[0016] Figure 7 Examples of methods of operating ion-sensitive probes including passive electrodes integrated on semiconductor substrates are generally shown.

[0017] Figure 8A and Figure 8B An example channel 822 is generally shown for regulating fluid flow to an underlying ion sensing system as described above.

[0018] Figures 9A-9D An example channel is generally shown that can allow a target material or target solution to be carried to or through a passive ion sensitive electrode.

[0019] Figure 9E An example substrate including a filter channel is generally shown.

[0020] Figure 9F An exploded view of an example of a stack structure for directing test material to, for example, a passive ion sensitive electrode is generally shown.

[0021] Figures 10A-10E An example channel is generally shown that can include a regulating element adjacent or proximate to the channel.

[0022] Figure 11 An example substrate or packaging material having a lateral microfluidic channel and a heating device is generally shown.

[0023] Figure 12 An example substrate or packaging material having a microfluidic channel and a magnetic device is generally shown.

[0024] Figure 13A and Figure 13B An interface including a substrate and a gel is generally shown.

[0025] Figure 14A and Figure 14B An example electrode structure is generally shown.

[0026] Figure 15 An example electrode structure including multiple electrodes in a common substrate is generally shown.

[0027] Figure 16A An ion sensitive material having a surface topology for increasing surface area is generally shown.

[0028] Figure 16B Alternative shapes of ion sensitive material that can be exposed in an electrode are shown.

[0029] Figure 17A and Figure 17B A sensor according to various embodiments of the present subject matter is generally shown.

[0030] Figures 18A-18DExemplary semiconductor electrode structures are generally shown incorporating conduits for target material to reach or pass one or more electrodes.

[0031] Figure 19A and Figure 19B Exemplary ion sensor assemblies are generally shown including connectors such as conduits and tubes.

[0032] Figure 20 Exemplary ion sensor assemblies are generally shown having multiple sensing electrodes or elements.

[0033] Figure 21 Exemplary electrode structures for ion sensors are generally shown in cross-section.

[0034] Figure 22 Exemplary electrode structures and systems for ion sensors are generally shown in cross-section.

[0035] Figure 23 Exemplary electrode structures and systems for ion sensors are generally shown in cross-section, for example for submersion ion sensors.

[0036] Figure 24 Exemplary sensor structures are generally shown to mitigate premature sensor replacement due to channel fouling.

[0037] Figure 25 Exemplary sensor structures are generally shown including temperature sensors.

[0038] Figures 26A-26C Exemplary ion sensor structures are generally shown including a tunable resistive material in cross-section.

[0039] Figure 27 Exemplary sensors are generally shown including an array of indicator electrodes.

[0040] Figure 28 Exemplary sensor structures are generally shown having conductivity sensors.

[0041] Figure 29A and Figure 29B Exemplary electrode structures of embodiments are generally shown including a shroud to protect electrodes.

[0042] Figure 30 Sensor structures are generally shown that can allow for extended operation using addressable or sequentially activated electrodes.

[0043] Figure 31 Exemplary electrode structures of sensors that can be used as part of systems are generally shown. Figure 30

[0044] ​Figure 32 A flowchart of an exemplary method for operating a device including a passive ion-sensitive electrode is generally shown.

[0045] Figure 33 Another example of an array sensor is generally shown. DETAILED DESCRIPTION

[0046] The present inventors have recognized that ion sensing systems including passive, solid-state, ion-sensitive electrodes can be greatly reduced in size and cost. The subject matter of the present invention can also help provide reduced drift as compared to other solid-state ion sensing solutions. Temperature sensing can be co-located with ion sensing electrodes, for example providing auxiliary testing to help accurately report pH. Co-located electrodes and temperature sensors can have very low thermal mass, which can help provide faster temperature equilibration response, which in turn can help reduce temperature damage to small samples. Amplifier systems and memory can be co-located with electrodes. This can allow for factory or field calibration of individual electrodes or sensors, which can be more difficult with glass electrodes because the amplifier and sensor are not uniquely coupled. Finally, the much smaller size and cost of the present approach can open up new uses and markets for glass electrodes that are currently not possible, for example the prospect of high performance disposable ion sensing probes.

[0047] Figure 1 An example of a passive solid-state ion-sensitive electrode 101 is generally shown. The electrode 101 can include a portion of a substrate 106, for example a semiconductor fabrication process can be used to integrally form an ion-sensitive material 107, electrical interconnect traces 108, and insulators 109 thereon. For example, the substrate can include a semiconductor substrate such as a silicon-based substrate 106, a glass substrate, or a polymer substrate. The "passive" electrode 101 refers to the fact that although the electrode 101 is integrated with the semiconductor substrate, it is not integrated as part of a field effect transistor (FET) or other transistor structure. Thus, the passive electrode 101 is not part of a transistor gate region, a transistor drain region, or a transistor source region of a FET (although the electrode 101 can be fabricated on a region of the substrate 106 that can serve as a region of a body terminal or transistor). Thus, because the electrode 101 is not part of a gate, source, or drain terminal or equivalent terminal of a transistor, it can be considered a "passive" electrode even though it can be interconnected (for example, through integrated semiconductor wiring traces) to an active transistor device, for example a FET input device of an operational amplifier, a gate of a FET, etc.

[0048] As part of a method of detecting ion concentration in a solution, the ion-sensitive material 107 can be exposed to and in contact with a target material or solution sample 110. In one example, the ion-sensitive material 107 can attract or repel ions such that an electrical potential develops across the interface 107 between the sample 110 and the ion-sensitive material. The trace 108 can provide a low impedance conductor to provide or transfer a voltage to a processing or sensing electronics or circuitry. The insulator 109 can provide a structure that allows the ion-sensitive material 107 to contact the trace 108 and isolate the trace 108 from the sample solution 110. For example, the ion-sensitive material 107 can include, but is not limited to, iridium oxide, silicon nitride, tantalum pentoxide, or one or more other materials that are reactive to a target ion. For example, the trace 108 can include, but is not limited to, gold, silver, platinum, or other conductive materials. In certain examples, the insulator 109 can include, but is not limited to, silicon oxide, silicon nitride, a polymer, or other insulating material that is substantially liquid impermeable.

[0049] Figure 2 An example of an integrated solid state ion probe 203 is generally shown. For example, the integrated solid state ion probe 203 can include an indicating electrode 201, a reference electrode 202, integrated electronics 211, and a substrate 206 on which each of the electrodes 201, 202 and electronics 211 can be formed. In certain examples, the integrated solid state ion probe 203 can have a width and length of 2 mm or less. In certain examples, the electronics 211 can include one or more amplifiers for receiving signals provided by the electrodes 201, 202 and providing amplified signals to electronics coupled to a connector 212 of the probe. For example, the connector 212 can include a wire, a cable, a printed circuit board, or other structure for coupling the probe to a device for receiving signals from the probe. Figure 2 An advantage of the illustrated integrated solid state ion probe 203 is that low power or low voltage signals provided by the electrodes 201, 202 can be processed or pre-processed with amplifiers co-located with the electrodes 201, 202. This can provide a significant advantage over certain electronic probes because the lead length of conductors to the amplifiers is orders of magnitude shorter in length. The smaller lead length reduces the likelihood that the electrical conductivity of the signals from the electrodes 201, 202 is disrupted by electrical interference and also reduces the magnetic permeability to stray leakage currents. The electronics 211 can include amplifiers. In some examples, the electronics 211 can include an analog-to-digital converter. In some examples, the electronics 211 can include a wireless transmitter, a wireless receiver, or a combination thereof, such as including a transceiver. In certain examples, the electronics 211 or the connector 212 or both of the integrated solid state ion probe 203 can be sealed from contact with a solution sample being measured.

[0050] Figure 3A block diagram of an example of an integrated solid state ion probe 303 is shown generally. The integrated solid state ion probe 303 can include a substrate 306 and / or a circuit board 316, or include a tape made of or from a polymer or other material including traces 308 and terminals 312 of a meter. The substrate 306 can include a reference electrode 302, an indicating electrode 301, and an amplifier 313. For example, the indicating electrode 301 and the reference electrode 302 can be coupled in series between a reference voltage terminal and an input to the amplifier 313. The electrical connection or interface between the indicating electrode and the reference electrode can be formed by an ion exchange interface between a target solution and a reference solution during ion concentration measurement of the target solution. In Figure 3 The amplifier 313 can be in a voltage follower configuration, among others. Such a configuration can provide a high impedance amplifier input at which to sense the voltage of the electrodes 301, 302, and a low impedance output, for example, to efficiently pass the detected voltage representation to a meter device without risk of noise damage as great as with a glass probe. Other amplifier configurations can be used that are integrated with the substrate 306. Collocating an amplifier or amplifier system with one or more electrodes 301, 302 of the integrated solid state ion probe 303 can significantly reduce the output impedance of the integrated solid state ion probe 303 as compared to a glass electrode.

[0051] Additionally, the integration of the electrodes 301, 302 with the substrate 306, alone or with or without the integration of one or more electrodes 301, 302 with an amplifier 313 or amplifier system on the substrate system, can open new uses for such ion sensitive probes. For example, the electrodes 301, 302 can be made relatively small, and very small solution sample sizes can be used to provide accurate ion measurements. The indicating electrode 301 can be formed on the bottom of a small volume container that can also be integrated on a silicon substrate, so that a drop of solution can be contained, for example, can completely cover the indicating electrode 301, and a bridge to the reference electrode 302 can be formed for measurement purposes. The small size format also allows for use of the integrated solid state ion probe 303 in small areas. Such an integrated solid state ion probe 303 can also provide accurate ion measurements when immersed in a large volume of solution. Other applications that can be implemented with the integrated solid state ion probe 303 are disposable or semi-disposable probes. The passive electrode structure discussed above, and further integration of the reference electrode discussed below, can be manufactured using technology for manufacturing integrated electronic devices that can allow for mass consistent manufacturing of probes at a fraction of the cost of other technologies. Such probes can be considered disposable probes or single use probes.

