Patent Description:
Measurement reactions using a sophisticated biomolecule identification function such as an antigen-antibody, protein-protein, and protein-DNA, etc., are becoming important techniques in clinical testing and in taking measurements in the field of biochemistry. In addition, the analysis of DNA hybridization, or DNA sequencing is also extensively used in the research field of biochemistry.

Various biochips, such as microfluidic chips, micro-array chips, or lab-on-a-chip, have been developed for biological and chemical analysis. <CIT>, for example, discloses a device for apportionment and manipulation of sample volumes into smaller discrete volumes. The compartmentalized volumes allow for isolation of samples and partitioning into a localized array that can subsequently be manipulated and analyzed. The device comprises a cavity, a surface located within the cavity, wherein the surface comprises at least one hydrophilic region; and a hydrophobic coating covering the surface except for the at least one hydrophilic region. A device with hydrophilic regions is also known from <CIT>. With the device it is possible to partition an aqueous biological liquid sample into discrete microvolumes for detection and enumeration of microorganisms. This involves distributing microvolumes of a sample to a plurality of hydrophilic liquid-retaining zones in the device, where each liquid-retaining zone is surrounded by a portion of a hydrophobic "land" area. <CIT> describes a diagnostic system that delivers a panel of serologic assay results using a small amount of blood, serum, or plasma. The system includes a disposable cartridge and a reader instrument, based on planar waveguide imaging technology. The cartridge incorporates a microarray of recombinant antigens and antibody controls in a fluidic channel. With the flourishing development of sensor devices, people have high expectation regarding the reliability, quality and cost of these biochips.

Although existing biochips have generally been adequate for their intended purposes, they have not been entirely satisfactory in all respects. For example, the fluidic velocity distribution of the sample at different reaction sites is not uniform, e.g., the fluidic velocity at the reaction sites near the center is higher than the fluidic velocity of those near the boundary. Therefore, the overall loading rates of the samples at different reaction sites are not uniform, which may cause inaccuracy of the testing results. Accordingly, there are still some problems with biochips that remain to be solved.

The present invention provides a sensor device with the features of independent claim <NUM> and a method of using the sensor device according to claim <NUM>. The sensor device includes, amongst others, a first substrate, a second substrate, a flow channel and a first reaction group. The second substrate is disposed opposite the first substrate. The flow channel is disposed between the first substrate and the second substrate, and the flow channel includes a fluidic boundary near to the edge of the flow channel. The first reaction group is disposed on the first substrate, and the first reaction group includes a first reaction site, a second reaction site and a third reaction site. The first reaction site is closer to the fluidic boundary than the second reaction site, and a size of the first reaction site is greater than a size of the second reaction site. The second reaction site is closer to the fluidic boundary than the third reaction site, and the size of the second reaction site is greater than a size of the third reaction site.

In one or more embodiments, a diameter of the first reaction site may be greater than a diameter of the second reaction site.

Preferably, the diameter of the second reaction site may be greater than a diameter of the third reaction site.

Preferably, a ratio of the diameter of the first reaction site to the diameter of the third reaction site may be in a range from <NUM>:<NUM> to <NUM>:<NUM>.

Preferably, a ratio of the diameter of the first reaction site to the diameter of the second reaction site may be in a range from <NUM>:<NUM> to <NUM>:<NUM>.

The flow channel comprises an inlet and an outlet.

Furthermore, the first reaction site and the second reaction site are on a cross-sectional line.

The cross-sectional line is perpendicular to an extending line of the inlet and the outlet.

Preferably, the sensor device may further comprise a spacer layer disposed between the first substrate and the second substrate.

Preferably, the sensor device may further comprise a first conductive layer disposed between the first substrate and the spacer layer.

Preferably, the sensor device may further comprise a second conductive layer disposed on the second substrate.

Preferably, the sensor device may further comprise a dielectric layer disposed on the first substrate and between the first substrate and the spacer layer.

Preferably, the dielectric layer may partially overlap the first reaction group.

Preferably, the first substrate may be opaque, transparent, or semi-transparent.

Preferably, the second substrate may be transparent, or semi-transparent.

Preferably, the first substrate may be a complementary metal-oxide-semiconductor (CMOS) substrate.

Preferably, the first reaction group may be modified with a self-assembly monolayer to immobilize a bio sample in a solution.

Preferably, the sensor device may further comprise a second reaction group disposed on the second substrate.

The method of using the sensor device includes, amongst others, providing a sensor device. The sensor device includes a first substrate, a second substrate, a flow channel and a first reaction group. The second substrate is disposed opposite the first substrate. The flow channel is disposed between the first substrate and the second substrate, and the flow channel includes a fluidic boundary. The first reaction group is disposed on the first substrate, and the first reaction group includes a first reaction site, a second reaction site and a third reaction site. The first reaction site is closer to the fluidic boundary than the second reaction site, and a size of the first reaction site is greater than or equal to a size of the second reaction site. The second reaction site is closer to the fluidic boundary than the third reaction site, and the size of the second reaction site is greater than a size of the third reaction site. In addition, the method also includes the following steps: loading a solution including the biosample into the flow channel; applying a voltage to the first conductive layer to immobilize the biosample on the first reaction group; turning off the voltage that is applied to the first conductive layer; and washing out excess biosample from the flow channel.

