Sensing system with layered microprobe

Abstract

The sensing system includes a microprobe, the microprobe comprising a layered structure and an encapsulant. The layered structure includes a sensing unit, a deformable layer, a ductile layer, and a sensor interface layer. The sensing unit includes a sensor having a working electrode, a first outer periphery when viewed in the stacking direction, a first material having a first material toughness, and a first surface and a second surface. The deformable layer is configured to deform under stress and is positioned on the first surface of the sensing unit. The ductile layer is positioned on the deformable layer on the side opposite the sensing unit, a second outer periphery when viewed in the stacking direction, the first outer periphery nested within the second outer periphery, and the second material having a second material toughness greater than the first material toughness. The sensor interface layer is positioned on the second surface of the sensing unit. The encapsulant partially encapsulates the layered structure, mechanically isolating the layered structure from the surrounding environment.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application is related to and claims the benefit of commonly owned, co-pending U.S. Provisional Application No. 62 / 962,677, filed January 17, 2020, and entitled "SENSING SYSTEM WITH LAYERED MICROPROBE," the contents of which are incorporated herein by reference in their entirety.

[0002] [Field] The present disclosure relates to sensing and sensing systems comprising one or more layered microprobes or microneedles, and related methods. [Background technology]

[0003] Microsensing systems, such as sensors mounted on microneedles, microprobes, or neural probes, are commonly used in biological and other applications. Summary of the Invention

[0004] This Summary is a high level overview of various aspects of the invention and introduces certain concepts that are described in more detail in the Detailed Description section below. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used alone to determine the scope of the claimed subject matter. The claimed subject matter should be understood by reference to the entire specification, any or all drawings, and appropriate portions of each claim.

[0005] An embodiment of the present disclosure relates to a sensing system comprising at least one microprobe. The microprobe comprises a layered structure including a sensing unit having at least one sensor. The at least one sensor includes a working electrode, the sensing unit has a first periphery when viewed in a stacking direction of the layered structure, the sensing unit includes a first material having a first material toughness, and the sensing unit has a first surface and a second surface opposite to the first surface. The layered structure further comprises a deformable layer disposed on the first surface of the sensing unit. The deformable layer is configured to deform under stress. The layered structure further comprises a ductile layer disposed on the deformable layer opposite to the sensing unit. The ductile layer has a second periphery when viewed in a stacking direction of the layered structure. The first periphery is completely within the second periphery. The ductile layer includes a second material having a second material toughness greater than the first material toughness. The deformable layer is also configured to couple the sensing unit to the ductile layer and partially transfer strain resulting from stress applied to the sensing unit to the ductile layer. The layered structure further comprises a sensor interface layer disposed on the second surface of the sensing unit. The microprobe further comprises at least one encapsulant. The at least one encapsulant at least partially encapsulates the layered structure. The at least one encapsulant is configured to isolate the layered structure from an ambient environment.

[0006] In some embodiments, the encapsulant is configured to contain (contain) debris from at least one of the first material, the second material, a material of the deformable layer, or a material of a sensor interface.

[0007] In some embodiments, the encapsulant is at least one of chemically inert, biocompatible, biodegradable, stain resistant, hydrophobic, or hydrophilic.

[0008] In some embodiments, the encapsulant is configured to mechanically isolate the layered structure from the ambient environment.

[0009] In some embodiments, the encapsulant is configured to electrically insulate (isolate) the layered structure from the surrounding environment.

[0010] In some embodiments, the encapsulant has a thickness in the range of 100 nanometers to 200 microns.

[0011] In some embodiments, the encapsulant comprises an opening that is open to the sensor interface layer.

[0012] In some embodiments, the opening is covered or filled with a hydrogel configured to expand in volume upon contact with a liquid.

[0013] In some embodiments, the encapsulant completely encapsulates the layered structure.

[0014] In some embodiments, at least a portion of the tip of the sensing unit is unencapsulated.

[0015] In some embodiments, the encapsulant comprises polyamide, parylene, polyurethane, or a combination thereof.

[0016] In some embodiments, the sensor interface layer is at least one of chemically inert, biocompatible, biodegradable, anti-fouling, hydrophobic, or hydrophilic.

[0017] In some embodiments, the sensor interface layer has a thickness in the range of 10 nanometers to 200 microns.

[0018] In some embodiments, the sensor interface layer comprises a hydrogel.

[0019] In some embodiments, the deformable layer is an adhesive.

[0020] In some embodiments, the deformable layer comprises polyacrylate, polyamide, SU-8, polymethylmethacrylate, parylene, epoxy resin, silicone resin, or a combination thereof.

[0021] In some embodiments, the deformable layer is reinforced with aluminum oxide, silicon oxide, silicon oxynitride, or a combination thereof.

[0022] In some embodiments, the deformable layer has a thickness in the range of 1 micron to 100 microns.

[0023] In some embodiments, the sensing unit is adhered to the ductile layer via a multi-layer structure (layered structure) having a first adhesive, a deformable material (the material of the deformable layer), and a second adhesive.

[0024] In some embodiments, the thickness of the deformable layer is less than the surface roughness of each of the sensing unit and the ductile layer.

[0025] In some embodiments, the deformable layer electrically insulates the sensing unit from the ductile layer.

[0026] In some embodiments, at least one of the sensing unit and the ductile layer is encapsulated by an oxide, a metal oxide, a native oxide, a polymer, or a combination thereof.

[0027] In some embodiments, the ductile layer includes, for example, stainless steel, cobalt, titanium, aluminum, nickel, chromium, molybdenum, tungsten, and alloys thereof.

[0028] In some embodiments, the ductile layer comprises a recess in a surface adjacent the sensing unit, the sensing unit being received within and at least partially surrounded by the recess.

[0029] In some embodiments, a depth of the recess is equal to a dimension between a first surface of the sensing unit adjacent to the ductile layer and a second surface of the sensing unit opposite the first surface.

[0030] In some embodiments, the depth of the recess is greater than the dimension between a first surface of the sensing unit adjacent to the ductile layer and a second surface of the sensing unit opposite the first surface.

[0031] In some embodiments, the depth of the recess is less than the dimension between a first surface of the sensing unit adjacent to the ductile layer and a second surface of the sensing unit opposite the first surface.

[0032] In some embodiments, the sensing unit comprises a shaft and a tip.

[0033] In some embodiments, the ductile layer comprises a shaft and a tip.

[0034] In some embodiments, the tip of the ductile layer protrudes beyond the tip of the sensing unit such that the ductile layer is configured to absorb axial insertion forces applied during use.