[0052] In contrast to, for example, pH indication, Figure 4A circuit 480 is generally shown which can directly provide a signal indicative of ion concentration. The circuit can include, for example, an exponential or antilog circuit coupled to an output 481. The antilog circuit can include an amplifier having a non-inverting input coupled to a reference voltage (e.g., ground), a diode coupled between the output of the pH circuit and the inverting input of the amplifier, and a resistive feedback coupled between the output and inverting input of the amplifier.

[0053] Figure 5A and 5B An example of a configuration of a reference electrode 502 is generally shown. Figure 5AA cross-section of an example of an integrated solid state ion probe 503 that can include an indicating electrode 501 and a reference electrode 502 is generally shown. The indicating electrode 501 can include a first ion-sensitive material 507 having an outer surface that can be in contact with a target solution. In certain examples, the reference electrode 502 can include a second ion-sensitive material 517 that can be in contact with a reference material 518 having a known or specified ion concentration, such that the reference electrode 502 can provide a reference or base voltage. The indicating electrode 501 can be exposed to a material or solution in need of ion measurement. The reference electrode 502 can be simultaneously exposed to the material or solution to form an electrical connection between the indicating electrode 507 and the reference electrode 502. The reference electrode 502 can provide a reference or base voltage, for example, by having the second ion-sensitive material 517 in contact with a reference solution having a controlled ion concentration. In certain examples, the reference electrode 502 can include a container that includes a containment barrier 519 surrounding an exposed surface of the second ion-sensitive material 517. The containment barrier 519 can provide a container for the reference solution 518. In some examples, a top porous membrane 520 can be coupled to the top of the containment barrier 519, for example, can provide a top liquid barrier, such that the reference solution 518 can be substantially sealed in a container that includes the second ion-sensitive material 517 of the reference electrode, the substrate 506 supporting the electrode, the containment barrier 519, and the top membrane 520. In some examples, the reference solution 518 can include a liquid. In some examples, the reference solution 518 can include a gel, which can more easily contain an extended period of time. In certain examples, the reference electrode 502 can include the same ion-sensitive material as used in the indicating electrode 501. In some examples, the second ion-sensitive material 517 of the reference electrode 502 can be different than the first ion-sensitive material 507 of the indicating electrode 501. The sensor employs a liquid junction, allowing an electrical connection to be formed between the indicating electrode 501 and the reference electrode 502. The liquid junction is the interface between the target solution and the reference solution 518 of the reference electrode 502. A channel or mechanism that allows contact between the reference solution 518 and the target solution can allow electrical conductivity between the second ion-sensitive material 517 of the reference electrode 502 and the target solution. The channel or mechanism can include, but is not limited to, for example, a porous or semi-permeable membrane 520 or a microporous material. In certain examples, the container formed by the containment barrier 519 and the top membrane 520 can encase the reference solution 518 around the second ion-sensitive material 517 of the reference electrode 502, thereby helping to ensure that the environment around the second ion-sensitive material 517 is controlled and that the reference electrode 502 produces a consistent voltage regardless of the characteristics of the target solution. In certain examples, the container can incorporate some type of porous junction that can allow ions to flow between the target solution and the reference solution 518 and thus allow an electrical connection to the target solution while reducing or minimizing fluid exchange across the target solution.

[0054] In certain examples, the membrane 520 can accommodate needle puncture and can reseal upon withdrawal of the needle. Such a membrane 520 can fill the reference electrode vessel with the reference solution 518 just prior to using the probe 503 to detect the ion concentration of the target solution. A point-of-use, fillable reference electrode structure can allow a probe user to store a supply of probes 503 for a long period of time without risking contamination of the reference solution 518 of each individual probe 503.

[0055] Figure 5B is another configuration of an example reference electrode 502. The reference electrode 502 can include a substrate 506, a first material 508 that is electrically conductive such as gold, an ion-sensitive material 507, a packaging material 509, and a reference material 510. The substrate 506 can include a semiconductor substrate, and the first material 508 provides traces to route electrical signals to different areas of the substrate 506. The packaging material 509 can protect the substrate 506 and the first material 508, and can provide a vessel for containing the reference material 510. In certain examples, the ion-sensitive material 507 of the reference electrode 502 can provide at least a portion of the interior surface of the vessel. In certain examples, the reference material 510 can be in the form of a gel. In some examples, an upper membrane 520 can extend over the vessel and can be coupled to the packaging material 509, thereby sealing the reference material 510 within the vessel formed by the packaging material 509, the ion-sensitive material 507, and the upper membrane 520. In some examples, the substrate 506 can include active electronics 511 so that one or more signals from the reference electrode 502 can be processed as close to the reference electrode 502 as possible. Such an approach limits the length of the conductive medium from the reference electrode 502, and in certain cases, limits the length of the indicator electrode located in the same location that is exposed to potentially interfering signals as compared to a glass electrode. In some examples, the active electronics 511 can reside on the side of the substrate 506 opposite the ion-sensitive material 507, and one or more signals can be routed to the active electronics 511, such as using one or more through-silicon vias (TSVs) 521.

[0056] Figure 6A and 6B An example of a probe layout 603 that can include a reference electrode 602 and one or more indicator electrodes 601 is generally shown. Figure 6AAn example of a probe layout 603 that can include a reference electrode 602 and multiple indicator electrodes, such as three indicator electrodes 601a, 601b, 601c, is generally shown. Each electrode 601x, 602 can be electrically connected to a respective trace 608 of a substrate 606 of the probe layout 603. Each trace 608 routes a voltage or signal of an electrode to a connector 612 or some other terminal of the substrate 606. In some examples, each trace 608 can route a voltage or signal to an active electronic device that can be integrated with the substrate 606. In some examples, each trace 608 can route a voltage or signal to an integrated electronic device or an active electronic device located on an opposite side of the substrate, such as using TSVs. In certain examples, the active electronic device can include an amplifier circuit, for example, that can buffer or convert signals received via the traces 608 and electrodes 601x, 602 into larger anti-noise signals.

[0057] In certain examples, the reference electrode 602 can include a well, for example, to retain a reference material. The probe layout 603 includes a circle 614 that indicates a location of a containment shell, for example, that can form a portion of a vessel. In certain examples, the diameters of the electrodes 601x, 602 can vary, such as depending on one or more of a number of factors, such as can include an intended environment in which the probe will be used. For example, if the probe is to be used to measure very small samples, the electrodes can also be relatively small. In some examples, the diameters of the electrodes of both the reference electrode 602 and the indicator electrodes 601x can range from < 100 micrometers (um) to 1 millimeter (mm) or more. Good results can be obtained using electrode diameters of 500 um and 300 um. In certain examples, the diameters of the containment shell barriers can be between 1 mm and 6 mm, although other diameters are possible.

[0058] Figure 6B An example probe layout 603 is generally shown having a reference electrode 602 and multiple indicator electrodes, such as three indicator electrodes 601a, 601b, 601c, each having an electrode diameter of about 500 um. Each electrode 601x, 602 can be coupled to a conductor or trace 608 of a substrate 606 of the probe layout 603. Further, each trace 608 and each electrode 601x, 602 can be surrounded by a shield trace 615 of the substrate 606. For example, the shield trace 615 can be coupled to a reference potential, such as ground. In some examples, each trace 608 and each electrode 601x, 602 can have a respective shield trace 615 that can be connected to a respective potential or a common potential, such as ground. Each shield trace 615 can be arranged to protect the electrodes 601x, 602 and electrode conductors or traces 608 from stray electrical interference, for example, by routing such interference to ground.

[0059] Figure 7Aspects of a method 700 of operating an ion-sensitive probe, which can include a passive electrode integrated on a semiconductor substrate, are generally shown. At 701, a passive ion-sensitive probe integrated on a substrate can contact a solution. At 703, a first voltage of a first passive electrode can be amplified or buffered so as to provide an indicative voltage indicative of an ion concentration of the solution. In certain examples, an amplifier can be integrated on a silicon-based or other semiconductor-based substrate, such that the output voltage of the amplifier has greater noise immunity than a signal taken directly from the passive electrode. In some examples, a reference electrode can be located in proximity to the passive electrode on the substrate.

[0060] Figure 8A and Figure 8B Examples of channels 822, such as microfluidic channels, such as for regulating fluid flow to one or more underlying layers of an ion-sensing system as described above, are generally shown. In certain examples, the channels 822 can include sloped sidewalls 831. In some examples, the channels 822 can include stepped sidewalls 832. In certain cases, such sidewalls 831, 832 can help regulate and provide optimal fluid flow to the passive electrode. In certain examples, the sloped or stepped sidewalls 831, 832 can form a circular channel to the ion-sensitive material 807 of the passive ion-sensitive electrode.

[0061] As used herein, "microfluidic" describes concepts related to fluid flow through microfluidic channels or microchannels. Such flow can be defined in terms of a Reynolds number (Re),

[0062] Re = LV avg p / μ,

[0063] where L is the most relevant length scale, μ is the viscosity, r is the fluid density, V avg is the average velocity of the flow. For many microchannels, L is equal to 4A / P, where A is the cross-sectional area of the channel and P is the wetted perimeter of the channel. Due to the small size of microchannels, Re is typically less than 100, often less than 1.0.