In one or more embodiments, the voltage may be a direct current voltage and the biosample may be immobilized on the first reaction group by an electrophoresis force.

In one or more embodiments, the voltage may be an alternating current voltage and the biosample may be immobilized on the first reaction group by a dielectrophoresis force.

Preferably, a frequency of the alternating current voltage may be in a range from <NUM> to <NUM>.

In one or more embodiments, after the step of applying the voltage to the first conductive layer to immobilize the biosample on the first reaction group, the method may further comprise reversing direction of the voltage to immobilize the biosample on the second reaction group.

Preferably, the step of applying the voltage to the first conductive layer to immobilize the biosample on the first reaction group, may further comprise waiting for a time period, wherein the time period is in a range from <NUM> seconds to <NUM> hours.

The disclosure may be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:.

The sensor device and the method of using the sensor device of the present disclosure are described in detail in the following description. In the following detailed description, for purposes of explanation, numerous specific details and embodiments are set forth in order to provide a thorough understanding of the present disclosure. The specific elements and configurations described in the following detailed description are set forth in order to clearly describe the present disclosure. It will be apparent, however, that the exemplary embodiments set forth herein are used merely for the purpose of illustration, and the concept of the present disclosure may be embodied in various forms without being limited to those exemplary embodiments.

In addition, the drawings of different embodiments may use like and/or corresponding numerals to denote like and/or corresponding elements in order to clearly describe the present disclosure. However, the use of like and/or corresponding numerals in the drawings of different embodiments does not suggest any correlation between different embodiments. It should be understood that this description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. The drawings are not drawn to scale. In addition, structures and devices are shown schematically in order to simplify the drawing.

In addition, the expressions "a layer overlying another layer", "a layer is disposed above another layer", "a layer is disposed on another layer" and "a layer is disposed over another layer" may indicate that the layer is in direct contact with the other layer, or that the layer is not in direct contact with the other layer, there being one or more intermediate layers disposed between the layer and the other layer.

In addition, in this specification, relative expressions are used. For example, "lower", "bottom", "higher" or "top" are used to describe the position of one element relative to another. It should be appreciated that if a device is flipped upside down, an element that is "lower" will become an element that is "higher".

It should be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers, portions and/or sections, these elements, components, regions, layers, portions and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, portion or section from another element, component, region, layer or section. Thus, a first element, component, region, layer, portion or section discussed below could be termed a second element, component, region, layer, portion or section without departing from the teachings of the present disclosure.

The terms "about" and "substantially" typically mean +/- <NUM>% of the stated value, more typically mean +/- <NUM>% of the stated value, more typically +/- <NUM>% of the stated value, more typically +/- <NUM>% of the stated value, more typically +/- <NUM>% of the stated value and even more typically +/- <NUM>% of the stated value. The stated value of the present disclosure is an approximate value. When there is no specific description, the stated value includes the meaning of "about" or "substantially".

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It should be appreciated that, in each case, the term, which is defined in a commonly used dictionary, should be interpreted as having a meaning that conforms to the relative skills of the present disclosure and the background or the context of the present disclosure, and should not be interpreted in an idealized or overly formal manner unless so defined.

In accordance with some embodiments of the present disclosure, the sensor device may include the reaction group having a larger size of reaction site near the fluidic boundary region than the center region to compensate the low sample loading rate due to the parabolic flow velocity profile in the flow channel. Therefore, the sample loading rate of the reaction sites may be uniform at different positions of the flow channel (e.g., the center region or boundary region) and reliability or performance of the sensor device may be improved. Moreover, in accordance with some embodiments, the sensor device may further include the conductive layers disposed on the substrates so that the dielectrophoretic (DEP) or electrophoretic (EP) force may be generated to assist in attracting the dielectric or charged samples to the reaction sites, respectively. The loading efficiency of the samples may be increased accordingly.

<FIG> is a schematic diagram of a sensor device <NUM> in accordance with some embodiments of the present disclosure. It should be understood that some of the components of the sensor device <NUM> are omitted in <FIG> for clarity. In addition, it should be understood that additional features may be added to the sensor device <NUM> in accordance with some embodiments of the present disclosure.

In accordance with embodiments of the present disclosure, the sensor device <NUM> may be not limited to a particular use. In accordance with some embodiments, the sensor device <NUM> may be used for biological or biochemical analysis. For example, the sensor device <NUM> may be used to measure or analyze a DNA sequence, DNA-DNA hybridization, single nucleotide polymorphisms, protein interactions, peptide interactions, antigen-antibody interactions, protein microarray, liquid biopsy, quantitative polymerase chain reaction (qPCR), glucose monitoring, cholesterol monitoring, and the like.