[0035] An embodiment of the present disclosure also relates to a microprobe with a layered structure. The layered structure includes a sensing unit having at least one sensor, the at least one sensor having a working electrode, the sensing unit having a first periphery when viewed in a stacking direction of the layered structure, the sensing unit including a first material having a first material toughness, the sensing unit having a first surface and a second surface opposite the first surface. The layered structure further includes a deformable layer positioned on the first surface of the sensing unit, the deformable layer configured to deform under stress. The layered structure further includes a ductile layer positioned on the deformable layer on the side opposite the sensing unit. The ductile layer has a second periphery when viewed in a stacking direction of the layered structure. The first periphery is completely contained within the second periphery. The ductile layer includes a second material having a second material toughness greater than the first material toughness. The deformable layer is also configured to couple the sensing unit to the ductile layer and partially transfer strain resulting from stress applied to the sensing unit to the ductile layer. The layered structure further comprises a sensor interface layer (sensor bonding layer, sensor communication layer) positioned on the second surface of the sensing unit. The microprobe also comprises at least one encapsulant (encapsulant), which is configured to at least partially encapsulate the layered structure and isolate the layered structure from an ambient environment. [Brief description of the drawings]

[0036] Several embodiments of the present disclosure are described herein, by way of example only, with reference to the accompanying drawings, in which: FIG. 1 is a schematic diagram of a method for manufacturing a semiconductor device according to the present invention; FIG. 2 is a schematic diagram of a semiconductor device according to the present invention; [Figure 1A] FIG. 2 is a top view of a sensing system including multiple layered microprobes according to an exemplary embodiment of the present disclosure. [Figure 1B] FIG. 1 is a perspective view of a patch attached to the skin including a sensing system having a layered microprobe according to an exemplary embodiment of the present disclosure. [Diagram 2] 1 is a cross-sectional view of a microprobe including a layered structure according to an exemplary embodiment of the present disclosure. [Diagram 3] FIG. 2 is a top view taken with a scanning electron microscope showing the shaft and tip of a sensing unit according to an exemplary embodiment of the present disclosure. [Figure 4] FIG. 2 is a top view of the shaft and tip of a microprobe according to a first exemplary embodiment of the present disclosure. [Diagram 5] FIG. 13 is a top view of the shaft and tip of a microprobe according to a second exemplary embodiment of the present disclosure. [Figure 6] FIG. 13 is a top view of the shaft and tip of a microprobe according to a third exemplary embodiment of the present disclosure. [Figure 7] 1A-1C are perspective views of a number of lamellar microprobes having various shapes according to exemplary embodiments of the present disclosure; [Figure 8] 1 is a cross-sectional view showing a tip of a sensing unit and a tip of a ductile layer according to a first exemplary embodiment of the present disclosure. [Figure 9] FIG. 11 is a cross-sectional view showing a tip of a sensing unit and a tip of a ductile layer according to a second exemplary embodiment of the present disclosure. [Figure 10] FIG. 13 is a cross-sectional view showing a tip of a sensing unit and a tip of a ductile layer according to a third exemplary embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view showing a tip of a sensing unit and a tip of a ductile layer according to a fourth exemplary embodiment of the present disclosure. [Figure 12] FIG. 2 is a cross-sectional view of a sensing unit and a ductile layer according to a first exemplary embodiment of the present disclosure. [Figure 13] FIG. 11 is a cross-sectional view of a sensing unit and a ductile layer according to a second exemplary embodiment of the present disclosure. [Figure 14] FIG. 13 is a cross-sectional view of a sensing unit and a ductile layer according to a third exemplary embodiment of the present invention. [Figure 15] 1 is a side cross-sectional view of a microprobe according to an exemplary embodiment of the present disclosure; [Figure 16] 16 is a cross-sectional front view of the microprobe of FIG. 15 according to an exemplary embodiment of the present disclosure. [Figure 17] 1 is a cross-sectional view of a portion of the shaft and tip of a microprobe according to a first exemplary embodiment of the present disclosure. [Figure 18] 13 is a cross-sectional view of a portion of the shaft and tip of a microprobe according to a second exemplary embodiment of the present disclosure. [Figure 19] 13 is a cross-sectional view of a portion of the shaft and tip of a microprobe according to a third exemplary embodiment of the present disclosure. [Figure 20] FIG. 13 is a cross-sectional view of a portion of the shaft and tip of a microprobe according to a fourth exemplary embodiment of the present disclosure. [Figure 21] FIG. 13 is a cross-sectional view of a portion of the shaft and tip of a microprobe according to a fifth exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its application or use in any way. Throughout, range descriptions are used as shorthand for describing all values ​​within the range. Any value within the range can be selected as the end of the range. Furthermore, all documents cited herein are incorporated herein by reference in their entirety. In the event of a discrepancy in definition between this disclosure and the cited documents, this disclosure shall prevail.

[0038] The description of illustrative embodiments according to the principles of the invention is intended to be read in connection with the accompanying drawings and should be considered as part of the entire written description. In describing the embodiments of the invention disclosed herein, references to directions or orientations are intended merely for convenience of explanation and are in no way intended to limit the scope of the invention.

[0039] Relative terms such as "lower," "upper," "horizontal," "vertical," "top," "down," "upper," "lower," "left," "right," "top," "bottom," and derivatives thereof (e.g., "horizontal," "downward," "upward," etc.) should be construed to refer to the orientation shown in the description or drawings being discussed. These relative terms are for convenience of description and do not require that the device be constructed or operated in a particular orientation unless expressly indicated.

[0040] As used herein, the term "proximal" refers to a direction toward a user of a device or system, and the term "distal" refers to a direction away from the user.

[0041] The terms "attach," "affix," "connect," "couple," "interconnect," "mount," and similar terms refer to a relationship in which structures are fixed or attached to one another directly or indirectly through intervening structures, and, unless otherwise specified, refer to both movable and fixed attachments or relationships.

[0042] As used in the specification and claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0043] Spatial or directional terms such as "left," "right," "inside," "outside," "up," "down," etc. should not be considered limiting, and the present invention may contemplate various alternative orientations.

[0044] All numbers used in the specification and claims should be understood in any instance as being modified by the term "about," which refers to a range of plus or minus ten percent of the stated value.

[0045] Unless otherwise stated, all ranges or ratios disclosed herein should be understood to encompass any sub-ranges or ratios contained therein. For example, a range stated as "1 to 10," or a ratio stated as "1 to 10," should be considered to include all sub-ranges between (and including) a minimum value of 1 and a maximum value of 10, i.e., all sub-ranges or ratios beginning with a minimum value of 1 or greater and ending with a maximum value of 10 or less, including, but not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0046] The terms "first," "second," and the like are not intended to refer to a particular hierarchy or order, but instead refer to different conditions, characteristics, or elements.

[0047] All documents referenced herein are incorporated by reference in their entirety.

[0048] The term "at least" means "greater than or equal to." The term "less than or equal to" means "less than or equal to."

[0049] The term "including" is synonymous with "comprises."

[0050] As used herein, the term "microprobe" is interchangeable with the terms "microneedle" and "neural probe."

[0051] As used herein, the term "working electrode" is a deposited electrode, typically of a metal such as, for example, gold, silver, tin, zinc, copper, cadmium, chromium, nickel, platinum, palladium, rhodium, tantalum, titanium, and titanium nitride, on which an oxidation-reduction reaction in an electrochemical sensor may occur and which is connected to a power source.

[0052] As used herein, the term "material toughness" is defined as the energy per unit volume that can be absorbed before fracture.

[0053] As used herein, the term "zero debris" process is defined as a process that results in minimal, near zero, or zero debris. The design of the microprobe is to support zero debris processes, for example, by using an encapsulant or by mechanically protecting the tip of a brittle material and / or by providing a layered structure with a compliant material that can reduce the forces and torques on the brittle material.

[0054] As used herein, the term "tip" is defined as the sharp, narrow distal portion of a unit, which may be a microprobe, a sensing unit, a layered structure, or a ductile layer.

[0055] As used herein, the term "distal end" is defined as the most distal point or line of a unit. For example, the distal end of the tip of a microprobe is the portion of the microprobe that first contacts the skin.

[0056] As used herein, the term "shaft" is defined as the part of a unit that connects the tip to the base of the unit. In some embodiments, the tip and shaft may be distinguished by a change in shape. In some cases, the tip and shaft may merge geometrically such that there is no strict boundary separating them.

[0057] For biological and other applications, it is often necessary to use microsensing systems, such as sensors fabricated or attached to microneedles, microprobes, or neural probes. There are advantages to designing a microchip-based sensor system that includes a sensor and a structure to which the sensor is attached that can be fabricated by standard semiconductor manufacturing processes. In some applications, it is beneficial to place the sensor element as close as possible to the medium to be detected. In the case of a microchip-based sensor system, the sensing element may be placed near the tip of the microprobe, which allows the sensing element to be inserted and placed in tissue.

