Patent ID: 12216109

DETAILED DESCRIPTION

Hereinafter, some example embodiments are described in detail so that those skilled in the art can easily implement them. However, the actual applied structure may be implemented in various different forms and is not limited to the implementations described herein.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it may be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

Hereinafter, the term “combination” includes a mixture and two or more stacked structures.

It will be understood that elements and/or properties thereof (e.g., structures, surfaces, directions, or the like), which may be referred to as being “perpendicular,” “parallel,” “coplanar,” or the like with regard to other elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) may be “perpendicular,” “parallel,” “coplanar,” or the like or may be “substantially perpendicular,” “substantially parallel,” “substantially coplanar,” respectively, with regard to the other elements and/or properties thereof.

Elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) that are “substantially perpendicular” with regard to other elements and/or properties thereof will be understood to be “perpendicular” with regard to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances and/or have a deviation in magnitude and/or angle from “perpendicular,” or the like with regard to the other elements and/or properties thereof that is equal to or less than 10% (e.g., a. tolerance of ±10%)).

Elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) that are “substantially parallel” with regard to other elements and/or properties thereof will be understood to be “parallel” with regard to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances and/or have a deviation in magnitude and/or angle from “parallel,” or the like with regard to the other elements and/or properties thereof that is equal to or less than 10% (e.g., a. tolerance of ±10%)).

Elements and/or properties thereof (e.g., structures, surfaces, directions, or the like) that are “substantially coplanar” with regard to other elements and/or properties thereof will be understood to be “coplanar” with regard to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances and/or have a deviation in magnitude and/or angle from “coplanar,” or the like with regard to the other elements and/or properties thereof that is equal to or less than 10% (e.g., a. tolerance of ±10%)).

It will be understood that elements and/or properties thereof may be recited herein as being “the same” or “equal” as other elements, and it will be further understood that elements and/or properties thereof recited herein as being “the same” as or “equal” to other elements may be “the same” as or “equal” to or “substantially the same” as or “substantially equal” to the other elements and/or properties thereof. Elements and/or properties thereof that are “substantially the same” as or “substantially equal” to other elements and/or properties thereof will be understood to include elements and/or properties thereof that are the same as or equal to the other elements and/or properties thereof within manufacturing tolerances and/or material tolerances. Elements and/or properties thereof that are the same or substantially the same as other elements and/or properties thereof may be structurally the same or substantially the same, functionally the same or substantially the same, and/or compositionally the same or substantially the same.

It will be understood that elements and/or properties thereof described herein as being the “substantially” the same encompasses elements and/or properties thereof that have a relative difference in magnitude that is equal to or less than 10%. Further, regardless of whether elements and/or properties thereof are modified as “substantially,” it will be understood that these elements and/or properties thereof should be construed as including a manufacturing or operational tolerance (e.g., ±10%) around the stated elements and/or properties thereof.

When the terms “about” or “substantially” are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±10% around the stated numerical value. When ranges are specified, the range includes all values therebetween such as increments of 0.1%.

Hereinafter, a biosensor according to some example embodiments is described with reference to the drawings.

FIG.1is a plan view showing an example of a biosensor according to some example embodiments, andFIG.2is a cross-sectional view of the biosensor ofFIG.1taken along line II-II′.

Referring toFIGS.1and2, a biosensor10according to some example embodiments include a stretchable substrate110, a photo-detecting element310, a first light emitting element320, and a pixel defining layer (PDL)200.

The stretchable substrate110may flexibly respond to external forces or external motions such as twisting, pressing, and pulling due to relatively low stiffness and high elongation rate, and may be easily restored to the original state.

The stretchable substrate110may include an elastomer. The elastomer may include an organic elastomer, an organic-inorganic elastomer, an inorganic elastomer-like material, or a combination thereof. The organic elastomer or the organic-inorganic elastomer may be, for example, a substituted or unsubstituted polyorganosiloxane such as polydimethylsiloxane (PDMS); an elastomer including a substituted or unsubstituted butadiene moiety such as styrene-ethylene-butylene-styrene (SEBS); a polyethylene-based elastomer such as polyethylene terephthalate or polyethylene naphthalate; a polyimide-based elastomer; an elastomer including a urethane moiety; an elastomer including an acrylic moiety; an elastomer including an olefin moiety; or a combination thereof, but is not limited thereto. The inorganic elastomer-like material may include an elastic ceramic, a solid metal, a liquid metal, or a combination thereof, but is not limited thereto.