The sensor device <NUM> may include a first substrate <NUM>, a second substrate <NUM> and a flow channel <NUM>. The second substrate <NUM> may be disposed opposite the first substrate <NUM>. The flow channel <NUM> may be disposed between the first substrate <NUM> and the second substrate <NUM>. In accordance with some embodiments, the first substrate <NUM> and the second substrate <NUM> may be spaced apart by a distance, and the flow channel <NUM> may be the space defined between the first substrate <NUM> and the second substrate <NUM>.

In accordance with some embodiments, the material of the first substrate <NUM> and the second substrate <NUM> may include an organic material, an inorganic material, or a combination thereof. For example, the organic material may include epoxy resins, silicone resins (such as polydimethylsiloxane (PDMS)), acrylic resins (such as polymethylmetacrylate (PMMA)), polyimide (PI), polycarbonate (PC), polyethylene terephthalate (PET), per-fluoroalkoxy alkane (PFA), other suitable materials or a combination thereof, but it is not limited thereto. For example, the inorganic material may include glass, ceramic, silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, other suitable materials or a combination thereof, but it is not limited thereto. In addition, the material of the first substrate <NUM> may be the same as or different from that of the second substrate <NUM>.

In accordance with some embodiments, the first substrate <NUM> may be a complementary metal-oxide-semiconductor (CMOS) substrate. For example, the material of the first substrate <NUM> may include, but is not limited to, silicon, III-V group on silicon, graphene-on-silicon, silicon-on-insulator, or a combination thereof.

In accordance with some embodiments, the solution containing the samples to be detected or analyzed may flow through the flow channel <NUM> and the samples may be positioned on the reaction sites <NUM> (as shown in <FIG>) on the first substrate <NUM>. In addition, the flow channel <NUM> includes a fluidic boundary, and the fluidic boundary may be located at the peripheral area of the flow channel <NUM>. In other words, the fluidic boundary is near to the edge of the flow channel <NUM>. As shown <FIG>, the solution flowing in the flow channel <NUM> may present a parabolic flow velocity profile. In other words, the sample loading rate near the fluidic boundary may be lower than the center region.

In accordance with some embodiments of the present disclosure, the sensor device <NUM> may include a larger size of reaction site <NUM> near the fluidic boundary than the center region to compensate the low sample loading rate due to the parabolic flow velocity profile in the flow channel <NUM>. Specifically, refer to <FIG>, which is a top-view diagram of the first substrate <NUM> of the sensor device <NUM> in accordance with some embodiments of the present disclosure.

The sensor device <NUM> may include a plurality of first reaction groups 102R. The first reaction group 102R may be disposed on the first substrate <NUM>, and each first reaction group 102R may include a plurality of reaction sites <NUM>. In accordance with some embodiments, the reaction site <NUM> may be a nanospot or a nanowell. In accordance with some embodiments, the first reaction group 102R includes the reaction sites <NUM> that are located in the same row, and the row may be substantially perpendicular to an extending direction of the flow channel <NUM>. In accordance with the embodiments of the present disclosure, the "extending direction" of an object refers to a direction along, or substantially parallel to, the long axis of the object. For example, the object can be encircled by a minimum rectangle, and the extending direction of the long side of the minimum rectangle is the direction of the long axis.

For clear explanation, three of the reaction sites <NUM> are labeled as reaction site 102A, reaction site 102B and reaction site 102C. As shown in <FIG>, the reaction site 102A is closer to the fluidic boundary than the reaction site 102B, and the size of the reaction site 102A is greater than or equal to the size of the reaction site 102B. Moreover, the reaction site 102B is closer to the fluidic boundary than the reaction site 102C, and the size of the reaction site 102B is greater than the size of the reaction site 102C.

In accordance with some embodiments, a ratio of the area of the reaction site 102A to the area of the reaction site 102C may be in a range from <NUM>:<NUM> to <NUM>:<NUM>. In accordance with some embodiments, a ratio of the area of the reaction site 102A to the area of the reaction site 102B may be in a range from <NUM>:<NUM> to <NUM>:<NUM>. In accordance with some embodiments, the area of the reaction site <NUM> refers to the area of the bottom surface of the reaction site <NUM>.

In other words, the sizes of portions of the reaction sites <NUM> (e.g., reaction sites 102A and 102B shown in the drawing) may be gradually increased as they are getting closer to the fluidic boundary in accordance with some embodiments. On the other hand, the sizes of portions of the reaction sites <NUM> (e.g., the reaction sites 102C shown in the drawing) that are farther away from the fluidic boundary may be substantially the same in accordance with some embodiments.