[0058] During use, manufacture, and / or operation, forces or torques may be applied or generated to the microchip-based sensor system and the microneedle. For example, in a microchip-based sensor system, such as an exemplary sensing system 10 with a microprobe 100 as shown in FIG. 1B, the microprobe 10 is inserted into the skin, for example, through a patch 20 attached to the skin, penetrating the epidermis layer. During the time that the patch is placed and the microprobe is inserted through a portion of the epidermis and / or dermis, or during the time that the patch is worn, and when the patch is removed from the skin, forces and torques (as shown by the arrows in FIG. 1B) are applied to the microprobe, for example, due to limb movement and / or muscle movement relative to the patch.

[0059] In general, the thinner the microprobe and the smaller its dimensions, the less pain felt during microneedle insertion. This reduction in pain is due to the lower insertion force required for the microprobe to penetrate the skin and the overall fewer nerve endings affected by such insertion. However, the mechanical size and shape requirements of the microprobe structure may vary depending on the application and often include conflicting design requirements.

[0060] In one example, to minimize insertion forces, the microprobes must have sharply pointed tips, however, microprobes are often made from brittle materials, such as silicon, in which case a sharply pointed tip may not be able to withstand the required insertion forces.

[0061] In another example, it is beneficial to place the sensor element close to the microprobe tip to improve sensing, and this placement dictates the shape and minimum size of the microprobe tip, which may conflict with the desired shape and size requirements for minimizing pain upon microprobe insertion.

[0062] Additionally, material properties are an important contributor to microprobe design. Specifically, most microchip-based sensor systems are formed from brittle materials, so the size and shape of the microprobe must be large to form a mechanically reliable structure. The mechanical reliability of the microprobe is a key design concern. Specifically, the design of the microprobe must ensure that no part of it breaks off, leading to potential damage during operation, insertion, utilization, and / or removal, as fragments or traces of the microprobe may be toxic or otherwise harmful.

[0063] The present disclosure relates to a novel and reliable sensing system including a layered microprobe with a mechanically robust microprobe sensor that can be manufactured using standard semiconductor manufacturing processes. The described sensing system is configured to withstand forces and torques that may be applied or generated during use and operation while minimizing pain during insertion. Furthermore, the sensing system ensures that the insertion, application, and removal of the microprobe is a "zero debris" process.

[0064] As noted above, Figure 1A illustrates a sensing system 10. As shown in Figure 1A, the sensing system 10 includes a planar array 150 having a base 155 and a plurality of lamellar microprobes 100. The sensing system 10 also includes electrical components including connectors 160 and wiring 165. However, in other embodiments, the sensing system 10 has more or less than six lamellar microprobes. In other embodiments, the sensing system 10 has one lamellar microprobe 100.

[0065] In some embodiments, the sensing system 10 may be incorporated into a patch that is worn on the skin for a period of time. FIG. 1B illustrates an exemplary sensor patch 20, which includes a sensing system 10 having at least one layered microprobe 100 inserted into a user's skin 30. In some embodiments, the sensor patch 20 includes a shell or cover that houses the insertion system, power unit, and electronics. FIG. 1B also illustrates forces F1, F2 and torques T1, T2 that may be applied to the patch 20 and microprobe 100 during insertion. Specifically, force F1 and torque T1 act on the patch, for example, during insertion and attachment, while force F2 and torque T2 are reaction forces that act on the microprobe 100 in the skin by F1 and T1.

[0066] 2 shows a microprobe 100 having a layered structure 101, which includes a sensing unit 102, a ductile layer 104, a deformable layer 106, and a sensor interface layer 108. The microprobe 100 also comprises at least one encapsulant 110, which at least partially encapsulates the layered structure 101 of the microprobe 100, as described in more detail below.

[0067] According to some aspects of the disclosure, the sensing unit 102 includes at least one sensor 112. For example, in some embodiments, the sensor 112 is a field effect transistor (FET) based sensor and has a working electrode. In some embodiments, the sensor 112 is a silicon-based FET sensor. In other embodiments, the sensor 112 is any of the following types of electrochemical biosensor, temperature sensor, photosensitive sensor, acoustic sensor, impedance sensor, electromagnetic sensor, magnetic sensor, or radiation sensor.

[0068] 3, in some embodiments, the sensing unit 102 is configured for insertion into the skin of a subject. Specifically, the sensing unit 102, in some embodiments, comprises a base 113 and an elongated shaft 114 that extends to a distal tip 116. The distal tip 116 can have a variety of configurations, as described in further detail below.

[0069] In some embodiments, the thickness of the sensing unit 102 is between 0.01 mm and 0.3 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.05 mm and 0.3 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.1 mm and 0.3 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.15 mm and 0.3 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.1 mm and 0.3 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.25 mm and 0.3 mm.

[0070] In some embodiments, the thickness of the sensing unit 102 is between 0.01 mm and 0.25 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.01 mm and 0.2 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.01 mm and 0.15 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.01 mm and 0.1 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.01 mm and 0.05 mm.

[0071] In some embodiments, the thickness of the sensing unit 102 is between 0.05 mm and 0.25 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.1 mm and 0.15 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.1 mm and 0.25 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.15 mm and 0.2 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.05 mm and 0.25 mm. In other embodiments, the thickness of the sensing unit 102 is between 0.05 mm and 0.1 mm.

[0072] Conventionally, semiconductor-based sensing units include brittle materials. For example, in some embodiments, the brittle material may be any semiconductor material such as silicon (Si), germanium (Ge), and tin (Sn), which are group IV elements (group 14 elements) of the periodic table, and selenium (Se) and tellurium (Te), which are group VI elements (group 16 elements), or a compound semiconductor composed of two or more elements (e.g., gallium arsenide (GaAs)), or a ternary compound, mercury indium telluride (HgIn2Te4), or a semiconductor oxide (silicon oxide), a metal oxide (aluminum oxide), and a semiconductor metal oxide (zinc oxide). These sensing units may have a sharp tip for insertion into the skin. However, the silicon (Si) material of such sensing units is brittle, and a small force or torque may cause the silicon (Si) to break, which may result in breakage and release of silicon (Si) fragments. Silicon (Si) sharp tips often cannot sustain the axial or other external forces required for insertion into the skin without fracturing or breaking, potentially leaving behind microscopic debris or fragments. Additionally, silicon-based tips are very difficult to manufacture and sharpen to a sharp tip.

[0073] To prevent the brittle silicon (Si) from breaking and / or fracturing, in some embodiments, the silicon (Si)-based sensing unit 102 is mounted on a ductile layer 104. In some embodiments, the ductile layer 104 comprises a material capable of absorbing most of the external forces applied to the microprobe 100 during operation and insertion. In some embodiments, the ductile layer 104 comprises, for example, any metal, metal alloy, or composite material. In some embodiments, the ductile layer 104 comprises stainless steel. The material toughness of the ductile layer material, in some embodiments, is significantly greater than that of the silicon-based sensing unit, such that the combined structure of the sensing unit 102 and the ductile layer 104 can withstand higher external forces / torques than the individual materials alone. For example, in some embodiments, the material toughness of the ductile layer material is an order of magnitude greater than that of the sensing unit material. Thus, the ductile layer 104 serves to support the brittle sensing unit 102, thereby allowing the microstructure of the sensing unit made of such brittle material to function. Furthermore, the toughness of the combination of the sensing unit 102 and the ductile layer 104 allows for the design of thinner microprobes compared to microprobes that use the brittle material of the sensing unit 102 alone (eg, silicon (Si)).