The stretchable substrate110may include regions having different stiffness, for example, a first region110A having relatively high “first” stiffness and a second region110B having a relatively lower “second” stiffness than the first region110A. Herein, the stiffness indicates a degree of resistance to deformation when a force is applied from the outside. Relatively high stiffness means that the resistance to deformation is relatively large, so that deformation is small while relatively low stiffness means that the resistance to deformation is relatively small, so that the deformation is large.

The stiffness may be evaluated from an elastic modulus, and a high elastic modulus may mean high stiffness and a low elastic modulus may mean low stiffness. The elastic modulus may be, for example, a Young's modulus. A difference between elastic moduli of the first region110A and the second region1108of the stretchable substrate110may be about 100 times or more, and the elastic modulus of the first region110A may be about 100 times higher than the elastic modulus of the second region1108. The difference between the elastic modulus of the first region110A and the second region1108may be about 100 to 100,000 times within the above range, and the elastic modulus of the first region110A may be about 100 times to about 100,000 times higher than the elastic modulus of the second region1108, but is not limited thereto. For example, the elastic modulus of the first region110A may be about 107Pa to about 1012Pa, and the elastic modulus of the second region1108may be greater than or equal to about 102Pa and less than about 107Pa, but is not limited thereto. For example, the first region110A, having a first stiffness that is greater than a second stiffness of the second region1108, may have a first elastic modulus that is greater than the elastic modulus of the second region1108(e.g., second elastic modulus).

Elongation rates of the first region110A and the second region1108of the stretchable substrate110may be different due to the aforementioned difference in stiffness, and the elongation rate of the second region1108may be higher than the elongation rate of the first region110A. Herein, the elongation rate may be a percentage of the length change that is increased to a breaking point with respect to the initial length. For example, the elongation rate of the first region110A of the stretchable substrate110may be less than or equal to about 5%, within the range, about 0% to about 5%, about 0% to about 4%, about 0% to about 3%, about 0% to about 2%, about 0% to about 1%, about 0.5% to about 5%, about 0.5% to about 4%, about 0.5% to about 3%, about 0.5% to about 2%, or about 1% to about 2%. For example, the elongation rate of the second region1108of the stretchable substrate110may be greater than or equal to about 10%, within the range, about 10% to about 300%, about 10% to about 200%, about 10% to about 100%, about 10% to about 90%, about 10% to about 80%, about 10% to about 70%, about 10% to about 60%, about 10% to about 50%, about 10% to about 40%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, or about 20% to about 40%.

The adjacent first regions110A of the stretchable substrate110may have island shapes separated from (e.g., isolated from direct contact with) each other, and a photo-detecting element310and the first light emitting element320to be described later may be disposed in the first region110A of the stretchable substrate110. For example, as shown inFIGS.1-2, the stretchable substrate110may include a plurality of first regions110A and a second region1108between adjacent first regions110A of the plurality of first regions110A, the first regions110A having a first stiffness and the second region1108having a second stiffness that is lower than the first stiffness, and where the photo-detecting element310and the first light emitting element320are on separate, respective first regions110A of the plurality of first regions110A of the stretchable substrate110.

The second region1108of the stretchable substrate110may be a region other than the plurality of first regions110A, and may be continuously connected entirely. The second region1108of the stretchable substrate110may be a region providing stretchability. Due to its relatively low stiffness and high elongation rate, the second region1108may flexibly respond to external forces or external motions such as twisting and pulling, and may be easily restored to its original state.

For example, the first region110A and the second region1108of the stretchable substrate110may have different shapes. For example, the first region110A of the stretchable substrate110may be flat and the second region1108may include a two-dimensional or three-dimensional stretchable structure. The two-dimensional or three-dimensional stretchable structure may have, for example, a wavy shape, a wrinkle shape, a pop-up shape, or a non-coplanar mesh shape, but is not limited thereto.