Specifically, in accordance with some embodiments, a diameter d1 of the reaction site 102A is greater than or equal to a diameter d2 of the second reaction site 102B, and the diameter d2 of the reaction site 102B is greater than a diameter d3 of the reaction site 102C. In accordance with some embodiments, a ratio of the diameter d1 of the reaction site 102A to the diameter d3 of the reaction site 102C may be in a range from <NUM>:<NUM> to <NUM>:<NUM>. In accordance with some embodiments, a ratio of the diameter d1 of the reaction site 102A to the diameter d2 of the reaction site 102B may be in a range from <NUM>:<NUM> to <NUM>:<NUM>.

It should be understood that the quantity of reaction sites <NUM> is not limited to what is illustrated in the drawings. In accordance with various embodiments, there may be more or fewer reaction sites 102A (e.g., the largest reaction site), reaction sites 102B (e.g., the medium-sized reaction site), and reaction sites 102C (e.g., the smallest reaction site) may be adjusted according to need. In accordance with various embodiments, there may be a different number of sizes of reaction sites <NUM>. For example, there may be more than three sizes of reaction site <NUM>, such as four, five, six, or seven different sizes, but it is not limited thereto. In accordance with various embodiments, the reaction sites <NUM> may be arranged in a rectangular array or a hexagonal array, but it is not limited thereto.

The shape of the reaction sites <NUM> is not limited to circle, shown in <FIG>. In accordance with some other embodiments, the reaction sites <NUM> may have another suitable shape, for example, elliptical, rectangular, hexagonal, or any other suitable shape. In accordance with some embodiments, there may be more than one possible shape of reaction sites <NUM>.

Refer to <FIG>, which is a cross-sectional diagram of the sensor device <NUM> along the section line A-A' in <FIG> in accordance with some embodiments of the present disclosure. In addition, <FIG> also plots the average flow velocity of the solution containing biosamples <NUM> in the flow channel <NUM>.

As shown in <FIG>, in accordance with some embodiments, the sensor device <NUM> may further include a first spacer layer <NUM> disposed on the first substrate <NUM> and between the first substrate <NUM> and the second substrate <NUM> (as shown in <FIG>). The first spacer layer <NUM> includes a plurality of openings and the openings define the reaction sites <NUM>. Alternatively, the reaction sites <NUM> are the openings formed in the first substrate <NUM>.

In accordance with some embodiments, pitches P of the reaction sites <NUM> (the reaction sites 102A, 102B and 102C) may be the same. In accordance with some embodiments, a width W<NUM> of the first spacer layer <NUM> located between the reaction site 102A and the reaction site 102B may be smaller than a width W<NUM> of the first spacer layer <NUM> located between the reaction site 102B and the reaction site 102C. In accordance with some embodiments, the width W<NUM> and the width W<NUM> of the first spacer layer <NUM> respectively refer to the minimum width of the first spacer layer <NUM> between the reaction site 102A and the reaction site 102B and the minimum width of the first spacer layer <NUM> between the reaction site 102B and the reaction site 102C.

In accordance with some embodiments, the material of the first spacer layer <NUM> may include, but is not limited to, polyethylene terephthalate (PET), polyethylene (PE), polyethersulfone (PES), polycarbonate (PC), polymethylmethacrylate (PMMA), polydimethylsiloxane (PDMS), glass, SiO<NUM>, SiON, SiN, TiO<NUM>, TiN, Al<NUM>O<NUM>, Ta<NUM>O<NUM>, Nb<NUM>O<NUM>, or a combination thereof.

In accordance with some embodiments, the biosample <NUM> may include, but is not limited to, DNA, RNA, protein, antigen, antibody, lipid micelle, biomolecule-coated nanoparticles, or a combination thereof. In accordance with some embodiments, the reaction sites <NUM> of the first reaction group 102R may be modified with a self-assembly monolayer to immobilize the biosample <NUM> in the solution. In accordance with some embodiments, the sensor device <NUM> can measure or analyze fluorescence or chemiluminescence emitted by the biosamples <NUM>.

Specifically, in accordance with some embodiments, the reaction sites <NUM> may be selectively modified with functional groups to capture and immobilize biosamples <NUM> on the reaction sites <NUM>, and the immobilization mechanism may include surface charge attraction, self-assembled covalent binding, or bio-affinity, but it is not limited thereto. In accordance with some embodiments, when the biosample <NUM> is negatively charged, the reaction site <NUM> may be modified to be positively charged. For example, the reaction site <NUM> may be modified with silane, such as <NUM>-aminopropyltriethoxysilane (APTES) or (<NUM>-glycidyloxypropyl)triethoxysilane (GPTES). In accordance with some other embodiments, when the biosample <NUM> is modified with a biotin tag, the reaction site <NUM> may be modified with streptavidin.