[0074] As noted above, in some embodiments, the ductile layer 104 is configured to absorb forces and torques applied to the microprobe 100 during its use and / or operation. Thus, the ductile layer 104 is shaped to reduce or dissipate forces and torques applied to the microprobe 100 during its use and / or operation. Specifically, as shown in FIG. 4, the ductile layer 104 substantially follows the shape of the sensing unit 102 in several planes and is shaped to provide support to the sensing unit 102 while providing protection in other ways.

[0075] As shown in FIGS. 4-7, in an exemplary embodiment, the ductile layer 104 comprises an elongated shaft 120 extending from a base 121 to a tip 122 of the ductile layer 104, the shaft 120 being coincident with the sensing unit 102. As shown in FIG. 7, the shafts 114, 120 of the sensing unit 102 and the ductile layer 104 together form a shaft 124 of the layered structure 101. In some embodiments, the shaft 114 of the sensing unit is connected to the shaft 120 of the ductile layer 104 along its entire length. This provides support to the sensing unit 102 along the length of the shaft 114 of the sensing unit 102 such that the sensing unit 102 is mechanically constrained, minimizing the forces acting on the shaft 120 of the sensing unit. Furthermore, in some embodiments, the ductile layer 104 is aligned with the stacking direction D of the layered structure 101. L (see FIG. 2 ) has an increased area compared to the sensing unit 102. For example, the sensing unit 102 has an increased area compared to the stacking direction D of the layered structure 101. L When viewed from the first outer periphery (periphery) P S The ductile layer 104 has a stacking direction D L When viewed from the second outer periphery (periphery) P D The first outer periphery P S is completely in the second outer periphery P D 4-6 show various shapes and sizes of the ductile layer 104 when attached to the sensing unit 102.

[0076] In the first exemplary embodiment shown in FIG. 4, the width of the ductile layer 104 is L 1, the width of the ductile layer 104 is substantially the same as the width of the sensing unit 102, except that the shaft 120 and / or tip 122 of the ductile layer 104 is longer than the shaft and / or tip of the sensing unit 102, such that the ductile layer 104 extends beyond the distal end 118 of the sensing unit 102.

[0077] In the second exemplary embodiment shown in FIG. 5, the width of the ductile layer 104 is LAs seen in the figure, the ductile layer 104 has a width that is greater at the proximal base of the ductile layer shaft 120 than the width of the sensing unit shaft 114.

[0078] In the third exemplary embodiment shown in FIG. 6, the width of the ductile layer 104 is L When viewed from the outside, the ductile layer 104 is substantially uniform in some areas and more distally tapers toward its distal end, although the width of the ductile layer 104 is greater than the width of the sensing unit 102 along its entire length.

[0079] In some embodiments, the shape of the ductile layer 104 may be tailored to protect the tip of the sensing unit 102 from foreseeable and / or unforeseeable forces that may cause fracturing or breaking, based on the application. Specifically, as described above, in some embodiments, the distal portion of the ductile layer 104 extends beyond the distal end 118 of the tip 116 of the sensing unit 102. In these embodiments, because the ductile layer 104 protrudes distally beyond the distal end 118 of the sensing unit 102, the ductile layer 104 is inserted into the skin prior to the sensing unit 102, thereby protecting the sensing unit 102 from axial and lateral insertion forces and minimizing the risk of breaking the tip 116 of the sensing unit. FIGS. 7-11 show various exemplary designs in which the ductile layer 104 is shaped to protect the tip 116 and distal end 118 of the sensing unit, as described in further detail below.

[0080] In some embodiments, as shown, for example, in FIGS. 8-9, the tips 116, 122 of the sensing unit 102 and the ductile layer 104, respectively, are both sharply formed for insertion into the skin of a subject. In such embodiments, the tip 122 of the ductile layer is configured to protrude or extend beyond the distal end 118 of the sensing unit 102. Thus, the ductile layer 104, and not the sensing unit 102, receives the majority of the insertion force first. Furthermore, since the ductile layer 104 is inserted into the skin before the sensing unit 102, the ductile layer 104 forms the first hole or opening in the skin. As a result, the tip 116 of the sensing unit 102 is inserted into the previously formed hole, thereby minimizing the axial force applied to the tip 116 of the sensing unit 102, thereby reducing the risk of fracturing, breaking, or shattering the relatively fragile sensing unit 102. FIG. 7 shows a perspective view of a layered shaft 124a having a similar tip 116, 222 configuration.

[0081] In another embodiment, as shown, for example, in Figures 10-11, the tip 116 of the sensing unit 102 is protected in two planes from potential insertion / manipulation forces by the ductile layer 104. First, similar to the ductile layer 104 of Figures 8 and 10, the ductile layer 104 includes a sharpened tip 122 that extends beyond the distal end 118 of the sensing unit 102. Second, the ductile layer 104 is oriented in the stacking direction D. L 1, the ductile layer 104 covers or surrounds the distal end 118 or surface of the tip 116 of the sensing unit 102. Thus, the tip 116 of the sensing unit 102 is almost completely protected from axial insertion forces because the ductile layer 104 alone creates and enlarges the opening in the subject's skin. Figure 7 shows a perspective view of a layered shaft 124b with a similar tip 116, 222 configuration that completely protects the tip 116 from axial insertion forces.

[0082] In some embodiments, the sensing unit 102 is also protected by the ductile layer 104 on the sides of the sensing unit 102, as shown in Figures 12-14. Specifically, the ductile layer 104 covers at least a portion of the sides of the shaft 114 and tip 116 of the sensing unit to minimize lateral or sideways forces applied during operation and use. In some embodiments, the ductile layer 104 includes a recess 134 in a surface 136 adjacent the sensing unit 102, such that the sensing unit 102 is received within and at least partially surrounded by the recess 134. As shown in Figure 12, in some embodiments, the recess 134 has a depth D. The depth D is equal to a dimension W between a first surface 126 of the sensing unit 102 adjacent the ductile layer 104 and a second surface 128 of the sensing unit 102 opposite the first surface 126. As shown in FIG. 13, in another embodiment, the recess 134 has a depth D that is smaller than the dimension W of the sensing unit 102. As seen in FIG. 13, in this embodiment, the ductile layer 104 covers only a portion of the side of the sensing unit 102. As shown in FIG. 14, in another embodiment, the recess 134 has a depth D that is larger than the dimension W of the sensing unit 102. As seen in FIG. 14, in this embodiment, the ductile layer 104 covers and protrudes beyond the side of the sensing unit 102. FIG. 7 shows a perspective view of a layered shaft 124c with a tip 116, 222 configuration that protects the tip 116 on both sides. It is noted that while FIG. 7 shows multiple layered microprobes 100 with different microprobe designs, in other embodiments, all the microprobes 100 may have the same design.

[0083] In some embodiments, the length of the ductile layer, i.e., the dimension from base 121 to tip 122 of ductile layer 104, is between 0.8 mm and 2.0 mm. In other embodiments, the length of ductile layer 104 is between 0.8 mm and 1.8 mm. In other embodiments, the length of ductile layer 104 is between 0.8 mm and 1.6 mm. In other embodiments, the length of ductile layer 104 is between 0.8 mm and 1.4 mm. In other embodiments, the length of ductile layer 104 is between 0.8 mm and 1.2 mm. In other embodiments, the length of ductile layer 104 is between 0.8 mm and 1.0 mm.