For example, the first region110A and the second region1108of the stretchable substrate110may include different materials. For example, the first region110A of the stretchable substrate110may include an inorganic material, an organic material and/or an organic/inorganic material having relatively high stiffness and a low elongation rate, and the second region1108of the stretchable substrate110may include an inorganic material, an organic material and/or an organic/inorganic material having a relatively low stiffness and high elongation rate. For example, the first region110A of the stretchable substrate110may include an organic material such as polycarbonate, polymethylmethacrylate, polyethyleneterephthalate, polyethylenenaphthalate, polyimide, polyamide, polyamideimide, polyethersulfone, or a combination thereof, a carbon structure such as diamond carbon and the second region1108of the stretchable substrate110may include an organic or organic/inorganic elastomer such as a substituted or unsubstituted polyorganosiloxane such as polydimethylsiloxane, an elastomer including a substituted or unsubstituted butadiene moiety such as styrene-ethylene-butylene-styrene, an elastomer including a urethane moiety, an elastomer including an acrylic moiety, an elastomer including an olefin moiety, or a combination thereof; an inorganic elastomer-like material such as ceramic, a solid metal, a liquid metal, or a combination thereof, but they are not limited thereto.

For example, the first region110A and the second region1108of the stretchable substrate110may be formed with (e.g., at least partially comprise) the same material, and may have different stiffness by different conditions such as polymerization degrees and/or curing degrees. For example, the stretchable substrate110may have the first region110A having a relatively high stiffness and the second region1108having a relatively low stiffness which are formed by varying the polymerization degrees, types and contents of curing agents, and/or curing temperatures, based on polydimethylsiloxane.

In this way, the stretchable substrate110includes the first region110A having relatively high stiffness and a low elongation rate and the second region1108having relatively low stiffness and a high elongation rate, and the photo-detecting element310and the first light emitting element320are disposed in the first region110A, and thereby when a large external force or motion is applied to the stretchable substrate110, the photo-detecting element310and the first light emitting element320in the first region110A receives relatively smaller strain, and thus may be at least partially protected from, or prevented from, being damaged or destroyed due to the extreme strain.

A photo-detecting element310and a first light emitting element320are disposed on the stretchable substrate110. The photo-detecting element310and the first light emitting element320are separated (e.g., isolated from direct contact with each other) by a particular (or, alternatively, predetermined) interval.

The photo-detecting element310may include a first electrode410and a second electrode420facing each other, and a photoelectric conversion layer500between the first electrode410and the second electrode420, wherein the area310A of an active region of the photo-detecting element310(e.g., the active region of the photo-detecting element310may be defined as a region where the first and second electrodes410and420and the photoelectric conversion layer500overlap in the vertical direction perpendicular to the upper surface110S) may be substantially equal to the area211A of the first opening211, where “area” refers to an area in a plane that is parallel to the in-plane direction of the stretchable substrate110(e.g., a plane that is parallel to the upper surface110S of the stretchable substrate110). As shown inFIG.2, the photo-detecting element310may be at least partially in the first opening211based on a first electrode410, second electrode420, and photoelectric conversion layer500at least partially covering one or more surfaces of the first opening211, which may include the upper surface110S of the stretchable substrate110that is exposed by the first opening211and/or one or more inner surfaces of the first pixel defining layer210that at least partially define the first opening211.

The photo-detecting element310is configured to convert an optical signal (e.g., incident light) into an electrical signal.

The photoelectric conversion layer500may be configured to absorb light of at least a portion of a visible light wavelength spectrum, for example, and absorb light of at least one of a blue wavelength spectrum, a green wavelength spectrum, or a red wavelength spectrum. The blue wavelength spectrum may, for example, have a maximum absorption wavelength (λmax) at greater than or equal to about 400 nm and less than about 500 nm, the green wavelength spectrum may have a maximum absorption wavelength (λmax) at about 500 nm to about 600 nm, and the red wavelength spectrum may have a maximum absorption wavelength (λmax) at greater than about 600 nm and less than or equal to about 700 nm. As an example, the photoelectric conversion layer500may be configured to absorb light of the blue wavelength spectrum, the green wavelength spectrum, and the red wavelength spectrum, that is, the light of an entire visible wavelength spectrum, for example, may be configured to absorb white light. The photoelectric conversion layer500configured to absorb white light may be formed by blending, for example, a blue light absorbing material, a green light absorbing material, and a red light absorbing material, or by stacking a blue light absorbing layer, a green light absorbing layer, and a red light absorbing layer.

The photoelectric conversion layer500may include an organic light absorbing material, an inorganic light absorbing material, and/or an organic/inorganic light absorbing material. The organic light absorbing material may be a low molecular weight light absorbing material and/or a polymer light absorbing material and the inorganic light absorbing material may be a semiconductor compound, a quantum dot, and/or a perovskite, but they are not limited thereto.

One of the first electrode410or the second electrode420may be an anode and the other may be a cathode. For example, the first electrode410may be an anode and the second electrode420may be a cathode. For example, the first electrode410may be a cathode and the second electrode420may be an anode.