As describe above, the solution flowing in the flow channel <NUM> may present a parabolic flow velocity profile, and the average flow velocity or sample loading rate at the reaction site 102A may be lower than that at the reaction site 102B. Similarly, the average flow velocity or sample loading rate at the reaction site 102B may be lower than that at the reaction site 102C. Nevertheless, since the size of the reaction site 102A or the reaction site 102B that is near the fluidic boundary is larger than the size of the reaction site 102C that is farther away from the boundary, the low sample loading rate at the reaction site 102A or the reaction site 102B can be compensated. With such a configuration, the overall loading rate (i.e. loading amount of the biosamples <NUM>) of the reaction sites <NUM> is substantially uniform in different regions of the flow channel <NUM>.

Refer to <FIG>, which are top-view diagrams of the flow channel <NUM> in accordance with some embodiments of the present disclosure. As shown in <FIG>, the flow channel <NUM> includes an inlet <NUM> and an outlet <NUM>. The solution containing the biosamples <NUM> may enter the flow channel <NUM> from the inlet <NUM> and exit the flow channel <NUM> from the outlet <NUM>. In accordance with some embodiments, the first reaction group 102R (e.g., including the reaction sites 102A, 102B and 102C as shown in <FIG>) may be located on the same cross-sectional line A-A', and the cross-sectional line A-A' may be perpendicular to an extending line Ex of the inlet <NUM> and the outlet <NUM>. The extending line Ex refers to the connection line between the center points of the inlet <NUM> and the outlet <NUM>. In accordance with some embodiments, the extending line Ex may be substantially parallel to the extending direction of the flow channel <NUM>.

As shown in <FIG>, the flow channel <NUM> may have a hexagonal shape in accordance with some embodiments. As shown in <FIG>, the flow channel <NUM> may have a leaf shape or have curved sides in accordance with some embodiments. As shown in <FIG>, the flow channel <NUM> may have an elliptical shape in accordance with some embodiments. In addition, the inlet <NUM> and the outlet <NUM> may be located on two opposite ends of the flow channel <NUM>. It should be noted that the shape of the flow channel <NUM> is not limited to those described above. In accordance with various embodiments, the flow channel <NUM> may have any other suitable shape according to need.

Refer to <FIG>, which is a cross-sectional diagram of a sensor device 10A in accordance with some embodiments of the present disclosure. As shown in <FIG>, in accordance with some embodiments, the sensor device 10A may further include a first conductive layer <NUM> and a second conductive layer <NUM>. The first conductive layer <NUM> may be disposed on the first substrate <NUM> and between the first substrate <NUM> and the first spacer layer <NUM>. The second conductive layer <NUM> may be disposed on the second substrate <NUM>. In accordance with some embodiments, the sensor device 10A may further include a second spacer layer <NUM> on the second substrate <NUM> and the second conductive layer <NUM> may be disposed between the second substrate <NUM> and the second spacer layer <NUM>.

In accordance with some embodiments, the sensor device 10A may further include a second reaction group 202R disposed on the second substrate <NUM>. The second reaction group 202R may be disposed on the second substrate <NUM>, and each second reaction group 202R may include a plurality of reaction sites <NUM>. The second reaction group 202R may be similar to the first reaction group 102R as described above, and thus will not be repeated herein. In accordance with some embodiments, the biosamples <NUM> may be positioned on the reaction sites <NUM> on the first substrate <NUM> and the reaction sites <NUM> on the second substrate <NUM>.

In accordance with some embodiments, the first substrate <NUM> and the second substrate <NUM> may be spaced a distance DS between the first substrate <NUM> and the second substrate <NUM>. In accordance with some embodiments, the distance DS may be in a range from <NUM> to <NUM>, or from <NUM> to <NUM>, for example, <NUM>, <NUM>, <NUM>, or <NUM>.

In accordance with some embodiments, the material of the first conductive layer <NUM> and the second conductive layer <NUM> may include a metal conductive material, a transparent conductive material, or a combination thereof. The metal conductive material may include copper (Cu), silver (Ag), tin (Sn), aluminum (Al), molybdenum (Mo), tungsten (W), gold (Au), chromium (Cr), nickel (Ni), platinum (Pt), titanium (Ti), copper alloy, silver alloy, tin alloy, aluminum alloy, molybdenum alloy, tungsten alloy, gold alloy, chromium alloy, nickel alloy, platinum alloy, titanium alloy, other suitable conductive materials or a combination thereof, but it is not limited thereto. The transparent conductive material may include a transparent conductive oxide (TCO). For example, the transparent conductive oxide may include indium tin oxide (ITO), tin oxide (SnO), zinc oxide (ZnO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), antimony zinc oxide (AZO) or a combination thereof, but it is not limited thereto.

In accordance with some embodiments, the first conductive layer <NUM> disposed under the reaction sites <NUM> and the second conductive layer <NUM> disposed under the reaction sites <NUM> may further provide an active force (e.g., dielectrophoretic or electrophoretic force) to attract biosamples <NUM> to the surfaces of the reaction sites <NUM> and the reaction sites <NUM>. Therefore, the loading efficiency of the biosamples <NUM> may be improved.