[0084] In some embodiments, the length of the ductile layer 104 is between 1.0 mm and 2.0 mm. In other embodiments, the length of the ductile layer 104 is between 1.2 mm and 2.0 mm. In other embodiments, the length of the ductile layer 104 is between 1.4 mm and 2.0 mm. In other embodiments, the length of the ductile layer 104 is between 1.6 mm and 2.0 mm. In other embodiments, the length of the ductile layer 104 is between 1.8 mm and 2.0 mm.

[0085] In some embodiments, the length of the ductile layer 104 is between 1.2 mm and 1.6 mm. In other embodiments, the length of the ductile layer 104 is between 1.0 mm and 1.4 mm. In other embodiments, the length of the ductile layer 104 is between 1.4 mm and 1.6 mm. In other embodiments, the length of the ductile layer 104 is between 1.6 mm and 1.8 mm. In other embodiments, the length of the ductile layer 104 is between 1.2 mm and 1.8 mm.

[0086] In some embodiments, the thickness of the ductile layer 104 is between 0.01 mm and 0.3 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.05 mm and 0.3 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.1 mm and 0.3 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.15 mm and 0.3 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.1 mm and 0.3 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.25 mm and 0.3 mm.

[0087] In some embodiments, the thickness of the ductile layer 104 is between 0.01 mm and 0.25 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.01 mm and 0.2 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.01 mm and 0.15 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.01 mm and 0.1 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.01 mm and 0.05 mm.

[0088] In some embodiments, the thickness of the ductile layer 104 is between 0.05 mm and 0.25 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.1 mm and 0.15 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.1 mm and 0.25 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.15 mm and 0.2 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.15 mm and 0.25 mm. In other embodiments, the thickness of the ductile layer 104 is between 0.05 mm and 0.1 mm.

[0089] In the above exemplary configurations, the width and thickness of the silicon (Si) of the sensing unit 102 can be reduced in response to a reduction in applied external forces and torques. Thus, in some embodiments, the combined thickness and / or width of the sensing unit 102 and ductile layer 104 may be less than the thickness and / or width required for the sensing unit alone to withstand the manipulation and insertion forces. Such a reduction in dimensions is beneficial in that less force is required to insert into the skin or other tissue, reducing pain.

[0090] In some embodiments, the layered structure of the microprobe 100 comprises a deformable layer 106 disposed on the first surface 126 of the sensing unit 102 between the sensing unit 102 and the ductile layer 104. In some embodiments, the deformable layer 106 is also disposed on the side surface 142 of the sensing unit 102. As used herein, the deformable layer 106 is defined as a layer of material having sufficient material properties (e.g., elasticity) to perform at least one desired function under normal operating procedures of the sensing system 10 (e.g., sufficient material properties to deform under stresses applied to the sensing system 10). In some embodiments, the deformable layer 106 electrically insulates the silicon (Si) of the sensing unit 102 from the material of the ductile layer 104. In some embodiments, the ductile layer 104 protects the sensing unit 102 from electrical noise and / or serves as a ground for at least one sensor 112. In other embodiments where it is preferred that the sensing unit 102 and the ductile layer 104 are in contact with one another, such as for precise positioning of the sensing unit 102 and the ductile layer 104 relative to one another, where there is less process control over the thickness of the deformable layer 106, depressions or channels may be incorporated into the surfaces of the silicon (Si) of the sensing unit 102 and the ductile layer 104. In this case, the deformable layer 106 may be disposed within the channels while other portions of the surfaces of the sensing unit 102 and the ductile layer 104 are in physical contact.

[0091] In some embodiments, the deformable layer 106 comprises a polymeric material, such as, for example, polyurethane, silicone, polyacrylate, methacrylate, polymethylmethacrylate, polyamide, SU-8, parylene, epoxy, polydimethylsiloxane, etc. In some embodiments, the deformable layer 106 is reinforced with a metal oxide, such as aluminum oxide, silicon oxide, or silicon oxynitride. In some embodiments, the deformable layer 106 comprises a viscoelastic material, such as an amorphous polymer, a semi-crystalline polymer, or a biopolymer.

[0092] In some embodiments, the deformable layer 106 is an adhesive. In some embodiments, the deformable layer 106 includes a first adhesive, a deformable material, and a second adhesive. Specifically, in some embodiments, the deformable layer 106 includes a deformable material disposed between the first adhesive and the second adhesive.

[0093] In some embodiments, the deformable layer 106 has a thickness between 1 micron and 100 microns. In other embodiments, the deformable layer 106 has a thickness between 5 microns and 100 microns. In other embodiments, the deformable layer 106 has a thickness between 10 microns and 100 microns. In other embodiments, the deformable layer 106 has a thickness between 50 microns and 100 microns. In other embodiments, the deformable layer 106 has a thickness between 90 microns and 100 microns. In other embodiments, the deformable layer 106 has a thickness between 95 microns and 100 microns.

[0094] In some embodiments, the thickness of the deformable layer 106 is between 1 micron and 100 microns. In other embodiments, the thickness of the deformable layer 106 is between 1 micron and 95 microns. In other embodiments, the thickness of the deformable layer 106 is between 1 micron and 75 microns. In other embodiments, the thickness of the deformable layer 106 is between 1 micron and 50 microns. In other embodiments, the thickness of the deformable layer 106 is between 1 micron and 10 microns. In other embodiments, the thickness of the deformable layer 106 is between 1 micron and 5 microns.

[0095] In some embodiments, the deformable layer 106 has a thickness between 5 microns and 10 microns. In other embodiments, the deformable layer 106 has a thickness between 10 microns and 50 microns. In other embodiments, the deformable layer 106 has a thickness between 50 microns and 75 microns. In other embodiments, the deformable layer 106 has a thickness between 5 microns and 50 microns. In other embodiments, the deformable layer 106 has a thickness between 10 microns and 95 microns. In other embodiments, the deformable layer 106 has a thickness between 25 microns and 50 microns.

[0096] In some embodiments, the thickness of the deformable layer 106 is greater than the greater of the surface roughness Ra of the sensing unit 102 and the surface roughness Ra of the ductile layer 104, thereby preventing the sensing unit 102 and the ductile layer 104 from contacting each other.

[0097] In some embodiments, the layered structure of the microprobe 100 further comprises a sensor interface layer 108. In some embodiments, the sensor interface layer 108 provides a specific function to the sensor 112, such as analyte specificity. Specifically, the sensor interface layer 108 may include enzyme antibodies, small molecules, and hydrogels. In some embodiments, the sensor interface layer also provides a barrier between the sensor 112 and the surrounding environment. In some embodiments, the sensor interface layer 108 is biodegradable and changes properties over time or over its application life. As shown in FIG. 2, the sensor interface layer 108 is disposed on the second side 128 of the sensing unit 102, opposite the first side 126. In some embodiments, the sensor interface layer 108 is in contact with the material of the sensing unit 102 (e.g., silicon (Si)) and the components of the sensor 112. In one embodiment, the sensor interface layer 108 is applied (applied) to the sensing unit 102 as part of the sensor manufacturing process using a semiconductor coating process such as, for example, spin coating, spray coating, brushing, dipping, chemical vapor deposition, or physical vapor deposition.

[0098] In some embodiments, the sensor interface layer 108 comprises, for example, polyamide, polyurethane, or other materials. In some embodiments, the sensor interface layer 108 comprises a material having high tensile strength. In other embodiments, the sensor interface layer 108 comprises a flexible material.

[0099] In some embodiments, the material of the sensor interface layer 108 may allow for patterning such that planar structures including gaps, holes, openings, vias, traces, crevices, or channels may be formed. In some embodiments, the openings or gaps are circular, oval, rectangular, or other shapes. In some embodiments, the openings are over a portion of the sensor 112. In some embodiments, the openings are over an electrical, electrochemical, or photoelectric component of the sensor 112, such as an electrode, conductive trace, or nanowire. In some embodiments, the openings are over a portion of a field effect transistor sensor.