The first electrode410may be a reflective electrode and the second electrode420may be a transflective electrode. The reflective electrode may be made of, for example, an opaque conductor or may include a reflective layer including an opaque conductor. The reflective electrode may have a light transmittance of less than about 10%, for example, a light transmittance of less than or equal to about 8%, less than or equal to about 7%, less than or equal to about 5%, less than or equal to about 3%, or less than or equal to about 1%, and the light transmittance may be equal to or greater than about 0%, 0.1%, 0.5%, or the like. The reflective electrode has a reflectance of greater than or equal to about 10%, and may have a reflectance of, for example, greater than or equal to about 20%, greater than or equal to about 30%, greater than or equal to about 50%, or greater than or equal to about 70%, and the reflectance may be equal to or less than about 100%, 99.9%, 99.5%, or the like. The transflective electrode may have light transmittance between the transparent electrode and the reflective electrode, and may have a light transmittance of about 10% to about 70%, about 20% to about 60%, or about 30% to about 50%.

At least one of the first electrode410or the second electrode420may be a stretchable electrode. For example, each of the first electrode410and the second electrode420may be a stretchable electrode.

The stretchable electrode may include, for example, a stretchable conductor or may be formed into a stretchable shape. The stretchable conductor may include, for example, a liquid metal, a conductive nanostructure, or a combination thereof.

The liquid metal may be an alloy composed of a plurality of metals and/or semi-metals, and may exist in a liquid state at room temperature (about 25° C.). The liquid metal may be an alloy including at least one selected from, for example, copper (Cu), titanium (Ti), nickel (Ni), zirconium (Zr), iron (Fe), magnesium (Mg), calcium (Ca), cobalt (Co), palladium (Pd), platinum (Pt), gold (Au), cerium (Ce), lanthanum (La), yttrium (Y), gadolinium (Gd), beryllium (Be), tantalum (Ta), gallium (Ga), indium (In), aluminum (Al), hafnium (Hf), niobium (Nb), lead (Pb), platinum (Pt), silver (Ag), phosphorus (P), boron (B), silicon (Si), carbon (C), tin (Sn), molybdenum (Mo), tungsten (W), zinc (Zn), manganese (Mn), erbium (Er), chromium (Cr), praseodymium (Pr), thulium (Tm), and/or a combination thereof, but is not limited thereto.

The conductive nanostructure may include, for example, a conductive nanoparticle, a conductive nanoflake, a conductive nanowire, a conductive nanotube, or a combination thereof, for example a nanoparticle, a nanoflake, nanowire, a nanotube or a combination thereof including a low-resistance conductor such as silver, gold, copper, aluminum, and the like or a carbon conductor, and for example a silver nanoparticle, a silver nanoflake, a silver nanowire, a silver nanotube, a carbon nanotube, graphene, graphite, or a combination thereof, but is not limited thereto.

The stretchable shape may be, for example, a wavy shape, a wrinkle shape, a popup shape, or a non-coplanar mesh shape, but is not limited thereto.

For example, each of the first electrode410and the second electrode420may be a stretchable electrode including a liquid metal, wherein the first electrode410, which is a reflective electrode, may have a sufficient thickness of greater than or equal to about 80 nm and the second electrode420, which is a transflective electrode, may have a thickness thinner than that of the reflective electrode, and may have, for example, a thickness of about 5 nm to about 50 nm.

The first light emitting element320includes a third electrode430and a fourth electrode440facing each other, and a first light emitting layer610between the third electrode430and the fourth electrode440, and the area320A of the active region (e.g., light emitting area) of the first light emitting element320(e.g., the active region of the photo-detecting element310and/or light emitting area thereof may be defined as a region where the third and fourth electrodes430and440and the first light emitting layer610overlap in the vertical direction perpendicular to the upper surface110S) may be substantially equal to the area212A of the second opening212, where “area” refers to an area in a plane that is parallel to the in-plane direction of the stretchable substrate110(e.g., a plane that is parallel to the upper surface110S of the stretchable substrate110). As shown inFIG.2, the first light emitting element320may be at least partially in the second opening212based on the third electrode430, fourth electrode440, and first light emitting layer610at least partially covering one or more surfaces of the second opening212, which may include the upper surface110S of the stretchable substrate110that is exposed by the second opening212and/or one or more inner surfaces of the second pixel defining layer220that at least partially define the second opening212.