Refer to <FIG>, which is a cross-sectional diagram of a sensor device 10B in accordance with some other embodiments of the present disclosure. It should be understood that the same or similar components or elements in the context of the descriptions provided above and below are represented by the same or similar reference numerals. The materials, manufacturing methods and functions of these components or elements are the same as or similar to those described above, and thus will not be repeated herein.

As shown in <FIG>, in accordance with some embodiments, the sensor device 10B may include only one spacer layer. For example, in accordance with some embodiments, the sensor device 10B includes the first spacer layer <NUM> on the first conductive layer <NUM> but does not include the second spacer layer <NUM> on the second conductive layer <NUM>. In other words, the sensor device 10B includes the reaction sites <NUM> on only one side of the substrate (i.e. the first substrate <NUM>).

<FIG>, which is a cross-sectional diagram of a sensor device 10C in accordance with some other embodiments of the present disclosure. As shown in <FIG>, in accordance with some embodiments, the sensor device 10C may include a dielectric layer <NUM> disposed on the first substrate <NUM> and between the first substrate <NUM> and the first spacer layer <NUM>.

In accordance with some embodiments, the dielectric layer <NUM> may partially overlap the first reaction group 102R. In other words, the dielectric layer <NUM> may overlap with a portion of the reaction sites <NUM> but not overlap with another portion of the reaction sites <NUM>. In accordance with some embodiments, the dielectric layer <NUM> may separate the first conductive layer <NUM> apart, and the dielectric layer <NUM> may be interposed between the separated portions of the first conductive layer <NUM>. In accordance with some embodiments, the dielectric layer <NUM> may be located near the center region of the flow channel <NUM> and away from the fluidic boundary.

In accordance with some embodiments, the material of the dielectric layer <NUM> may include, but is not limited to, silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, niobium oxide, tantalum oxide, titanium oxide, titanium nitride, photoresist, polydimethylsiloxane (PDMS), polymethylmetacrylate (PMMA), polyimide (PI), other suitable materials or a combination thereof.

Refer to <FIG>, which are cross-sectional diagrams of the sensor device in accordance with some embodiments of the present disclosure. In accordance with some embodiments, the first substrate <NUM> may be opaque, transparent, or semi-transparent, and the second substrate <NUM> may be transparent, or semi-transparent. In accordance with some embodiments, the second substrate <NUM> may refer to an upper substrate of the sensor device. In accordance with some embodiments, the material of the upper substrate (e.g., the second substrate <NUM>) should be transparent or semi-transparent so that light can transmit through the upper substrate and an optical microscope <NUM> may be used to observe the biosample <NUM>.

As shown in <FIG>, in accordance with some embodiments, an optical microscope <NUM> may be used to observe the biosample <NUM> at the reaction site <NUM> on the first substrate <NUM> and the biosample <NUM> at the reaction site <NUM> on the second substrate <NUM>. In accordance with some embodiments, the observation of the biosamples <NUM> on the first substrate <NUM> and the second substrate <NUM> may be performed simultaneously. As shown in <FIG>, in accordance with some embodiments, the sensor device includes the reaction sites <NUM> only on the first substrate <NUM>, and the optical microscope <NUM> may be used to observe the biosample <NUM> at the reaction site <NUM> on the first substrate <NUM>.

Refer to <FIG>, which are cross-sectional diagrams of the sensor device in accordance with some embodiments of the present disclosure. In accordance with some embodiments, the first substrate <NUM> and/or the second substrate <NUM> may be the complementary metal-oxide-semiconductor (CMOS) substrate. In such embodiments, the first substrate <NUM> and/or the second substrate <NUM> may be opaque. In addition, as shown in <FIG>, the sensor device may further include a plurality of sensor elements <NUM>, and the sensor elements <NUM> may be disposed within the first substrate <NUM> and/or the second substrate <NUM>.

In some embodiments, the sensor element <NUM> may be a photodiode, or another suitable light sensing component that can convert measured light into current. Specifically, in accordance with some embodiments, the sensor element <NUM> may include a source and a drain of a metal-oxide-semiconductor (MOS) transistor (not illustrated) that may transfer the current to another component, such as another MOS transistor. The another component may include, but is not limited to, a reset transistor, a current source follower or a row selector for transforming the current into digital signals.

As shown in <FIG>, in accordance with some embodiments, in the sensor device 10A', both the first substrate <NUM> and the second substrate <NUM> are CMOS substrates. The sensor elements <NUM> may be disposed within the first substrate <NUM> and the second substrate <NUM> and electrically connected to the first conductive layer <NUM> and the second conductive layer <NUM> respectively.