[0100] In some embodiments, the sensor interface layer 108 has one or more of the following characteristics: chemically inert, biocompatible, biodegradable, antifouling, hydrophobic, hydrophilic, or a low coefficient of friction.

[0101] In some embodiments, the sensor interface layer 108 has a thickness between 10 nanometers and 200 microns. In other embodiments, the sensor interface layer 108 has a thickness between 100 nanometers and 200 microns. In other embodiments, the sensor interface layer 108 has a thickness between 1 micron and 200 microns. In other embodiments, the sensor interface layer 108 has a thickness between 10 microns and 200 microns. In other embodiments, the sensor interface layer 108 has a thickness between 50 microns and 200 microns. In other embodiments, the sensor interface layer 108 has a thickness between 100 microns and 200 microns.

[0102] In some embodiments, the sensor interface layer 108 has a thickness between 10 nanometers and 150 microns. In other embodiments, the sensor interface layer 108 has a thickness between 10 nanometers and 100 microns. In other embodiments, the sensor interface layer 108 has a thickness between 10 nanometers and 50 microns. In other embodiments, the sensor interface layer 108 has a thickness between 10 nanometers and 10 microns. In other embodiments, the sensor interface layer 108 has a thickness between 10 nanometers and 1 micron. In other embodiments, the sensor interface layer 108 has a thickness between 10 nanometers and 100 nanometers.

[0103] In some embodiments, the sensor interface layer 108 has a thickness between 100 nanometers and 1 micron. In other embodiments, the sensor interface layer 108 has a thickness between 1 micron and 10 microns. In other embodiments, the sensor interface layer 108 has a thickness between 10 microns and 50 microns. In other embodiments, the sensor interface layer 108 has a thickness between 50 microns and 100 microns.

[0104] In some embodiments, as shown in Figures 15-16, the sensor interface layer 108 covers only the sensor 112 of the sensing unit 102. L When viewed from the side, the outer periphery (edge) of the sensor interface layer 108 is substantially the same as the outer periphery (edge) of the sensor 112, such that other parts of the sensing unit 102 are not covered by the sensor interface layer 108. In some embodiments, the sensor interface layer 108 covers the sensor 112 of the sensing unit 102 and a part of the sensing unit 102. Specifically, in the stacking direction D L When viewed from the outside, the perimeter of the sensor interface layer 108 is smaller than the perimeter of the sensor.

[0105] 2, the microprobe 100 comprises at least one encapsulant 110 that at least partially encapsulates the layered structure of the microprobe 100. In some embodiments, the encapsulant 110 is configured to contain any debris that may be formed by (e.g., originating from) components of the layered structure encapsulated therein. Also, in some embodiments, the encapsulant 110 is configured to ensure that any debris formed by the layered structure can be removed by the sensing system 10 during removal from the subject's skin.

[0106] In some embodiments, the sealant 110 is designed to isolate (isolate) the components of the microprobe from the surrounding environment to extend their usable life. In some embodiments, the sealant 110 provides electrical insulation (electronic isolation). In other embodiments, the sealant 110 provides mechanical or spatial isolation but not electrical isolation. In some embodiments, the sealant 110 provides a uniform coefficient of friction on all surfaces of the microprobe 100. A uniform coefficient of friction on all surfaces of the microprobe may reduce asymmetric lateral forces that may cause buckling or twisting of the microprobe shaft 124. In further embodiments, the sealant 110 provides mechanical isolation but allows the passage or diffusion of liquids, gases, chemicals, and / or biochemicals.

[0107] In some embodiments, the encapsulant 110 partially encapsulates the layered structure 101. For example, in some embodiments, the encapsulant 110 covers 10%-99% of the surface of the layered structure 101. In other embodiments, the encapsulant 110 covers 20%-99% of the layered structure 101. In other embodiments, the encapsulant 110 covers 25%-99% of the layered structure 101. In other embodiments, the encapsulant 110 covers 50%-99% of the layered structure 101. In other embodiments, the encapsulant 110 covers 75%-99% of the layered structure 101. In other embodiments, the encapsulant 110 covers 90%-99% of the layered structure 101.

[0108] In some embodiments, the encapsulant 110 covers between 10% and 90% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 10% and 75% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 10% and 50% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 10% and 25% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 10% and 20% of the layered structure 101.

[0109] In some embodiments, the encapsulant 110 covers between 20% and 90% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 25% and 75% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 50% and 75% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 20% and 5% of the layered structure 101. In other embodiments, the encapsulant 110 covers between 75% and 90% of the layered structure 101.

[0110] In some embodiments, the encapsulant 110 encapsulates portions of some sides of the layered structure 101. In other embodiments, the encapsulant 110 encapsulates a portion of the top surface of the layered structure 101. In other embodiments, the encapsulant 110 encapsulates the top surface and portions of the sides of the layered structure 101. In further embodiments, the encapsulant 110 encapsulates the entire layered structure 101 except for a portion of the tip 122 of the layered structure 101, as described in more detail below.

[0111] In some embodiments, the encapsulant 110 includes a hydrogel that increases in volume when exposed to a liquid environment. For example, in some embodiments, the encapsulant 110 includes a hydrogel in the fixation area around the sensor 112. In some embodiments, the encapsulant material does not include a hydrogel. The change in volume has many advantages, such as allowing diffusion of analytes and biomolecules from the tissue or liquid environment to the sensor, volumetric tissue displacement, facilitating fixation of the microprobe 100 in the tissue, clogging prevention, anti-inflammatory and anti-proliferative properties, the latter preventing clogging of the sensor due to tissue growth. In some embodiments, the volume of the hydrogel can increase by 1% to 1000%. In other embodiments, the volume of the hydrogel can increase by 10% to 1000%. In other embodiments, the volume of the hydrogel can increase by 100% to 1000%. In other embodiments, the volume of the hydrogel can increase by 500% to 1000%.

[0112] In some embodiments, the volume of the hydrogel may increase by 1% to 500%. In other embodiments, the volume of the hydrogel may increase by 1% to 100%. In other embodiments, the volume of the hydrogel may increase by 1% to 10%. In other embodiments, the volume of the hydrogel may increase by 1% to 5%.

[0113] In some embodiments, the volume of the hydrogel can increase by 10% to 100%. In other embodiments, the volume of the hydrogel can increase by 100% to 500%. In other embodiments, the volume of the hydrogel can increase by 5% to 10%. In other embodiments, the volume of the hydrogel can increase by 10% to 500%.

[0114] In some embodiments, the thickness of the encapsulant 110 is between 100 nanometers and 200 microns. In other embodiments, the thickness of the encapsulant 110 is between 1 micron and 200 microns. In other embodiments, the thickness of the encapsulant 110 is between 10 microns and 200 microns. In other embodiments, the thickness of the encapsulant 110 is between 50 microns and 200 microns. In other embodiments, the thickness of the encapsulant 110 is between 100 microns and 200 microns.

[0115] In some embodiments, the thickness of the encapsulant 110 is between 100 nanometers and 100 microns. In other embodiments, the thickness of the encapsulant 110 is between 100 nanometers and 50 microns. In other embodiments, the thickness of the encapsulant 110 is between 100 nanometers and 10 microns. In other embodiments, the thickness of the encapsulant 110 is between 100 nanometers and 1 micron.