The first light emitting element320may be configured to convert an electrical signal into an optical signal (e.g., emitted light), and may be, for example, a light emitting diode, and the light emitting diode may be, for example, an organic light emitting diode, a quantum dot light emitting diode, or a perovskite light emitting diode.

The first light emitting layer610may be configured to emit light of, for example, at least a portion of a visible light wavelength spectrum, for example, and may be configured to emit light of at least one of a blue wavelength spectrum, a green wavelength spectrum, or a red wavelength spectrum. The blue wavelength spectrum may, for example, have a maximum emission wavelength (λmax) at greater than or equal to about 400 nm and less than about 500 nm, the green wavelength spectrum may have a maximum emission wavelength (λmax) at about 500 nm to about 600 nm, and the red wavelength spectrum may have be a maximum emission wavelength (λmax) at greater than about 600 nm and less than or equal to about 700 nm. As an example, the first light emitting layer610may be configured to emit light of the blue wavelength spectrum, the green wavelength spectrum, and the blue wavelength spectrum, that is, the light of an entire visible wavelength spectrum, for example, may be configured to emit white light. The first light emitting layer610configured to emit white light may be formed by blending, for example, a blue light emitting material, a green light emitting material, and a red light emitting material, or may be formed by stacking a blue light emitting layer, a green light emitting layer, and a red light emitting layer.

The first light emitting layer610may include an organic light emitting material, an inorganic light emitting material, and/or an organic/inorganic light emitting material. The organic light emitting material may be a low molecular light emitting material and/or a polymer light emitting material, and the inorganic light emitting material may be a semiconductor compound, a quantum dot, and/or perovskite, but are not limited thereto.

The third electrode430and the fourth electrode440may be the same as the first electrode410and the second electrode420described above.

The pixel defining layer200is formed on (e.g., directly or indirectly on) the stretchable substrate110, and may define a region of the photo-detecting element310and a region of the first light emitting element320, respectively. The pixel defining layer200may include a first pixel defining layer210for defining the region of the photo-detecting element310and a second pixel defining layer220for defining the region of the first light emitting element320, and the first pixel defining layer210may have (e.g., include one or more inner surfaces that at least partially define) a first opening211where the photo-detecting element310is disposed, and the second pixel defining layer220may have (e.g., include one or more inner surfaces that at least partially define) a second opening212where the first light emitting element320is disposed. As shown, the first opening211may be at least partially defined by one or more inner surfaces of the first pixel defining layer210and may be further defined by a portion of the upper surface110S of the stretchable substrate110that is exposed by the first opening211(e.g., a portion of an upper surface of the first region110A of the stretchable substrate110). As shown, the second opening212may be at least partially defined by one or more inner surfaces of the second pixel defining layer220and may be further defined by a portion of the upper surface110S of the stretchable substrate110that is exposed by the second opening212(e.g., a portion of an upper surface of a separate first region110A of the stretchable substrate110). As shown, the first and second openings211and212extend through the respective thicknesses of the first and second pixel defining layers210and220in a vertical direction that extends perpendicular to the upper surface110S of the stretchable substrate110(e.g., perpendicular to the in-plane direction of the stretchable substrate110).

As shown, the photo-detecting element310may be at least partially located within the first opening211, where portions of the photo-detecting element310may or may not extend, in a direction parallel to the upper surface110S, beyond the boundaries of the first opening211. For example, as shown inFIG.2, portions of the first and second electrodes410and420and the photoelectric conversion layer500may extend in the direction parallel to the upper surface110S beyond the lateral boundaries of the first opening211as at least partially defined by one or more inner surfaces of the first pixel defining layer210. However, example embodiments are not limited thereto, and in some example embodiments the first and second electrodes410and420and the photoelectric conversion layer500may be entirely located within the first opening211and may not extend beyond the first opening211in the direction parallel to the upper surface110S.

As shown, first light emitting element320may be at least partially located within the second opening212, where portions of the first light emitting element320may or may not extend, in a direction parallel to the upper surface110S, beyond the boundaries of the second opening212. For example, as shown inFIG.2, portions of the third and fourth electrodes430and440and the first light emitting layer610may extend in the direction parallel to the upper surface110S beyond the lateral boundaries of the first opening212as at least partially defined by one or more inner surfaces of the second pixel defining layer220. However, example embodiments are not limited thereto, and in some example embodiments the third and fourth electrodes430and440and the first light emitting layer610may be entirely located within the second opening212and may not extend beyond the second opening212in the direction parallel to the upper surface110S.