[0064] Figures 9A-9D Examples of one or more microfluidic channels 922 that can be used in combination are generally shown, which can allow a target material or target solution to be carried to or through a passive ion-sensitive electrode. Different forces can be employed to assist in the movement of the target solution, including but not limited to, a pumping force, a gravitational force, wicking, capillary action, other surface tension effects, or combinations thereof. Figure 9A Examples of lateral microfluidic channels 922 are shown, which can be used to move a target solution through a sensor substrate 906, through a packaging material of an electrode structure, or through a combination of the substrate 906 and the packaging material.Figure 9B An example of a horizontal microfluidic channel 922 is shown that can move a target solution through a sensor substrate 906, through a packaging material of an electrode structure, or through a combination of a substrate and a packaging material. Figure 9C An example of a vertical microfluidic channel 922 is shown that can move a target solution through a sensor substrate 906, through a packaging material of an electrode structure, or through a combination of a substrate and a packaging material. Figure 9D An example of a combination of vertical and horizontal microfluidic channels 922 that can be used to move a target through a sensor substrate 906, through a packaging material of an electrode structure, or through a combination of a substrate 906 and a packaging material is generally shown.

[0065] In certain examples, a substrate incorporating microfluidic channels can have openings into which one or more filters 923 or other configurations can be inserted to perform or enable system functions (e.g., separation, filtration, etc.). For example, to prevent biofouling, a filter can be inserted that captures particles of at least a certain size and prevents them from fouling or impeding the flow of material to a sensing element.

[0066] Microfluidic channels on different substrates can be combined to flow and manipulate fluid in different planes. A system can include one or more or a combination of structures for separation, filtration, thermal treatment, or magnetic flux manipulation of a target material before it is delivered to a sensor element. In some examples, gravity can be used when fluid flows, for example, through one or more through-holes to an underlying lower layer. In such examples, the through-holes or channels between layers can also contain filters (or gels or other materials) to remove contaminants or can manipulate the fluid in a certain desired way before it is provided to a sensor element. In some examples, a combination of different microfluidic channels can present a target fluid or target material to a sensing element at a desired rate to achieve optimal efficiency of the system.

[0067] Figure 9EExamples of substrates including filtered channels are generally illustrated. In certain examples, the substrate 906 can include one or more microfluidic channels 922 extending laterally through the substrate 906. The through hole 921 can extend vertically through the substrate 906 and can intersect the channel 922. In certain examples, the through hole 921 can extend completely through the substrate 906. In certain examples, a filter 923 can be inserted within the through hole 921. The filter 923 can manipulate a material as it passes through the channel 922. In some examples, the filter 923 can remove one or more constituents of the material. In some examples, the removed constituents of the material can exit the filter 923 and pass through the through hole 921 to another location, such as for collection, disposal, recycling, or one or more combinations thereof. In some examples, a cross-flow technique can be employed to remove the material from the filter 923.

[0068] Figure 9F An exploded view of an example of a stack structure for directing test material to, for example, a passive ion-sensitive electrode is generally illustrated. In one example, the structure can include a first substrate 906 and a second substrate 936. The first substrate 906 can include a vertical microchannel 921 and the second substrate 936 can include a corresponding vertical microchannel such that when the first substrate 906 and the second substrate are stacked together, the vertical microchannel 921 of the first substrate 906 is aligned with the corresponding vertical microchannel of the second substrate 936 to form a continuous vertical microchannel through the stacked substrates 906, 936. In certain examples, the substrate 936 can include one or more additional microfluidic channels or microchannels. In certain examples, the additional microchannels can extend in a different direction than the vertical microchannel. In certain examples, the additional microchannels 922 can intersect another microchannel, such as the vertical microchannel shown with respect to the second substrate 936.

[0069] Figure 10A and Figure 10BAn example of a channel 1022 is generally shown, which can include a conditioning element 1024 adjacent or proximate to the channel 1022. The conditioning element 1024 can include, but is not limited to, a thermal element such as for heating or cooling the surrounding environment, a magnetic element, a microelectromechanical system (MEMS) component, a piezoelectric material, or one or more combinations thereof. In certain examples, a thermal element can be used to change the temperature of the material surrounding the channel 1022 and in turn affect one or more flow characteristics of the material within the channel 1022. In certain examples, a MEMS component can induce vibrations in the channel, affecting fluid flow. In some examples, a MEMS component or a piezoelectric material can induce vibrations in the channel to help prevent fouling of the channel, for example, by reducing the opportunity for fouling material to adhere to the walls of the channel. In certain examples, a MEMS component can include an actuator, a moving component, a rotating component, a movable beam, or other component that can agitate fluid within one or more channels when activated. In certain examples, a MEMS component or a piezoelectric material can occupy a substrate layer, and a channel can occupy a substrate layer adjacent to the substrate layer of the MEMS component.

[0070] Figure 10A An example of a vertical channel 1022 is shown with a conditioning element 1024 that can be located near an opening of the channel 1022. Figure 10B A lateral channel 1022 is shown, where a conditioning element 1024 is located near and extends with the channel 1022. The specific shape of the combined structure can depend on the application and flow of the material. For example, Figure 10A A channel 1022 or through hole is shown, through which material can flow vertically, and a circular conditioning element 1024 can partially or completely surround the through hole, such that fluid will flow within its boundaries. Other applications can include different arrangements (e.g., as Figure 10B As shown, a heating element is adjacent to a channel). Different embodiments can combine different shapes, geometries, and sizes in order to deliver the optimal flow rate or condition of the material to the sensing element for the system to function effectively.

[0071] Figure 10C And 10D Examples of channels 1022 that can be formed using, for example, an etched substrate 1006 and a cover 1025 are generally shown. In certain examples, the structure can include a substrate 1006 having one or more grooves and a cover 1025 that can be configured to cover the grooves to form the channels 1022. In certain examples, the cover 1025 or the substrate 1006 can include a conditioning element 1024.

[0072] Figure 10EAn example portion of a device is generally illustrated that includes an open channel 1022 integrated within a substrate 1006, a cap 1025, and a conditioning element 1024 disposed on top of the cap 1025. In certain examples, the conditioning element 1024 can be electroplated onto the cap 1025, printed onto the cap 1025, sputtered onto the cap 1025, or deposited on the cap 1025 by another suitable method.

[0073] In some examples, piezoelectric material can be combined with microfluidic channels such that application of a voltage exerts a physical vibration / stress on the channel. This vibration or oscillatory stress can act as a micro-pump to move fluid from one region (within the system) to another at a desired rate. In another example, piezoelectric material can be combined with channels / vias of a particular aperture and length to cause the flow rate of fluid to exert a stress or vibration that causes an identifiable / measurable electrical response (from the piezoelectric material). The electrical response can be analogous to the flow rate or pressure of the fluid (through the channel).

[0074] Figure 11 An example of a substrate 1106 or packaging material having one or more lateral microfluidic channels 1122 is generally illustrated that can extend through the substrate 1106 and have a relatively uniform cross-sectional area. In addition to the microfluidic channels, the substrate 1106 can include a thermal device 1124. In certain examples, the thermal device 1124 can be used to change the temperature of the material near or around the channel, which in turn affects the temperature or one or more flow characteristics of the material within the channel 1122. In certain examples, the thermal device 1124 can include a heater, such as an electrical resistance heater. In certain examples, the thermal device 1124 can include a heating element, a piezoelectric element, a magnetic element, or a combination thereof.

[0075] Figure 12 An example of a substrate 1206 or packaging material having one or more microfluidic channels 1222 is generally illustrated that extend through the substrate and have a relatively uniform cross-sectional area. In addition to the microfluidic channels 1222, the substrate 1206 can include a magnetic material 1224 or a magnetic device. In certain examples, the magnetic material 1224 or magnetic device can be used to change the characteristics of the channel 1222 or one or more flow characteristics of the material within the channel 1222. In certain examples, the magnetic material 1224 can be deposited on a layer of the substrate 1206 proximate to the one or more channels 1222. In some examples, Figure 11 a thermal device or Figure 12 the magnetic material 1224 or magnetic device can be formed in a separate substrate that is stacked with the substrate containing the microfluidic channels 1222.

[0076] Figure 13A and 13BAn example of an interface including a substrate 1306 and a gel 1326 is generally shown. As described above, this interface can be a feature of a substrate / gel interface for an ion-sensing electrode. In certain examples, the substrate 1306 can include grooves that can provide more adhesion or contact area for the gel 1326 compared to a substantially flat substrate surface. In certain examples, one or more grooves can have a "u" shaped cross-section 1327. In some examples, a groove can have an "o" shaped cross-section 1328, but still be open to accommodate a gel.

[0077] Figure 14A And 14B An example of an electrode structure 1400 is generally shown. The electrode structure 1400 can include an ion-sensitive material 1407, a channel material 1409 having an opening, a via, or a channel, and a gel material 1426, for example, that can be located within the opening of the channel material 1409. In certain examples, the walls of the opening can be sloped toward one another as the opening progresses toward the ion-sensitive material 1407. In some examples, the walls of the opening can be sloped in a step-wise manner. In some examples, the walls of the opening can be sloped in a continuous, smooth manner.

[0078] Figure 15 An example of an electrode structure 1500 is generally shown that includes multiple electrodes 1501 in or integrated on a common substrate 1506. Each electrode 1501 can include an ion-sensitive material 1507 located at the bottom of an opening 1522, a via, or a channel formed within a channel material 1509. In certain examples, the ion-sensitive material 1507 of one electrode can be located at a different depth within the common substrate 1506 than the ion-sensitive material of a second electrode. In some examples, the ion-sensitive material of a third electrode can be located at a different height within the substrate than one or the second electrode. In certain examples, one or more openings of each electrode can be filled with a gel 1526. In certain examples, an electrode structure having ion-sensitive material at different levels within the substrate can allow for a higher electrode area density for the structure compared to other electrode configurations.

[0079] Figure 16A An example of an ion-sensitive material 1607 having a surface topology that presents increased surface area, for example, by providing surface texturing or a varied surface topology, is generally shown. Figure 16B A set of non-exclusive shapes of ion-sensitive material that can be exposed in an electrode is shown in plan view. In some examples, certain shapes can allow for increased surface area or increased electrode density compared to other shapes such as described above and below.