[0116] In some embodiments, the thickness of the encapsulant 110 is between 1 micron and 100 microns. In other embodiments, the thickness of the encapsulant 110 is between 10 microns and 50 microns. In other embodiments, the thickness of the encapsulant 110 is between 50 microns and 150 microns. In other embodiments, the thickness of the encapsulant 110 is between 1 micron and 10 microns.

[0117] In some embodiments, the encapsulant 110 includes at least one of an oxide, a metal oxide, a native oxide, a polymer, parylene, a primer, polytetrafluoroethylene, or a polyamide. In some embodiments, the encapsulant 110 includes two or more materials.

[0118] The encapsulant 110 may be applied to the layered structure 101 of the microprobe 100 via dipping, chemical vapor deposition, physical vapor deposition, brushing, spray coating, or other methods.

[0119] In some embodiments, the encapsulant 110 may have one or more of the following characteristics: chemical inertness, biocompatible, biodegradable, stain resistant, hydrophobic, hydrophilic, or a low coefficient of friction.

[0120] In some embodiments, the material of the encapsulant 110 may allow for patterning such that planar structures including gaps, holes, openings, vias, traces, crevices, or channels may be formed. In some embodiments, the openings or gaps are circular, oval, rectangular, or other shapes. In some embodiments, there is an opening 140 over a portion of the sensor 112, as shown in FIG. 3. In some embodiments, the opening 140 is located on the shaft of the microprobe 100. In other embodiments, the opening 140 is located on the tip of the microprobe 100.

[0121] In some embodiments, the microprobe 100 is selectively encapsulated. For example, in some embodiments, the bottom and vertical surfaces of the layered structure 101 of the microprobe 100 are encapsulated, but the sensing unit 102 and the sensor interface layer 108 are not encapsulated. In another embodiment, the bottom and vertical surfaces of the layered structure 101 are encapsulated with a first sealing material (first encapsulation material), while the sensing unit 102 and the sensor interface layer 106 are encapsulated with a second sealing material (second encapsulation material).

[0122] In some embodiments, different layers or different components in the layered structure 101 may also be selectively encapsulated. For example, some layers may be encapsulated to prevent debris, to electrically insulate the layers, or to isolate the layers from the environment. In some embodiments, one or both of the sensing unit 102 and the ductile layer 104 are encapsulated with an oxide, a metal oxide, a natural oxide, a polymer, a primer, parylene, polytetrafluoroethylene, or a polyamide.

[0123] The thickness of the encapsulant 110 may also vary around the layered structure 101. For example, in some embodiments, the thickness of the encapsulant 110 is uniform about all sides of the layered structure 101. However, in other embodiments, the thickness of the encapsulant 110 is not uniform about all sides of the layered structure 101. For example, in one embodiment, the thickness of the encapsulant 110 at the tip of the shaft 124 of the layered structure is less than the thickness of the encapsulant 110 at the top and bottom surfaces.

[0124] In some embodiments, the shape and thickness of the sealant 110 along the layered structure 101 may vary from one location to another. In particular, the shape and thickness of the sealant 110 along the shaft 124 and the tip 130 of the layered structure 101 are determined by many factors, including, for example, the dimensions of the tip 130 of the layered structure, the properties of the sealant (encapsulant), and the manner in which the sealant 110 is applied to the layered structure 110. There are three requirements for encapsulation of the tip 130 of the layered structure: the first requirement is that the sealant (encapsulant) does not significantly increase the dimensions of the tip 130 of the layered structure, allowing for painless insertion into the skin; the second requirement is that the sealant adheres firmly to the tip 130 of the layered structure. The third requirement is that the sealant material not generate debris near the tip 130 of the layered structure during operation, insertion, or use (i.e., there is no peeling, cracking, tearing, or breaking of the sealant material).

[0125] As shown in FIG. 17, in some embodiments, the thickness of the sealant 110 decreases along the shaft 124 of the layered structure 101 as it approaches the tip of the layered structure 101. Thus, at the distal end 132 of the tip 130 of the layered structure, the sealant converges to the shape of the ductile layer 104. In another embodiment, the thickness of the sealant 110 is uniform along the shaft 124 of the layered structure 101 and extends beyond the distal end 132 of the tip 130. Specifically, as shown in FIG. 18, the sealant 110 extends beyond and encapsulates the tip 130 of the layered structure 101. In a further embodiment, the thickness of the sealant 110 decreases along the shaft 124 of the layered structure 101 as it approaches the tip 130. However, as shown in Figure 19, the sealant 110 does not extend all the way to the distal end 132 of the tip 130 of the layered structure 101, but rather converges to the tip 130 near the distal end 132. As shown in Figure 20, in another embodiment, the thickness of the sealant 110 is uniform along a portion of the shaft 124 of the layered structure 101 and terminates in a straight contour near the tip 130 of the layered structure.

[0126] As shown in FIG. 21 , in cases where the sealing material includes two or more sealing materials (encapsulants), in some embodiments, a first sealing material (first encapsulant) 110a is provided along a proximal portion of the shaft 124 and / or tip 130 and a second sealing material (second encapsulant) 110b is provided along a distal portion of the shaft 124 and / or tip 130.

[0127] In some embodiments, the distance M between adjacent microprobes 100 (as shown in FIG. 1A) Dis 0.1 mm to 3.0 mm. In another embodiment, the distance between adjacent microprobes 100 is 0.1 mm to 2.5 mm. In another embodiment, the distance between adjacent microprobes 100 is 0.1 mm to 2.0 mm. In another embodiment, the distance between adjacent microprobes 100 is 0.1 mm to 1.5 mm. In another embodiment, the distance between adjacent microprobes 100 is 0.1 mm to 1.0 mm. In another embodiment, the distance between adjacent microprobes 100 is 0.1 mm to 0.5 mm.

[0128] In some embodiments, the distance between adjacent microprobes 100 is between 0.5 mm and 3.0 mm. In other embodiments, the distance between adjacent microprobes 100 is between 1.0 mm and 3.0 mm. In other embodiments, the distance between adjacent microprobes 100 is between 1.5 mm and 3.0 mm. In other embodiments, the distance between adjacent microprobes 100 is between 2.0 mm and 3.0 mm. In other embodiments, the distance between adjacent microprobes 100 is between 2.5 mm and 3.0 mm.

[0129] In some embodiments, the distance between adjacent microprobes 100 is between 0.5 mm and 2.5 mm. In other embodiments, the distance between adjacent microprobes 100 is between 1.0 mm and 2.0 mm. In other embodiments, the distance between adjacent microprobes 100 is between 1.5 mm and 2.5 mm. In other embodiments, the distance between adjacent microprobes 100 is between 0.5 mm and 1.0 mm. In other embodiments, the distance between adjacent microprobes 100 is between 2.0 mm and 2.5 mm.

[0130] As mentioned above, the smaller the sensing system, the less pain felt during insertion and use. Therefore, it is an object of the present invention to minimize the size of the disclosed sensing system 10. Due to the novel structure of the sensing system 10 of the present embodiment, the size of the sensing system 10 is minimized compared to conventional microprobe systems.

[0131] For example, in some embodiments, the length L of the sensing system 10 (shown in FIG. 1A ) L In another embodiment, the length of the sensing system 10 is between 2 mm and 10 mm. In another embodiment, the length of the sensing system 10 is between 2 mm and 8 mm. In another embodiment, the length of the sensing system 10 is between 2 mm and 6 mm. In another embodiment, the length of the sensing system 10 is between 2 mm and 4 mm.

[0132] In some embodiments, the length of the sensing system 10 is between 4 mm and 10 mm. In other embodiments, the length of the sensing system 10 is between 6 mm and 10 mm. In other embodiments, the length of the sensing system 10 is between 8 mm and 10 mm.