As shown inFIGS.1-2, the first pixel defining layer210and the second pixel defining layer220may be disposed in parallel along the in-plane direction of the stretchable substrate110(where the in-plane direction of the stretchable substrate110may be parallel to the upper surface110S of the stretchable substrate110), and may be, for example, continuously and adjacently disposed. The boundary of the first pixel defining layer210and the second pixel defining layer220may be between the first opening211and the second opening212, and may be, for example, a half point of the gap between the edge of the first opening211and the edge of the second opening212facing each other. For example, as shown inFIG.1, the boundary290(e.g., interface) between the first and second pixel defining layers210and220that are directly connected to each other (e.g., in direct contact with each other) may be located a distance211E in the in-plane direction of the stretchable substrate110(e.g., parallel to the upper surface110S) from a proximate edge of the first opening211and may be located a distance212E in the in-plane direction of the stretchable substrate110(e.g., parallel to the upper surface110S) from a proximate edge of the second opening212, where distances211E and212E may be equal to each other, and where the distances211E and212E may be one half the distance290D (e.g., gap) in the in-plane direction of the stretchable substrate110(e.g., parallel to the upper surface110S) between respective edges of the first and second opening211and212facing each other. Accordingly, the boundary290may be located halfway along the gap (e.g., distance290D). In some example embodiments, a magnitude of the gap (e.g., distance290D) between the edge of the first opening211and the edge of the second opening212facing each other may be about 0.4 times to about 4 times of a magnitude of the width211D of the first opening211(e.g., distance between opposing edges of the first opening211in the direction parallel to the direction of distance290D) or a magnitude of the width212D of the second opening212(e.g., distance between opposing edges of the second opening212in the direction parallel to the direction of distance290D).

In general, in order to realize high-performance biosensor signal characteristics with a signal to noise ratio (SNR) of greater than or equal to about 15 dB, it is necessary to maintain a gap between the photo-detecting element310and the first light emitting element320in an appropriate range. The gap between the edge of the first opening211and the edge of the second opening212which include the photo-detecting element310and the first light emitting element320, respectively is set to an appropriate range (optimum distance). If the gap is too narrow or wide, the signal sensitivity characteristics may be deteriorated. As described above, when the gap between the edge of the first opening211and the edge of the second opening212is about 0.4 times to about 4 times, for example, about 0.6 times to about 4 times, about 0.8 times to about 4 times, about 1.0 times to about 4 times, about 0.4 times to about 3.8 times, about 0.4 times to about 3.6 times, about 0.4 times to about 3.4 times, about 0.4 times to about 3.2 times, or about 0.4 times to about 3.0 times the width of the first opening211or the second opening212, a biosensor having excellent signal sensitivity may be implemented.

The pixel defining layer200may include an organic material, an inorganic material, and/or an organic-inorganic material, and may include, for example, a photosensitive organic polymer. The photosensitive organic polymer may include, for example, polymethyl methacrylate (PMMA), polyimide (PI), and the like, but is not limited thereto. The pixel defining layer may be formed through, for example, photolithography, and accordingly the area210A of the first pixel defining layer210, the area220A of the second pixel defining layer220, the area211A of the first opening211and/or the area212A of the second opening212may be effectively adjusted. In addition, the distance between the photo-detecting element310and the first light emitting element320may be controlled by adjusting the area of the pixel defining layer when forming the biosensor, so that the signal sensitivity of the biosensor may be improved.

The pixel defining layer200may be in contact (e.g., direct contact) with the stretchable substrate110, and may be, for example, in contact with the whole region excluding portions of contacting the first electrode410of the photo-detecting element310and the third electrode430of the first light emitting element320. As shown inFIG.2, for example, a portion (e.g., some or all) of the first pixel defining layer210excluding the first opening211may be in direct contact with the stretchable substrate110. InFIG.2, a portion of the first pixel defining layer210excluding the first opening211may be isolated from direct contact with the stretchable substrate110by a portion of the first electrode410, but in some example embodiments, all of the first pixel defining layer210excluding the first opening211may be in direct contact with the stretchable substrate110. As shown inFIG.2, for example, a portion (e.g., some or all) of the second pixel defining layer220excluding the second opening212may be in direct contact with the stretchable substrate110. InFIG.2, a portion of the second pixel defining layer220excluding the second opening212may be isolated from direct contact with the stretchable substrate110by a portion of the third electrode430, but in some example embodiments, all of the second pixel defining layer220excluding the second opening212may be in direct contact with the stretchable substrate110.