[0080] Figure 17A And 17BAn example of a sensor 1700 according to various embodiments of the present subject matter is generally shown. The sensor 1700 can include a substrate 1706 having a plurality of ion sensing electrodes 1701, a mechanical barrier 1729, and a connector 1731 (e.g., coupling the mechanical barrier 1729 with the substrate 1706). In certain examples, the electrodes 1701 can include an ion sensitive material 1707, which can be configured to contact a test substance and provide an indication of a concentration of a particular ion in the substance. In certain examples, the barrier 1729 and the connector 1731 can be positioned to isolate the electrodes 1701 from an external environment, such as an external environment including the test substance. Additionally, the mechanical barrier 1729 can include an opening 1730. The opening 1730 can be rotatable into a plurality of positions in cooperation with the connector 1731. In a first alternative position, the opening 1730 can be positioned to isolate all of the electrodes 1701 from the external environment. In a second position, the opening 1730 can expose one of the electrodes 1701 to the external environment. After a first time interval, the opening 1730 can be rotated or slid to expose a second one of the electrodes 1701 to the external environment. In certain examples, the sensor 1700 can provide a single package that allows a user to monitor changes in ion concentration over time. Furthermore, as the electrodes in use approach the end of their useful life, a new fresh electrode can be easily enabled for sensing.

[0081] Figures 18A-18D Various exemplary configurations of an electrode structure 1800 according to the present subject matter are generally shown. Figure 18A An example of a semiconductor electrode structure 1800 is generally shown. The structure 1800 can include one or more components. As part of a build process to construct the electrode structure 1800, channels 1822 or vias 1821 can be incorporated to enable fluid to flow within or through the electrode structure 1800. Certain examples can include one or more openings or conduits to allow materials such as fluids external to the system to flow to the ion sensitive material 1807 of the electrode 1801, or to inhibit or prevent air or gas from becoming trapped near the electrode 1801. Depending on the target external medium, the channels 1822 can be configured to optimize the path to the ion sensitive material 1807 of the electrode 1801. In certain examples, the channels 1822 in conjunction with the system can be configured in a manner to transport fluids from the external system to the ion sensitive material 1807 of the electrode 1801.

[0082] In certain examples, Figure 18AThe electrode structure 1800 can be a reference electrode. When a sensor including the reference electrode structure 1800 is ready for use, the reference electrode structure can be placed in a vacuum environment to remove any air or other gases from the reference electrode chamber 1834. The reference electrode structure 1800 can then be immersed in a reference material, and the vacuum can be released. Upon release of the vacuum, the reference material can fill the reference electrode chamber 1834 to form a complete reference electrode. Such a structure and method can facilitate long-term storage of a sensor without the risk of contaminating the reference material or some other type of degradation of the reference electrode during storage, as compared to sensors in which the reference material has already been stored in the chamber of the reference electrode.

[0083] Incorporating additional sensing elements, smart circuitry, or passive components within the substrate 1806 can enable a multifunctional sensing system. Examples of added functionality to a sensor can include one or more of a processor, communication circuitry, an inductive coil, or an RFID structure. In one example, a multifunctional sensing system can detect certain ions, analyze ion concentrations, and wirelessly communicate information about the detection of one or more materials, or wirelessly communicate information when a respective threshold level of certain materials is detected by the ion-sensitive material 1807 of the electrode 1801.

[0084] In examples, the structure 1800 can include a first component including processing electronics 1811 and a second component including an electrode for sensing ion concentrations in a target material. In certain examples, the second component can include one or more lateral channels 1822 to provide a passage of the target material to the electrode. In certain examples, the electrode can include an ion-sensitive material 1807, which can be disposed on a conductive trace 1808, for example. In some examples, a cavity 1834 can be located above the sensing element 1807. In some examples, the cavity 1834 or channel located above the sensing element 1807 can contain a gel, a fluid, a filter, or a combination thereof to increase or optimize the sensitivity of the electrode 1801 or the flow to the electrode 1801. In certain examples, the lateral channel 1822 can provide the target material to more than one electrode 1801, as Figure 18B shown. Figure 18B An example of a microfluidic channel 1822 incorporated in an integrated electrode assembly 1800 is generally shown, which includes portions that laterally and vertically pass the target material through the assembly structure. Figure 18C shown. Figure 18C An example of a microfluidic channel 1822 incorporated in an integrated electrode assembly 1800 is generally shown, which includes portions that laterally and vertically pass the target material through the assembly structure.Figure 18A and Figure 18B In each of the examples shown, the microfluidic channel can be fabricated using the layers that make up the integrated electrode 1801. In certain examples, the microfluidic channel 1822 can be fabricated using ceramic, glass reinforced laminates, or one or more other materials suitable for electrical connections as well as the formation of channels or grooves. Figure 18D Examples of semiconductor electrode structures with large openings are shown generally to facilitate more than one electrode 1801. In certain examples, a gel 1826 or filter can be located in the large opening, and each electrode can include a vertical microchannel 1822 or be viaed, such as to allow the gel or target material to contact the ion-sensitive material 1807 of the respective electrode 1801.

[0085] In certain examples, filters, gels, or semi-permeable membranes can be added to the channel 1822 to increase or optimize the efficiency of the sensor. For example, in harsh environments or environments where many contaminants are present, the sensor can be protected from biological contamination by using a filter, gel, semi-permeable membrane, or combination thereof. In certain examples, the filter, gel, or membrane can be specifically constructed to inhibit or prohibit certain materials from entering - thus can be targeted to specific materials. In one example, a filter can be constructed [in addition to mechanical protection] such that only materials of a specific particle or molecular size can permeate through the filter to the sensor.

[0086] In some examples, the system can contain multiple sensors with the ability to use different combinations of filters, gels, and membranes (aimed at optimizing efficiency, and can also be targeted to different external media, such as different gases, pressures and gases, ionic contaminants, etc.). In certain instances, such as those shown, Figures 18A-18C One or more additional microchannels can be employed, such as those shown, to allow gas or air to escape the microchannel that directs the test material.

[0087] Figure 19A and 19BAn example of an ion-sensitive electrode 1901 is generally shown, including a connector 1933 to a target material medium, such as using one or more conduits or tubes 1934. In one example, the ion-sensitive electrode 1901 can include a substrate 1906, an ion-sensitive material 1907, a conductive trace layer 1908, and an optional encapsulation layer 1919 with an opening 1922 to accommodate coupling of the medium to direct a flow of the target material to or from the ion-sensitive material 1907. In some examples, the encapsulation layer material 1919 can include one or more contours or surface features to allow secure fastening of the medium connector 1933 to the opening 1922. In some examples, the encapsulation layer 1919 can include a coupler to allow secure fastening of the medium to be alternatively detached from the encapsulation layer material 1919 at the opening. In some examples, the substrate 1906 can include integrated electronics 1911 for processing signals generated using the ion-sensitive material 1907.

[0088] Figure 20 An example of an ion sensor structure 2000 with multiple sensing electrodes 2001 or elements is generally shown. The ion sensor structure 2000 can include a substrate 2006, processing electronics 2011 integrated with the substrate, and multiple sensing electrodes 2001, where one or more of the electrodes include a passive ion-sensitive material 2007 coupled to a metal trace 2008. In certain examples, each electrode 2001 can be configured to sense a particular ion. In some examples, one or more electrodes 2001 can be configured to sense a first ion, and one or more other electrodes 2001 of the assembly can be configured to sense a second ion. In some examples, a first electrode 2001 of the ion sensor structure 2000 can be configured to sense a first ion at a first concentration range, and a second electrode 2001 of the ion sensor structure 2000 can be configured to sense an ion at a second concentration range. In certain examples, each or any of the electrodes 2001 can be configured to sense ion concentrations according to ion type, ion concentration, pressure of the material, or one or more combinations thereof.

[0089] In certain examples, the electrode structure can include an opening to allow material to enter the passive ion-sensitive material 2007. In some examples, a filter 2023 or gel 2026 can be placed in the opening to regulate particular ions. In certain examples, the opening can include a substrate material with a through-hole or microchannel 2022 to direct material to the passive ion-sensitive material 2007. In some examples, the opening can include a through-hole or microchannel as shown in FIGS. 9A-9F, 10A-10E, 11, and 12. Figure 8A 、 8B

[0090] ​In certain examples, the processing electronics 2011 can include an application specific integrated circuit (ASIC) die to be used with a custom sensing substrate, depending on the particular application. A custom system on a chip can be built using an ASIC, and custom substrates can be mounted on top of the ASIC, which can allow various combinations of sensors, sensor arrays, processing circuitry, discrete components, etc. as needed.

[0091] In certain examples, the ion sensor structure 2000 can optionally include one or more through-silicon vias (TSVs) 2021 within the substrate 2006 or within the second substrate 2034, which can allow the ion sensor structure 2000 to be electrically or mechanically coupled to another package, for example using a coupler, which can include one or more solder balls 2033 or connection pins, for example.

[0092] Figure 21 A cross-sectional view of an example of an electrode structure 2101 for an ion sensor is generally shown. The electrode structure 2101 can include a substrate 2106, an ion-sensitive material 2107, conductive traces 2108, a packaging material 2119, and one or more signal terminals 2112. In certain examples, the ion-sensitive material 2107, the conductive traces 2108, the wiring structure, and the processing electronics 2111 can be integrated with the substrate 2106, for example as shown in other figures of the present application, particularly in Figure 5B In certain examples, the packaging material 2119 can be fabricated to hold the substrate, for example to form a cavity or a via to accommodate or route a target material, and to seal the signal terminals 2112 from an external environment. In certain examples, the cavity or via can be filled with a gel 2126 or a reference material. In certain examples, a seal can be formed in conjunction with a surface of a circuit board 2116 or other device with which the sensor substrate 2106 terminates.