As shown in <FIG>, in accordance with some embodiments, in the sensor device 10B', the first substrate <NUM> is a CMOS substrate while the second substrate <NUM> is not. In accordance with some embodiments, the sensor elements <NUM> may be in contact with the first conductive layer <NUM>. As shown in <FIG>, in accordance with some embodiments, in the sensor device 10C', the first substrate <NUM> is a CMOS substrate while the second substrate <NUM> is not. In accordance with some embodiments, the sensor elements <NUM> may be in contact with the first conductive layer <NUM> and the dielectric layer <NUM>.

Refer to <FIG>, which are cross-sectional diagrams of the sensor device 10A during the intermediate stages of the method of using the sensor device 10A in accordance with some embodiments of the present disclosure. It should be understood that additional operations may be provided before, during, and/or after the method of using the sensor device 10A. In accordance with some embodiments, some of the operations described below may be replaced or eliminated.

As shown in <FIG>, the method may include providing the sensor device 10A as described above, and loading a solution containing the biosamples <NUM> into the flow channel <NUM>. In accordance with some embodiments, after loading the solution containing the biosamples <NUM> into the flow channel <NUM>, the flow may be stopped and some of the biosamples <NUM> may be immobilized on the reaction sites <NUM> and the reaction sites <NUM>.

Next, referring to <FIG>, the method may include applying a voltage to the first conductive layer <NUM> to immobilize the biosample <NUM> on the reaction sites <NUM> of the first reaction group 102R. In accordance with some embodiments, the voltage may be a direct current (DC) voltage and the biosamples <NUM> may be immobilized on the reaction sites <NUM> by the electrophoresis force. As shown in <FIG>, at this stage, the first conductive layer <NUM> may be positively charged so that the negatively charged biosamples <NUM> may be attracted to the reaction sites <NUM>. In addition, the method may include turning off the voltage that is applied to the first conductive layer <NUM>.

Next, referring to <FIG>, after the step of applying the voltage to the first conductive layer <NUM> to immobilize the biosamples <NUM> on the first reaction group 102R, the method may further include reversing the direction of the voltage to immobilize the biosamples <NUM> on the reaction sites <NUM> of the second reaction group 202R. As shown in <FIG>, at this stage, the second conductive layer <NUM> may be positively charged so that the negatively charged biosamples <NUM> may be attracted to the reaction sites <NUM>. It is noted that since the biosamples <NUM> on the reaction sites <NUM> have been cross-linked to the surface of the reaction sites <NUM> via interaction of functional groups, the biosamples <NUM> that have been immobilized on the reaction sites <NUM> would not be attracted to the reaction sites <NUM>.

In addition, in accordance with some embodiments, after the step of applying the voltage to the first conductive layer <NUM> to immobilize the biosamples <NUM> on the first reaction group 102R, the method may further include waiting for a time period allowing the immobilization stable. In accordance with some embodiments, the time period may be in a range from <NUM> seconds to <NUM> hours, or from <NUM> seconds to <NUM> hours, or from <NUM> seconds to <NUM> hour, for example, <NUM> minute, <NUM> minutes, <NUM> minutes, <NUM> minutes, or <NUM> minutes.

Next, referring to <FIG>, the method may include washing out the excess biosamples <NUM> from the flow channel <NUM>. In accordance with some embodiments, a buffer solution <NUM> may be used to washing out the excess biosamples <NUM> and then refill the flow channel <NUM>. In accordance with some embodiments, the buffer solution <NUM> may be the same type of solution as the solution that contains the biosamples <NUM>. In accordance with some embodiments, the buffer solution <NUM> may include, but is not limited to, phosphate-buffered saline (PBS) or Tris-EDTA (TE) buffer.

Thereafter, as shown in <FIG>, the biosamples <NUM> may be immobilized on each reaction sites <NUM> on the first substrate <NUM> and each reaction sites <NUM> on the second substrate <NUM>. The biosamples <NUM> may be fully loaded on the reaction sites of the sensor device 10A.

It should be noted that, in accordance with the embodiments shown in <FIG>, since the first conductive layer <NUM> and the second conductive layer <NUM> are symmetric, i.e. the patterns of the first conductive layer <NUM> and the second conductive layer <NUM> that are exposed are the same, the biosamples <NUM> should be negatively charged or positively charged so that they can be attracted to the reaction sites <NUM> and <NUM> by the electrophoresis force.

Refer to <FIG>, which are cross-sectional diagrams of the sensor device 10B during the intermediate stages of the method of using the sensor device 10B in accordance with some embodiments of the present disclosure. It should be understood that additional operations may be provided before, during, and/or after the method of using the sensor device 10B. In accordance with some embodiments, some of the operations described below may be replaced or eliminated.

As shown in <FIG>, the method may include providing the sensor device 10B as described above, and loading a solution containing the biosamples <NUM> into the flow channel <NUM>. In accordance with some embodiments, after loading the solution containing the biosamples <NUM> into the flow channel <NUM>, the flow may be stopped and some of the biosamples <NUM> may be immobilized on the reaction sites <NUM>.