The pixel defining layer200may be formed in a sufficiently wide area (e.g., area of sufficiently great magnitude) on the stretchable substrate110, and accordingly the pixel defining layer200is at least partially protected from, or prevented from, being lifted or delaminated from the stretchable substrate110.

One example method of manufacturing elements including the aforementioned stretchable substrate110may include forming a flexible stretchable substrate110on a rigid support substrate such as a glass substrate in terms of ease and stability of the process; forming a pixel defining layer200, a photo-detecting element310, and a first light emitting element320on the stretchable substrate110; and separating the stretchable substrate110from the support substrate through a wet process. The wet process may be, for example, a method of weakening adherence between the support substrate and the stretchable substrate110to separate the stretchable substrate110from the support substrate by, for example, dipping the support substrate formed with the elements into liquid such as water or supplying liquid such as water by a method of spraying or coating to remove a sacrificial layer between the support substrate and the stretchable substrate110.

When the stretchable substrate110is separated through the wet process, the elements may be applied with the particular (or, alternatively, predetermined) strain stress during separating the stretchable substrate110from the support substrate, and thus the elements may be lifted and/or delaminated from the stretchable substrate110by the strain stress, or the performance of the element may be deteriorated. But in a case of the biosensor10according to some example embodiments, the pixel defining layer200on the stretchable substrate110is formed in a sufficiently wide (e.g., sufficiently great) area, so that the stability of the elements on the stretchable substrate110may be enhanced during the separating the stretchable substrate110from the support substrate, thereby the strain stress applied to the elements may be reduced or removed, and the elements may be at least partially protected from, or prevented from, being lifted and/or delaminated, and so resultantly, the deterioration of performance of the biosensor10may be reduced or prevented.

In order to effectively reduce or reduce or prevent the lifting and/or delaminating the element during the process, some example embodiments may provide sufficient area of the pixel defining layer on the stretchable substrate110, for example, may provide the pixel defining layer with the sufficiently wider (e.g., greater) area than the area of the first and second openings211and212.

The area210A of the first pixel defining layer210may be, for example, about twice or more (e.g., equal to or greater than about 2 times), for example, about 2.4 times or more, about 2.5 times or more, about 3 times or more, about 4 times or more, about 5 times or more, about 6 times or more, about 7 times or more, about 8 times or more, about 9 times or more, or about 10 times or more, for example about 2.4 times to about 25 times, about 2.4 times to about 24 times, about 2.4 times to about 23 times, about 2.4 times to about 22 times, about 2.4 times to about 21 times, about 2.4 times to about 20 times, about 2.4 times to about 19 times, about 2.4 times to about 18 times, about 2.4 times to about 17 times, about 2.4 times to about 16 times, about 2.4 times to about 15 times, about 2.5 times to about 25 times, about 3 times to about 25 times, about 4 times to about 25 times, about 5 times to about 25 times, about 6 times to about 25 times, about 7 times to about 25 times, about 8 times to about 25 times, about 9 times to about 25 times, about 10 times to about 25 times wider (e.g., greater) than the area211A of the first opening211, but the present inventive concepts are not limited thereto.

In some example embodiments, and as shown in at leastFIGS.1-2, the area210A of the first pixel defining layer210means an area including all the areas of the first opening211and the first pixel defining layer210excluding the area211A of the first opening211, where “area” refers to an area in a plane that is parallel to the in-plane direction of the stretchable substrate110(e.g., a plane that is parallel to the upper surface110S of the stretchable substrate110).

As in above, the strain stress generated during the wet peeling of the stretchable substrate110may be reduced by securing the area of the first pixel defining layer210, and according to reducing the strain stress, the deterioration of the stability and the signal sensitivity of the elements of the biosensor after peeling may be reduced or prevented.

Meanwhile, the first opening211is empty space where the first pixel defining layer210is not formed, so it is needed to secure the sufficient area of the first pixel defining layer210relative to the first opening211. For example, the area210A of the first pixel defining layer210excluding the first opening211(e.g., area217A) may be wider (e.g., greater) than the area of the first opening211. Restated, area217A, which may be a difference between areas210A and211A, may be greater than area211A. When the area of the pixel defining layer210excluding the first opening211is smaller than the area of the first opening211(e.g., when area217A, which may be a difference between areas210A and211A, is smaller than area211A), the performance of the elements may be significantly deteriorated because the strain stress is not properly controlled during the process of peeling through the wet process.