[0093] Figure 22 A cross-sectional view of an example of an electrode structure 2201 and system for an ion sensor is generally shown. The electrode structure 2201 can include a substrate 2206, an ion-sensitive material 2207, conductive traces 2208, a packaging material 2219, and one or more signal terminals 2212. In certain examples, the ion-sensitive material 2207, the conductive traces 2208, and the wiring structure, and the processing electronics 2211 can be integrated with the substrate 2206, for example as shown in other figures of the present application, particularly in Figure 5B In certain examples, the packaging material 2219 can be fabricated to hold the substrate and to form a cavity or a via to accommodate or route a target material. In certain examples, the cavity or via can be filled with a gel 2226 or a reference material.

[0094] In some examples, electrode structure 2201 is configured to provide convenience because it can be easily replaced in an ion sensing system. In some examples, the system may include a sensing element holder, into which the electrode structure can be easily inserted and held. In some examples, sensor element holder 2238 may include circuit board 2216 or other material having one or more mating terminals 2212 and guide housing 2238. Circuit board 2216 or other material may include one or more mating terminals, for example for routing various signals or power to and from electrode structure 2201. Guide housing 2238 may be mechanically coupled to circuit board 2216 or other material and may include end stops 2237. When the electrode structure is inserted into the guide housing, the guide housing may be used to guide the electrode structure on the mating terminals. The end stops may provide mechanical stop for the insertion movement, such that the position of the terminals of the electrode structure is aligned with the mating terminals of the circuit board or other material. In some examples, the mating terminals may be configured to flex during insertion of the electrode structure and apply, for example, a spring force to the terminals of the electrode structure when the electrode structure is fully inserted into the guide housing.

[0095] Figure 23 A cross-sectional view of an exemplary electrode structure and system, such as that used in a diving ion sensor, is shown. The electrode structure may include a substrate 506, an ion-sensitive material, and a packaging material. In some examples, the ion-sensitive material, signal traces and wiring structures, and processing electronics may be integrated with the substrate, as shown in other figures of this application, particularly... Figure 5B As shown in the diagram. In some examples, packaging material may be fabricated to hold the substrate and cavities or vias may be formed to accommodate or guide the target material. In some examples, the cavities or vias may be filled with a gel or reference material. In some examples, instead of having an external terminal from processing electronics to communicate sensor information, the substrate may include an antenna for wirelessly communicating sensor information. In some examples, an accompanying communication device may be placed near the sensor to wirelessly exchange information with it. In some examples, the sensor may include a battery, capacitor, or some other energy storage device to power the electrodes and processing electronics. In some examples, energy may be wirelessly transferred to the sensor. In some examples, the sensor may be placed in locations where one or more wired ion sensors are impractical.

[0096] Figure 24An example sensor structure 2403 is generally shown to help mitigate premature sensor replacement due to channel fouling. The sensor structure 2403 includes a substrate 2406 with a reference electrode 2402 and an indication electrode 2401. The packaging material 2419 or substrate can be formed around the reference electrode 2402 to form a reservoir. In certain examples, the reservoir can contain a gel. The packaging material 2419 can also include a channel 2422 to allow an electrical path to the reference electrode 2402 or reservoir. In certain examples, the channel 2422 can provide multiple openings for the ions to pass through. In applications where the openings of the channel can become blocked by deposits or other solids, this configuration can extend the useful sensing life of the sensor. In certain examples, if one opening becomes fouled or blocked, the electrical path can still pass through the channel via one of the other openings.

[0097] In certain examples, fouling of the sensor can also affect the output impedance of the sensor. In certain examples, the output impedance of the sensor can be measured to detect wear of the sensor. In some examples, active electronics integrated with the substrate 2406 of the sensor can be used to measure the output impedance. In some examples, the output impedance can be measured by a device coupled to the sensor structure.

[0098] Figure 25 An example sensor structure 1503 is generally shown, which includes a temperature sensor 2542. The sensor structure 2503 includes a substrate 2506 with a reference electrode 2502 and an indication electrode 2501. The packaging material 2519 or substrate can be formed around the reference electrode 2502 to form a reservoir. In certain examples, the reservoir can contain a gel. The packaging material 2519 can also include a channel 2522 to allow an electrical path to the reference electrode 2502 or reservoir. In certain examples, the temperature sensor 2542 can include one or more metals that can be cost effectively deposited on the sensor substrate 2506. Many ion concentrations fluctuate with temperature. Having a temperature sensor in close proximity to the target material being sensed can help establish a more accurate determination of ion concentrations within the target material. In certain examples, the temperature sensor 2542 can be unharmed by gamma sterilization. In certain examples, the temperature sensor 2542 can be made using a material whose property changes in response to temperature (e.g., the electrical resistance of the material). In some examples, the temperature sensor 2542 can be made using two or more structures, each structure changing a property in response to temperature such that the ratio of their property values is related to temperature.

[0099] Figure 26A and 26BAn example ion sensor structure 2603 is generally shown, including a portion of resistive material 2643. The sensor structure 2603 includes a substrate 2606 with a reference electrode 2602 and an indicator electrode 2601. An encapsulation material 2619 or substrate can be formed around the reference electrode 2602 to form a reservoir. In certain examples, the reservoir can contain a gel. The encapsulation material 2619 can also include a channel 2622 to allow an electrical path to the reference electrode 2602 or reservoir. In certain examples, the resistive material can be modified or adjusted during a calibration process for the ion sensor. In certain examples, a portion of the resistive material can be ablated using a laser 2644 during a calibration process. Such a configuration allows for on-chip calibration. Additionally, processes such as gamma sterilization do not affect the calibration. In some examples, the resistive material can be trimmed or adjusted by a link that can be selectively blown open. In certain examples, such as the example of FIG. 26B, the resistive material and traces to the resistive material can be configured to allow for a ratiometric calibration. In certain examples, a ratiometric trim can be more robust to process variations and easier to measure. Figure 26C

[0100] Figure 27 An example of a sensor 2703 including an array of indicator electrodes is generally shown. The sensor 2700 can include a single reference electrode 2702, an array 2745 of indicator electrodes 2701, and decoder circuitry 2746, 2747. In certain examples, the reference electrode 2702 can include a structure as described above including a passive ion sensitive material. In certain examples, the reference electrode 2702 can include one or more channels to allow a target material to migrate to or form an electrical connection with a sensing element or material (e.g., a gel) of the reference electrode 2702. The indicator electrodes 2701 of the array 2745 of indicator electrodes can include a structure as discussed in any of the preceding examples. In certain examples, the indicator electrodes 2701 can include a passive ion sensing material and a channel to direct a target material to the passive ion sensing material. In certain examples, the indicator electrodes 2701 do not include an active ion sensing element, such as an ion sensing transistor.

[0101] ​In certain examples, the reference electrode 2702 and the array 2745 of indicating electrodes 2701 can be fabricated on a semiconductor substrate 2706. The decoding circuitry 2746, 2747 associated with the array 2745 of indicating electrodes 2701 can be integrated with the same substrate 2706. For example, on a side of the substrate 2706 other than the side that includes the ion sensing material of the reference electrode 2702 and the ion sensing material of the array 2745 of indicating electrodes 2701. The decoding circuitry 2746, 2747 can include logic for selecting a particular one of the indicating electrodes 2701 and in generating a signal indicative of the state of the selected indicating electrode 2701. In certain examples, each indicating electrode 2701 can be configured to provide information about the same ion. In some examples, each indicating electrode 2701 of the array 2745 of indicating electrodes can be configured to provide information about a different ion. In some examples, more than one of the indicating electrodes 2701 can be configured to provide concentration information about a particular ion. In some examples, an electrode can be configured to provide concentration information for an ion when the ion concentration is within a certain range. In some examples, an electrode can be configured to provide concentration information for an ion when a target material containing the ion is within a certain pressure range.

[0102] Figure 33 Another example of an array sensor 3303 is generally shown. The array sensor 3303 can include a single reference electrode 3302, an array 3345 of indicating electrodes 3301, and decoder circuitry 3346, 3347. In certain examples, the reference electrode 3302 can include a structure as described above, including a passive ion sensitive material. In certain examples, the reference electrode 3302 can include one or more channels to allow target material to migrate to or from electrical connection to the sensing element or material (e.g., gel) of the reference electrode 3302. In certain examples, the indicating electrodes 3301 of the array 3345 of indicating electrodes can include a structure as discussed in any of the preceding examples. In certain examples, the indicating electrodes 3301 can include a passive ion sensing material and a channel to direct target material to the passive ion sensing material. In certain examples, the indicating electrodes 3301 do not include an active ion sensing element, such as an ion sensing transistor.

[0103] In certain examples, for example Figure 33An example array sensor 3303 is shown, indicating that each indicating electrode in the array of electrodes can correspond to one sample well, and that the array of sample wells can correspond to microplate size standards that can be used in automated laboratory analysis systems. Such microplate size standards can include, but are not limited to, ANSI SLAS 4-2004 (R2012) (formerly ANSI / SBS 4-2004), "Positioning for Microplates" (October 13, 2011) and updates thereto. Such an array sensor 3303 can allow for simultaneous sampling or measurement of multiple individual samples. In certain examples, each indicating electrode 3301 can be associated with a dedicated channel 3322 that couples the well of the indicating electrode 3301 with the reference material of the reference electrode 3302. Such an example can allow for measurement of many individual samples for ion concentrations indicated by the ion-sensitive material of each indicating electrode 3301 and the configuration of the reference electrode 3302 and reference material.