Next, referring to <FIG>, the method may include applying a voltage to the first conductive layer <NUM> to immobilize the biosample <NUM> on the reaction sites <NUM> of the first reaction group 102R. In accordance with some embodiments, the voltage may be an alternating current (AC) voltage and the biosamples <NUM> may be immobilized on the reaction sites <NUM> of the first reaction group 102R by a dielectrophoresis force. In accordance with some embodiments, a frequency of the alternating current voltage may be in a range from <NUM> to <NUM>, for example, <NUM>. In addition, the method may include turning off the voltage that is applied to the first conductive layer <NUM>.

Next, referring to <FIG>, the method may include washing out the excess biosamples <NUM> from the flow channel <NUM>. In accordance with some embodiments, the buffer solution <NUM> may be used to washing out the excess biosamples <NUM> and then refill the flow channel <NUM>. Thereafter, as shown in <FIG>, the biosamples <NUM> may be immobilized on each reaction sites <NUM> on the first substrate <NUM>. The biosamples <NUM> may be fully loaded on the reaction sites of the sensor device 10B.

It should be noted that, in accordance with the embodiments shown in <FIG>, since the first conductive layer <NUM> and the second conductive layer <NUM> are asymmetric, i.e. the patterns of the first conductive layer <NUM> and the second conductive layer <NUM> that are exposed are different, the biosamples <NUM> can be uncharged, negatively charged or positively charged and all of them can be attracted to the reaction sites <NUM> by the dielectrophoresis force.

Refer to <FIG>, which are cross-sectional diagrams of the sensor device 10C during the intermediate stages of the method of using the sensor device 10C in accordance with some embodiments of the present disclosure. It should be understood that additional operations may be provided before, during, and/or after the method of using the sensor device 10C. In accordance with some embodiments, some of the operations described below may be replaced or eliminated.

As shown in <FIG>, the method may include providing the sensor device 10C as described above, and loading a solution containing the biosamples <NUM> into the flow channel <NUM>. In accordance with some embodiments, after loading the solution containing the biosamples <NUM> into the flow channel <NUM>, the flow may be stopped and some of the biosamples <NUM> may be immobilized on the reaction sites <NUM> by a proper resting time. The device 10C includes a dielectric layer <NUM> under the reaction sites 102C where the average flow velocity is relatively high and uniform, and therefore, the additional electrical attraction force may not be needed.

Next, referring to <FIG>, the method may include applying a voltage to the first conductive layer <NUM> to immobilize the biosample <NUM> on the reaction sites 102A and 102B of the first reaction group 102R. In accordance with some embodiments, the voltage may be an alternating current (AC) voltage and the biosamples <NUM> may be immobilized on the reaction sites 102A and 102B of the first reaction group 102R by a dielectrophoresis force. In accordance with some embodiments, a frequency of the alternating current voltage may be in a range from <NUM> to <NUM>, for example, <NUM>. In addition, the method may include turning off the voltage that is applied to the first conductive layer <NUM>.

Next, referring to <FIG>, the method may include washing out the excess biosamples <NUM> from the flow channel <NUM>. In accordance with some embodiments, the buffer solution <NUM> may be used to washing out the excess biosamples <NUM> and then refill the flow channel <NUM>. Thereafter, as shown in <FIG>, the biosamples <NUM> may be immobilized on each reaction sites <NUM> on the first substrate <NUM> and some of the biosamples <NUM> may be located on the dielectric layer <NUM>. The biosamples <NUM> may be fully loaded on the reaction sites of the sensor device 10C.

Claim 1:
A sensor device (<NUM>), comprising:
a first substrate (<NUM>);
a second substrate (<NUM>) disposed opposite the first substrate;
a flow channel (<NUM>) disposed between the first substrate and the second substrate, the flow channel comprising a fluidic boundary near to the edge of the flow channel (<NUM>); and
a first reaction group (102R) disposed on the first substrate, the first reaction group comprising a first reaction site (<NUM>/102A), a second reaction site (<NUM>/102B) and a third reaction site (<NUM>/102C),
wherein the first reaction site is closer to the fluidic boundary than the second reaction site, and a size of the first reaction site is greater than a size of the second reaction site,
wherein the second reaction site is closer to the fluidic boundary than the third reaction site, and the size of the second reaction site is greater than a size of the third reaction site,
wherein the flow channel comprises an inlet (<NUM>) and an outlet (<NUM>),
the first reaction site and the second reaction site are on a cross-sectional line (A-A'), and
the cross-sectional line is perpendicular to an extending line (Ex) of the inlet and the outlet,
the extending line being a connection line between center points of the inlet and the outlet,
and wherein:
the reaction sites (<NUM>) are openings formed in the first substrate (<NUM>) or
the sensor device (<NUM>) further comprises a first spacer layer (<NUM>) disposed on the first substrate (<NUM>) and between the first substrate (<NUM>) and the second substrate (<NUM>) and the reaction sites (<NUM>) are defined by openings included in the first spacer layer (<NUM>).