[0133] In other embodiments, the length of the sensing system 10 is between 4 mm and 8 mm. In some embodiments, the length of the sensing system 10 is between 4 mm and 6 mm. In other embodiments, the length of the sensing system 10 is between 6 mm and 8 mm.

[0134] In some embodiments, the width W of the sensing system 10 (as shown in FIG. 1A ) L is 0.5 mm to 5 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 4.5 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 4.0 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 3.5 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 3.0 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 2.5 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 2.0 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 1.5 mm. In another embodiment, the width of the sensing system 10 is 0.5 to 1.0 mm.

[0135] In some embodiments, the width of the sensing system 10 is between 1.0 mm and 5.0 mm. In other embodiments, the width of the sensing system 10 is between 1.5 and 5.0 mm. In other embodiments, the width of the sensing system 10 is between 2.0 and 5.0 mm. In other embodiments, the width of the sensing system 10 is between 2.5 and 5.0 mm. In other embodiments, the width of the sensing system 10 is between 3.0 and 5.0 mm. In other embodiments, the width of the sensing system 10 is between 3.5 and 5.0 mm. In other embodiments, the width of the sensing system 10 is between 4.0 and 5.0 mm. In other embodiments, the width of the sensing system 10 is between 4.5 and 5.0 mm.

[0136] In some embodiments, the width of the sensing system 10 is between 1.0 mm and 4.5 mm. In other embodiments, the width of the sensing system 10 is between 1.5 and 4.0 mm. In other embodiments, the width of the sensing system 10 is between 3.5 and 4.0 mm. In other embodiments, the width of the sensing system 10 is between 2.0 and 3.5 mm. In other embodiments, the width of the sensing system 10 is between 4.0 and 4.5 mm.

[0137] In some embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.4 mm. In other embodiments, the thickness of the sensing system 10 is between 0.1 mm and 0.4 mm. In other embodiments, the thickness of the sensing system 10 is between 0.15 mm and 0.4 mm. In other embodiments, the thickness of the sensing system 10 is between 0.2 mm and 0.4 mm. In other embodiments, the thickness of the sensing system 10 is between 0.25 mm and 0.4 mm. In other embodiments, the thickness of the sensing system 10 is between 0.3 mm and 0.4 mm. In other embodiments, the thickness of the sensing system 10 is between 0.35 mm and 0.4 mm.

[0138] In some embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.35 mm. In other embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.3 mm. In other embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.25 mm. In other embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.2 mm. In other embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.15 mm. In other embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.1 mm.

[0139] In some embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.35 mm. In other embodiments, the thickness of the sensing system 10 is between 0.1 mm and 0.15 mm. In other embodiments, the thickness of the sensing system 10 is between 0.15 mm and 0.25 mm. In other embodiments, the thickness of the sensing system 10 is between 0.2 mm and 0.3 mm. In other embodiments, the thickness of the sensing system 10 is between 0.05 mm and 0.35 mm. In other embodiments, the thickness of the sensing system 10 is between 0.3 mm and 0.35 mm. In other embodiments, the thickness of the sensing system 10 is between 0.5 mm and 0.1 mm.

[0140] It is understood that features of the present disclosure may be described in the context of separate embodiments for clarity, or may be provided in a single embodiment. Conversely, various features of the present disclosure may be described in the context of a single embodiment for brevity, or may be provided separately, or in any subcombination, or may be provided in any other embodiment of the present disclosure as appropriate. Certain features described in the context of various embodiments are not to be construed as essential features of such an embodiment, unless the embodiment is infeasible without those elements.

Claims

1. A sensing system comprising at least one microprobe, The microprobe comprises a layered structure and at least one encapsulant; The layered structure is A sensing unit comprising at least one sensor having a working electrode, the sensing unit having a first outer periphery when viewed from a stacking direction of the layered structure, the sensing unit comprising a first material having a first material toughness, and a first surface and a second surface opposite to the first surface; a deformable layer positioned on the first surface of the sensing unit and configured to deform under a stress; a ductile layer positioned on the deformable layer on the opposite side to the sensing unit, the ductile layer having a second perimeter when viewed in a stacking direction of the layered structure, the first perimeter being completely contained within the second perimeter, the ductile layer comprising a second material having a second material toughness greater than the first material toughness; a sensor interface layer positioned on the second surface of the sensing unit; The at least one encapsulant is configured to at least partially encapsulate the layered structure and mechanically isolate the layered structure from an ambient environment.

2. 2. The sensing system of claim 1, wherein the encapsulant is configured to contain debris from at least one of the first material, the second material, a material of the deformable layer, or a material of the sensor interface layer.

3. The sensing system of claim 1 , wherein the encapsulant is at least one of chemically inert, biocompatible, biodegradable, anti-fouling, hydrophobic, or hydrophilic.

4. The sensing system of claim 1 , wherein the encapsulant is configured to electrically insulate the layered structure from the surrounding environment.

5. The sensing system of claim 1 , wherein the encapsulant comprises an opening open to the sensor interface layer.

6. The sensing system of claim 5 , wherein the opening contains a hydrogel configured to increase in volume upon contact with a liquid.

7. The sensing system of claim 1 , wherein the encapsulant completely encapsulates the layered structure.

8. The sensing system of claim 1 , wherein at least a portion of the tip of the sensing unit is unencapsulated.

9. The sensing system of claim 1 , wherein the sensor interface layer is at least one of chemically inert, biocompatible, biodegradable, antifouling, hydrophobic, or hydrophilic.

10. The sensing system of claim 1 , wherein the sensor interface layer has a thickness in the range of 10 nanometers to 200 microns.

11. The sensing system of claim 1 , wherein the deformable layer is an adhesive.

12. The sensing system of claim 1 , wherein the deformable layer has a thickness in the range of 1 micron to 100 microns.

13. The sensing system of claim 1 , wherein the sensing unit is adhered to the ductile layer via a multi-layer structure having a first adhesive, a deformable material, and a second adhesive.

14. The sensing system of claim 1 , wherein a thickness of the deformable layer is greater than a surface roughness of each of the sensing unit and the ductile layer.

15. The sensing system of claim 1 , wherein the deformable layer electrically insulates the sensing unit from the ductile layer.

16. The sensing system of claim 1 , wherein the ductile layer comprises a metal.

17. the ductile layer comprises a recess on a surface adjacent the sensing unit; The sensing system of claim 1 , wherein the sensing unit is received within and at least partially surrounded by the recess.

18. The sensing system of claim 1 , wherein the sensing unit comprises a shaft and a tip.

19. The sensing system of claim 18 , wherein the ductile layer comprises a shaft and a tip.

20. 20. The sensing system of claim 19, wherein the tip of the ductile layer protrudes beyond the tip of the sensing unit, such that the ductile layer is configured to absorb an axial insertion force applied during use.

21. A layered structure and at least one encapsulant, The layered structure is A sensing unit comprising at least one sensor having a working electrode, the sensing unit having a first outer periphery when viewed from a stacking direction of the layered structure, the sensing unit comprising a first material having a first material toughness, and a first surface and a second surface opposite to the first surface; a deformable layer positioned on the first surface of the sensing unit and configured to deform under a stress; a ductile layer positioned on the deformable layer on the opposite side to the sensing unit, the ductile layer having a second perimeter when viewed in a stacking direction of the layered structure, the first perimeter being completely contained within the second perimeter, the ductile layer comprising a second material having a second material toughness greater than the first material toughness; a sensor interface layer positioned on the second surface of the sensing unit; The at least one encapsulant is configured to at least partially encapsulate the layered structure and mechanically isolate the layered structure from an ambient environment.

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