[0104] In certain examples, the array 3345 of reference electrodes 3302 and indicating electrodes 3301 can be fabricated on a semiconductor substrate 3306. Decoding circuitry 3346, 3347 associated with the array 3345 of indicating electrodes 3301 can be integrated with the same substrate 3306. In some examples, the decoding circuitry, such as multiplexers, can be located on a side of the substrate 3306 other than the side of the substrate 3306 on which the ion- sensing material of the array 3345 of indicating electrodes 3301 and the ion-sensing material of the reference electrode 3302 are located. In some examples, the decoding circuitry can be located on the same side of the substrate as the ion-sensing material, and can be protected from the reference material or target material, for example, by an oxide layer. The decoding circuitry 3346, 3347 can include logic, such as multiplexers, for selecting a particular one of the indicating electrodes 3301 and in generating a signal indicative of the state of the selected indicating electrode 3301. In certain examples, each indicating electrode 3301 can be configured to provide information about the same ion.

[0105] Figure 28An example of a sensor probe 2803 with an impedance sensor 2848 is generally shown. As discussed above with respect to multiple examples, in addition to electrodes 2801, 2802 for sensing ions or ion concentrations, a sensor structure or probe 2803 can include other sensors. In certain examples, a sensor probe 2803 can include an impedance sensor 2848. In certain examples, an impedance sensor 2848 can provide an indication as to when a sensor probe 2803 is in contact with a material, such as a target liquid. Additionally, an impedance sensor 2848 with an appropriate layout can provide an indication as to whether there is a sufficient amount of target material available to, for example, cover an electrode and allow for an appropriate ion concentration measurement to be made. In general, an impedance sensor 2848 can provide an indication of the total concentration of ions in a liquid, as opposed to an ion sensing electrode which provides an indication of the concentration of a particular ion in a liquid.

[0106] Figure 29A and 29B An example of a sensor structure 2900 or probe is generally shown, including a shield 2949 for protecting an electrode. As described above, each electrode in an electrode structure provides a voltage that can be processed to provide an indication of ion concentration. However, the signal directly produced by each electrode can be susceptible to interference such as electromagnetic interference. Figure 29A An electrode structure 2900 is generally shown, including a shield 2949 over a through hole 2922 to a passive ion sensitive material 2907 of an electrode. In certain examples, a shield 2949 can seal a through hole 2922. In such examples, a shield 2949 can be porous to allow a target material 2910 to contact a sensing element of an electrode. A shield 2949 can include a conductive material for interrupting electromagnetic interference near an electrode. In certain examples, a shield 2949 can be coupled to a ground or a reference terminal of a battery of an electrode structure 2900. In some examples, an electrode structure 2900 can provide a conductive path to ground a shield. Figure 29B An example of a shield 2949 is generally shown, which can be coupled to an encapsulation material 2919 of, for example, an electrode structure 2900 using standoffs 2950 to allow a target material 2910 to pass under a shield 2949 to a through hole 2922. In such examples, a shield 2949 can be non-porous. In certain examples, an electrode structure can optionally include a substrate 2906, an encapsulation material 2919, electronics 2911 integrated with a substrate 2906, a circuit board 2939, a reference material 2910, or a combination thereof.

[0107] In certain examples, the shroud 2949 can include a light barrier. Light can sometimes affect the performance of the electrode, and in certain cases, light can shorten the useful life of the electrode compared to an electrode that is not exposed to ambient light. In certain examples, the electrode structure 2900 can include a light barrier coupled to the encapsulation material 2919 forming the through hole 2922. In some examples, the electrode structure 2900 can include a light barrier coupled to the encapsulation material 2919 using a bracket 2950, so the target material or reference material 2910 can contact the through hole 2922 and form an electrical circuit with the sensing element of the electrode, such as a gel or a passive ion sensing element 2907 of the electrode.

[0108] Figure 30 Generally shown is a substrate 3006 including a plurality of sensor structures 3001 that can allow for extended operation. Extended operation can be performed using addressable or sequentially activated electrodes. In certain examples, when a first electrode structure reaches the end of its useful sensing life, a second electrode structure can be activated by, for example, piercing or rupturing the membrane of the electrode structure.

[0109] Figure 31 Generally shown is a substrate 3006 including a plurality of sensor structures 3001 that can allow for extended operation. Extended operation can be performed using addressable or sequentially activated electrodes. In certain examples, when a first electrode structure reaches the end of its useful sensing life, a second electrode structure can be activated by, for example, piercing or rupturing the membrane of the electrode structure. Figure 30An example of an electrode structure 3101 of a sensor of a portion of a system shown in FIG. 3. The electrode structure can include a substrate 3106, an active electronic device 3111 integrated with the substrate 3106, an ion-sensitive material 3107, a conductive trace 3108 connecting the ion-sensitive material 3107 with the active electronic device 3111, an additional substrate material or encapsulation material 3129, and a membrane 3140. The membrane 3140 can isolate a target material or other material from the ion-sensitive material 3107. The membrane can include electrical connections 3141, 3142 to the active electronic device. In certain examples, heat can be used to pop or puncture the membrane. In certain examples, a heating element in contact with or immediately adjacent to the membrane 3140 can be activated to rupture the membrane 3140 via heat. In certain examples, the heating element can be integrated with the membrane 3140 such that when the electrode structure 3101 is selected for active sensing use, the heating element can be activated via the electrical connections 3141, 3142 and can rupture the membrane 3140, allowing the target material to contact the ion-sensitive material 3107. In some examples, the membrane 3140 can include a piezoelectric material. When the electrode structure 3101 is selected for active sensing use, the piezoelectric can be activated via the electrical connections 3141, 3142 and can, for example, vibrate to rupture the membrane 3140, allowing the target material to enter the ion-sensitive material 3107. For example, the sensor can include a selection circuit that can rupture the next septum in sequence each time a single input of the selection circuit is activated for a minimum time period, where the minimum time period represents a maximum time required for a typical heating element or piezoelectric device to rupture a respective membrane of the sensor structure. In certain examples, piezoelectric material can also be used to prevent or eliminate fouling of the electrode structure.

[0110] Figure 32 A flowchart generally showing an example of a method 3200 for operating a device including a passive ion-sensitive electrode is shown. At 3201, a test material can be directed to the passive ion-sensitive electrode using a channel integrated within the same substrate as the passive ion-sensitive electrode. In certain examples, the test material can be directed using a microchannel of the substrate that also houses the passive ion-sensitive electrode. In some examples, the microchannel can direct the test material laterally through the substrate to the passive ion-sensitive electrode. In certain examples, the microchannel can direct the test material vertically through the substrate to the passive ion-sensitive electrode. In some examples, the substrate can include a combination of microchannels to direct the test material to the passive ion-sensitive electrode. In certain examples, the substrate can include stacked layers, and the stacked layers can include microchannels that, when stacked, direct the test material to the passive ion-sensitive electrode.

[0111] In certain examples, a substrate can include a via over a passive ion-sensitive electrode to direct test material to the passive ion-sensitive electrode. In some examples, the via can include a gel or filter. In some examples, a substrate can include a plurality of passive ion-sensitive electrodes supported by vias or microchannels for directing test material to the passive ion-sensitive electrodes.

[0112] In certain examples, a system can be used to selectively direct test material to a passive ion-sensitive electrode. In some examples, a substrate can include a plurality of passive ion-sensitive electrodes. A selection device can be coupled to the substrate. The selection device can include an opening and can be positioned to direct test material onto one of the plurality of passive ion-sensitive electrodes. The mechanism can cover the test material and isolate it from other previously unselected passive ion-sensitive electrodes of the plurality. Such a device can be immersed in a test material or solution and can provide measurement information for long periods of time compared to sensors with a single indicator electrode. In certain examples, a substrate can include a plurality of passive ion-sensitive electrodes and a membrane over one or more passive ion-sensitive electrodes can be used to select an electrode or a set of electrodes for measuring a test material or solution. In some examples, rupturing the membrane can select or activate an electrode for providing measurement information. In certain examples, a heating element adjacent to or integrated with the membrane can be used to electronically rupture the membrane. Such a mechanism or system can allow an active electronic device integrated with a substrate including a plurality of passive ion-sensitive electrodes to monitor a parameter and automatically select an electrode or a set of electrodes to provide measurement information. In certain examples, the parameter can include a parameter related to a characteristic of the test material, such as concentration, pressure, temperature, etc. In certain examples, the parameter can include a parameter associated with a current active electrode, such as a measurement quality parameter, an active measurement lifetime of a currently active sensor, etc.

[0113] At 3203, sensing information for a passive ion-sensitive electrode can be received at an active electronic device integrated with the substrate. Receiving sensing information from one or more passive ion-sensitive electrodes (such as a combination of the indicator electrode and the reference electrode described above) at an electronic device integrated with the same substrate can reduce or eliminate interference issues associated with conventional ion sensing devices. Additionally, the sensor can be very small, can be submersible, can be inexpensive, and can provide robust performance in a variety of environments including harsh environments that do not use certain conventional expensive equipment.

[0114] At 3205, an indication of an ion concentration of the test material can be provided as an output of the active electronic device. In certain examples, the sensing information can be processed by the active electronic device of the substrate and ion concentration information, as well as other information, can be provided via a wired or wireless medium. In certain examples, the indication can be an analog signal, a digital signal, or a combination of analog and digital signals.

[0115] The measurement data (e.g., specific values / readings / thresholds, etc.) generated by the microfluidic system can be encrypted to protect the integrity or functional safety of the system. In certain examples, the encryption can be accomplished by processing electronics integrated on a substrate of an electrode of the sensor. The encryption can be accomplished by software, firmware, or hardware to ensure that the measurement information is not compromised at the sensor or during transmission of data from the sensor.

[0116] Various notes & examples

[0117] In Aspect 1, an integrated ion-sensitive probe device for sensing a concentration of a material without requiring an active electrode can include: a semiconductor substrate; a first passive electrode integrated with the semiconductor substrate and configured to contact a solution and provide a first voltage that is a function of a concentration of an ion in the solution; and a channel configured to direct the solution to the first passive electrode.

[0118] In Aspect 2, the channel of Aspect 1 optionally includes an opening in the substrate, and the first passive electrode is located at a bottom surface of the opening.

[0119] In Aspect 3, a sidewall surface of the channel of any one or more of Aspects 1-2 is optionally sloped from an upper surface of the semiconductor substrate toward the first passive electrode.

[0120] In Aspect 4, a sidewall surface of the channel of any one or more of Aspects 1-3 is optionally stepped from an upper surface of the semiconductor substrate toward the first passive electrode.

[0121] In Aspect 5, the channel of any one or more of Aspects 1-4 optionally includes a first microchannel configured to conduct the solution to the first passive electrode.

[0122] In Aspect 6, the substrate of any one or more of Aspects 1-5 optionally includes a plurality of second microchannels coupled with the first microchannel, the plurality of second microchannels configured to allow operation of the device when one of the second microchannels is contaminated.

[0123] In Aspect 7, the first passive electrode of any one or more of Aspects 1-6 is optionally located in a first plane, and the first microchannel of any one or more of Aspects 1-6 is optionally configured to direct the solution within the substrate parallel to the first plane.

[0124] In Aspect 8, the first microchannel of any one or more of Aspects 1-7 is optionally extended a length through the substrate, and the first microchannel within the substrate is open along the length.

[0125] In Aspect 9, the device of any one or more of Aspects 1-7 optionally includes a cover configured to enclose the first microchannel along the length.

[0126] In Aspect 10, the first passive electrode of any one or more of Aspects 1-9 is optionally located in a first plane, and the first microchannel of any one or more of Aspects 1-9 is optionally configured to direct the solution within the substrate perpendicular to the first plane.

[0127] In Aspect 11, the substrate of any one or more of Aspects 1-10 optionally includes a thermal device located proximate to the first microchannel.

[0128] In Aspect 12, the substrate of any one or more of Aspects 1-11 optionally includes a magnetic device located proximate to the first microchannel.

[0129] In Aspect 13, the substrate of any one or more of Aspects 1-12 optionally includes a second microchannel, wherein the second microchannel intersects the first microchannel.

[0130] In Aspect 14, the device of any one or more of Aspects 1-13 optionally includes a filter inserted within the second microchannel.

[0131] In Aspect 15, the device of any one or more of Aspects 1-14 optionally includes a gel inserted within the second microchannel.

[0132] In Aspect 16, the first passive electrode of any one or more of Aspects 1-15 is optionally located in a first plane of the substrate, and the device includes a second passive electrode located in a second plane of the substrate, the second plane being parallel to the first plane.

[0133] In Aspect 17, the second plane of any one or more of Aspects 1-16 is optionally at a different depth within the substrate.

[0134] In Aspect 18, the substrate of one or more of Aspects 1-17 optionally includes a microchannel configured to conduct the solution to the first passive electrode and the second passive electrode.

[0135] In Aspect 19, the substrate of any one or more of Aspects 1-18 optionally includes external electrical interconnections.

[0136] In Aspect 20, the device of any one or more of Aspects 1-19 optionally includes a circuit board for routing electrical signals to and from the device via the external electrical interconnections of the substrate and mating electrical interconnections of the circuit board.

[0137] In Aspect 21, the apparatus of any one or more of Aspects 1-20 can optionally include a guide housing having an end stop, the guide housing mounted to the circuit board and configured to guide positioning of the semiconductor substrate upon insertion of the substrate into the guide housing and from the guide housing, and wherein the end stop is configured to reference the substrate and align external electrical interconnects of the substrate with mating electrical interconnects of the circuit board after insertion of the substrate into the guide housing.

[0138] In Aspect 22, the apparatus of one or more of Aspects 1-21 can optionally include a shield over the first passive electrode.

[0139] In Aspect 23, the apparatus of any one or more of Aspects 1-22 can optionally include a standoff configured to allow passage of a target material under the shield to the first passive electrode.

[0140] In Aspect 24, the shield of any one or more of Aspects 1-23 can optionally be an electromagnetic shield.

[0141] In Aspect 25, the shield of any one or more of Aspects 1-24 can optionally be a light shield.

[0142] In Aspect 26, the shield of any one or more of Aspects 1-25 can optionally be porous.

[0143] In Aspect 27, the shield of any one or more of Aspects 1-26 can optionally be configured to isolate the target material from contact with the first passive electrode.

[0144] In Aspect 28, the apparatus of any one or more of Aspects 1-27 can optionally include a device coupled to an integrated circuit of the substrate, the device configured to break the shield.

[0145] In Aspect 29, the apparatus of any one or more of Aspects 1-28 can optionally include a heating device.

[0146] In Aspect 30, the apparatus of one or more of Aspects 1-29 can optionally include a piezoelectric device.

[0147] In Aspect 31, the apparatus of one or more of Aspects 1-30 can optionally include an integrated circuit fabricated on the substrate, the integrated circuit configured to buffer a signal provided by the first passive electrode.

[0148] In Aspect 32, the apparatus of one or more of Aspects 1-31 can optionally include a temperature sensor integrated on the substrate and coupled to the integrated circuit.

[0149] In aspect 33, the apparatus of any one or more of aspects 1-32 optionally includes a pressure sensor integrated on the substrate and coupled to the integrated circuit.

[0150] In aspect 34, the apparatus of one or more of aspects 1-33 optionally includes a resistance calibration circuit integrated on the substrate and coupled to the integrated circuit.

[0151] In aspect 35, the resistive material of any one or more of aspects 1-34 is optionally configured for ratio metric calibration trimming.

[0152] In aspect 36, the apparatus of any one or more of aspects 1-35 optionally includes a blowable linkage to adjust the resistance calibration circuit.

[0153] In aspect 37, an apparatus can include a substrate; and a plurality of ion-sensitive electrode structures fabricated on the substrate, wherein one or more of the plurality of ion-sensitive structures includes a passive ion-sensitive electrode configured to contact a solution and provide a first voltage as a function of ion concentration in the solution. The apparatus can be configured for sensing a concentration of a material without an active electrode.

[0154] In aspect 38, the apparatus of one or more of aspects 1-37 optionally includes a shield having an opening configured to isolate a solution from at least a subset of the plurality of ion-sensitive electrodes, the opening configured to allow the solution to contact one of the plurality of ion-sensitive electrodes when the opening is positioned over the one ion-sensitive electrode.

[0155] In aspect 39, the shield of any one or more of aspects 1-38 is optionally anchored to the substrate.

[0156] In aspect 40, the shield of any one or more of aspects 1-39 is optionally configured to rotate about the anchor to allow the opening to selectively access one of the plurality of ion-sensitive electrodes.

[0157] In aspect 41, the plurality of ion-sensitive electrode structures of any one or more of aspects 1-40 are optionally arranged in an array, and the apparatus of any one or more of aspects 1-40 optionally includes a decoder circuit integrated with the substrate, wherein the decoder circuit is configured to route the first voltage of a particular one of the plurality of ion-sensitive electrode structures to the processing circuit.

[0158] In aspect 42, the decoder circuit of any one or more of aspects 1-41 is optionally configured to receive selection information from the processing circuit, and in response to the selection information, communicate the first voltage of a particular one of the plurality of ion-sensitive electrode structures to the processing circuit.

[0159] In aspect 43, a method of operating an integrated sensor device to detect a concentration of a material without requiring an active electrode can include directing the material to a passive ion-sensitive electrode through a channel of a substrate that includes the passive ion-sensitive electrode, receiving sensing information from the passive ion-sensitive electrode on an active electronic device integrated with the substrate, and indicating an ion concentration of the material using the active electronic device.

[0160] In aspect 44, the directing of the material into the passive ion-sensitive electrode of any one or more of aspects 1-43 can optionally include rotating an opening of a shield over the passive ion-sensitive electrode.

[0161] In aspect 45, the passive ion-sensitive electrode of any one or more of aspects 1-44 can optionally be one of an array of passive ion-sensitive electrodes, and the receiving of sensing information from the passive ion-sensitive electrode of any one or more of aspects 1-44 can optionally include receiving selection information at a decoder of the active electronic device and, in response to the selection information, routing the sensing information to the active electronic device via the decoder.

[0162] In aspect 46, the method of any one or more of aspects 1-45 can optionally include receiving temperature information at the active electronic device from a temperature sensor integrated with the substrate.

[0163] In aspect 47, the method of any one or more of aspects 1-35 can optionally include calibrating the active electronic device using a calibration resistor integrated with the substrate, wherein the calibrating includes adjusting the calibration resistor.

[0164] In aspect 48, the adjusting of the calibration resistor of any one or more of aspects 1-47 can optionally include laser trimming a portion of the calibration resistor.

[0165] In aspect 49, the directing of the material of any one or more of aspects 1-48 can optionally include rupturing a membrane that isolates the material from the passive ion-sensitive electrode.

[0166] In aspect 50, the rupturing of the membrane of any one or more of aspects 1-49 can optionally include activating a heating element proximate the membrane.

[0167] In aspect 51, the membrane that is ruptured of any one or more of aspects 1-50 can optionally include a piezoelectric element that electrically energizes the membrane.

[0168] In aspect 52, the directing of the material of any one or more of aspects 1-51 can optionally include directing the material to the passive ion-sensitive electrode via a microchannel of the substrate.

[0169] In aspect 53, the directing of the material of any one or more of aspects 1-52 can optionally include using a device located proximate the microchannel to condition the material.

[0170] In aspect 54, conditioning the material of any one or more of aspects 1-53 includes applying magnetic energy to the material using a magnetic device positioned proximate the microchannel.

[0171] In aspect 55, conditioning the material of any one or more of aspects 1-54 includes optionally including exchanging thermal energy with the material using a thermal device positioned proximate the microchannel.

[0172] In aspect 56, the thermal device of any one or more of aspects 1-55 optionally includes a heater.

[0173] In aspect 57, providing the indication of any one or more of aspects 1-56 optionally includes amplifying the signal received from the passive ion-sensitive electrode at an amplifier of an active electronic device.

[0174] In aspect 58, providing the indication includes wirelessly communicating the indication from the substrate including the passive ion-sensitive electrode.

[0175] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the application can be practiced. These embodiments are also referred to as "examples." Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0176] To the extent usage of terms does not naturally correspond with the way they are used in any document incorporated herein by reference, the usage in this document controls.

[0177] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "comprising" are used as the plain-English equivalents of the respective terms "including" and "comprising." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0178] Method examples described herein can be machine or computer- implemented at least in part. Some examples can include a computer- readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level languages code, or the like. Such code can include computer readable instructions for performing various methods. The code can form portions of computer program products. Further, in an example, the code can be tangibly embodied on one or more volatile or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media can include, but are not limited to, hard disk drives, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, RAM, ROM, etc.

[0179] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be apparent to those of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b) to allow a reader to quickly ascertain the nature of the technical disclosure. It is understood that it is not intended to be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed feature is essential to any claim. Rather, inventive subject matter can lie in fewer than all features of a particular disclosed embodiment. Accordingly, the following claims, as they can be amended during the prosecution process, are hereby incorporated into this Detailed Description, by reference, as examples or embodiments, and the claims can be combined with one another in various ways. The scope of the application should be determined with reference to the appended claims and the full scope of equivalents to which they are entitled.

Claims

1. An integrated ion-sensitive probe device for sensing the concentration of a material, the device comprising: substrate; A first electrode, in communication with the substrate and configured to contact the solution and provide a first voltage, the first voltage being a function of the concentration of ions in the solution; A cavity is configured to expose the solution to the first electrode; as well as The reference electrode structure includes: Second electrode; The container is configured to maintain contact between the reference material and the second electrode; and The container includes a barrier configured to at least partially seal the reference material within the container, and a portion of the container provides an electrical interface between the reference material and the solution.

2. The device of claim 1 further includes an active electronic device communicating with the substrate, the active electronic device including an antenna configured to wirelessly transmit sensor data from the ion-sensitive probe device.

3. The device of claim 2, further comprising a battery configured to power the ion-sensitive probe device.

4. The device of claim 2, further comprising a channel configured to direct the solution to the first electrode.

5. The device according to claim 4, wherein, The channel includes at least one of a filter, a semi-permeable membrane, a magnetic element, a heating element, or a piezoelectric element configured to reduce fouling in the channel.

6. The device of claim 1 further includes a temperature sensor comprising at least two materials, each of the at least two materials having material properties responsive to temperature changes such that the ratio of their material properties depends on temperature.

7. The device according to claim 6, wherein, The material properties include electrical resistance.

8. The device according to claim 2, wherein, The first electrode is a first indicator electrode, and the device includes a plurality of additional indicator electrodes arranged in an array with the first indicator electrode to form an array of indicator electrodes.

9. The device according to claim 8, wherein, The active electronic device includes a decoder circuit containing logic to selectively couple one of the indicator electrodes of the array to the processing path of the device.

10. The device of claim 1, further comprising an active electronic device configured to encrypt sensor data from the ion-sensitive probe device.

11. The device of claim 1, further comprising an active electronic device integrated with the substrate, the active electronic device being configured to detect output impedance and determine scaling condition at least in part based on the detected output impedance.

12. The device of claim 1, further comprising at least one vertical channel and one lateral channel configured to guide the solution to the first electrode.

13. The device according to claim 12, wherein, At least one of the vertical channel and the horizontal channel includes an adjustment element.

14. The device according to claim 13, wherein, The regulating element includes a thermal element configured to heat or cool at least a portion of a vertical or horizontal channel.

15. The device according to claim 13, wherein, The regulating element includes a magnet.

16. The device according to claim 13, wherein, The regulating element includes a microelectromechanical system configured to vibrate in order to reduce fouling.

17. The device according to claim 16, wherein, The microelectromechanical system includes at least one of an actuator, a moving part, a rotating part, and a movable beam.

18. The device according to claim 13, wherein, The regulating element includes a piezoelectric material.

19. The device according to claim 13, wherein, The adjustment element is positioned adjacent to the opening of the vertical or horizontal channel.

20. The device according to claim 13, wherein, The adjustment element extends at least partially through the length of the vertical or horizontal channel.

21. The device according to claim 13, wherein, The adjustment element is positioned on the substrate.

22. The device according to claim 13, wherein, The adjustment element is positioned on the cover, which is configured to close the transverse channel.

23. A method of operating a sensor device, the method comprising: Material is exposed to an ion-sensitive electrode via a cavity in a substrate, the substrate including the ion-sensitive electrode; Sensing information is received from the ion-sensitive electrode at an active electronic device that communicates with the substrate; The active electronic device is used to provide an indication of the ion concentration of the material; Use a temperature device to monitor or adjust the temperature of the material, or use a temperature device to monitor and adjust the temperature of the material. The reference material is contained within a container integrated with the substrate; Expose the reference material to the reference electrode; as well as An electrical connection or interface is established between the ion-sensitive electrode and the reference electrode using a portion of the container; The portion of the container used to establish an electrical connection or interface between the ion-sensitive electrode and the reference electrode includes a barrier configured to at least partially seal the reference material within the container.

24. The method according to claim 23, wherein, Exposing the material to the ion-sensitive electrode includes rotating the opening of the shield above the ion-sensitive electrode.

25. The method according to claim 23, wherein, The ion-sensitive electrode is one of an array of ion-sensitive electrodes; and Receiving sensing information from the ion-sensitive electrode includes: receiving selection information at the decoder of the active electronic device, and in response to the selection information, routing the sensing information to the active electronic device via the decoder.

26. The method of claim 23, further comprising calibrating the active electronic device using a calibration resistor integrated with the substrate, wherein the calibration includes adjusting the calibration resistor.

27. The method according to claim 23, wherein, Exposing the material includes guiding the material to the ion-sensitive electrode via channels in the substrate.

28. The method according to claim 27, wherein, The guiding material includes rupture of the diaphragm that isolates the material from the ion-sensitive electrode.

29. The method according to claim 28, wherein, The rupture of the diaphragm includes electrically actuating the piezoelectric element of the diaphragm.

30. The method according to claim 27, wherein, Guiding the material includes guiding the material to the ion-sensitive electrode via microchannels in the substrate.

31. An integrated ion-sensitive probe device for sensing the concentration of a material without requiring an active electrode, the device comprising: substrate; A plurality of first electrodes, each first electrode communicating with the substrate and configured to contact the solution and provide a first voltage, the first voltage being a function of the concentration of ions in the solution; A channel is configured to guide the solution to the first electrode; Including mechanical barriers with openings, and A connector that couples the mechanical barrier to the substrate; The mechanical barrier and the connector are positioned to isolate the first electrode from the external environment, and the opening rotates in conjunction with the connector to expose a selected first electrode from the plurality of first electrodes to the external environment.

32. The device according to claim 31, wherein, The channel includes a first microchannel configured to conduct the solution to the first electrode.

33. The device according to claim 32, wherein, The substrate includes a plurality of second microchannels coupled to the first microchannel, the plurality of second microchannels being configured to allow device operation when one of the second microchannels becomes fouled.

34. The device according to claim 32, wherein, The first electrode is located in a first plane; and wherein the first microchannel is configured to conduct the solution within the substrate parallel to the first plane.

35. The device according to claim 34, wherein, The first microchannel extends through the substrate for a certain length, and the first microchannel within the substrate opens along the length, and the device includes a cap configured to close the first microchannel along the length.

36. The device according to claim 32, wherein, The first electrode is located in a first plane; and wherein the first microchannel is configured to conduct the solution within the substrate perpendicular to the first plane.

37. The device according to claim 31, wherein, The channel includes at least one of a filter, a semi-permeable membrane, a magnetic element, a heating element, or a piezoelectric element.

38. The device according to claim 31, wherein, The first electrode is a first indicating electrode, and the device includes a reference electrode structure comprising: Second electrode; A container is configured to receive a reference material and maintain the reference material in contact with the second electrode; and At least one microchannel is configured to establish an ion exchange interface between a reference material in the container and a target material in contact with the first indicating electrode.

39. The device of claim 38, further comprising one or more additional indicating electrodes.

40. The device according to claim 31, wherein, The first electrode is a first indicator electrode, and the device includes a plurality of additional electrodes arranged in an array with the first indicator electrode to form an array of indicator electrodes.

41. The device of claim 40, further comprising a reference electrode structure, the reference electrode structure comprising: Second electrode; The container is configured to receive a reference material and maintain the reference material in contact with a second ion-sensitive reference electrode; And at least one microchannel, configured to establish an ion exchange interface between a reference material in the container and a target material in contact with the first indicator electrode or at least one of a plurality of additional indicator electrodes.

42. The device of claim 41, further comprising logic for selectively coupling one of the indicator electrodes of the array to a processing path of the device.

43. The device according to claim 31, wherein, The first electrode is a reference electrode and the solution is a reference solution.

44. The device according to claim 31, wherein, The first electrode is an indicating electrode and the device includes a reference electrode structure, wherein the reference electrode structure comprises: A second electrode communicating with the substrate; a container configured to keep a reference material in contact with the second electrode; and The container includes a diaphragm configured to allow a needle to penetrate the diaphragm to fill the container with the reference material, and to reseal the container when the needle is withdrawn from the diaphragm.

45. The device according to claim 44, wherein, The diaphragm provides an electrical interface between the reference material and the solution.

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