For example, the area of the first pixel defining layer210excluding the first opening211(e.g., area217A) may be about 1.1 times or more, for example, about 1.1 times or more, about 1.2 times or more, about 1.3 times or more, about 1.4 times or more, about 1.5 times or more, about 1.6 times or more, about 1.7 times or more, about 1.8 times or more, about 1.9 times or more, about 2.0 times or more, about 3 times or more, about 4 times or more, about 5 times or more, about 6 times or more, about 7 times or more, about 8 times or more, about 9 times or more or about 10 times or more, for example about 1.1 times to about 24 times, about 1.1 times to about 23 times, about 1.1 times to about 22 times, about 1.1 times to about 21 times, about 1.1 times to about 20 times, about 1.1 times to about 19 times, about 1.1 times to about 18 times, about 1.1 times to about 17 times, about 1.1 times to about 16 times, about 1.1 times to about 15 times, about 1.1 times to about 24 times, about 1.3 times to about 24 times, about 1.5 times to about 24 times, about 1.7 times to about 24 times, about 1.9 times to about 24 times, about 2 times to about 24 times, about 3 times to about 24 times, about 4 times to about 24 times, about 5 times to about 24 times, about 6 times to about 24 times, about 7 times to about 24 times, about 8 times to about 24 times, about 9 times to about 24 times, or about 10 times to about 24 times wider (e.g., greater) than the area of the first opening211, but the present inventive concepts are not limited thereto.

The descriptions for the aforementioned first pixel defining layer210and first opening211may be equally applied to the second pixel defining layer220and the second opening212.

For example, the area220A of the second pixel defining layer220may be about twice or more (e.g., equal to or greater than about 2 times), for example, about 2.4 times or more, about 2.5 times or more, about 3 times or more, about 4 times or more, about 5 times or more, about 6 times or more, about 7 times or more, about 8 times or more, about 9 times or more, or about 10 times or more, for example about 2.4 times to about 25 times, about 2.4 times to about 24 times, about 2.4 times to about 23 times, about 2.4 times to about 22 times, about 2.4 times to about 21 times, about 2.4 times to about 20 times, about 2.4 times to about 19 times, about 2.4 times to about 18 times, about 2.4 times to about 17 times, about 2.4 times to about 16 times, about 2.4 times to about 15 times, about 2.5 times to about 25 times, about 3 times to about 25 times, about 4 times to about 25 times, about 5 times to about 25 times, about 6 times to about 25 times, about 7 times to about 25 times, about 8 times to about 25 times, about 9 times to about 25 times, about 10 times to about 25 times wider (e.g., greater) than the area212A of the second opening212, but the present inventive concepts are not limited thereto.

The second opening212is empty space where the second pixel defining layer220is not formed, and thus it is needed to secure the sufficient area of the second pixel defining layer220relative to the second opening212. For example, the area of the second pixel defining layer220excluding the second opening212(e.g., area227A, which may be a difference between areas220A and212A) may be wider (e.g., the area may be greater in magnitude) than the area212A of the second opening212. For example, the area220A of the second pixel defining layer220excluding the second opening212(e.g., area227A, which may be a difference between areas220A and212A) may be about 1.1 times or more, about 1.2 times or more, about 1.3 times or more, about 1.4 times or more, about 1.5 times or more, about 1.6 times or more, about 1.7 times or more, about 1.8 times or more, about 1.9 times or more, about 2.0 times or more, about 3 times or more, about 4 times or more, about 5 times or more, about 6 times or more, about 7 times or more, about 8 times or more, about 9 times or more, or about 10 times or more, for example, about 1.1 times to about 24 times, about 1.1 times to about 23 times, about 1.1 times to about 22 times, about 1.1 times to about 21 times, about 1.1 times to about 20 times, about 1.1 times to about 19 times, about 1.1 times to about 18 times, about 1.1 times to about 17 times, about 1.1 times to about 16 times, about 1.1 times to about 15 times, about 1.2 times to about 24 times, about 1.3 times to about 24 times, about 1.5 times to about 24 times, about 1.7 times to about 24 times, about 1.9 times to about 24 times, about 2 times to about 24 times, about 3 times to about 24 times, about 4 times to about 24 times, about 5 times to about 24 times, about 6 times to about 24 times, about 7 times to about 24 times, about 8 times to about 24 times, about 9 times to about 24 times, or about 10 times to about 24 times wider (e.g., greater) than the area of the second opening212, but the present inventive concepts are not limited thereto.

Similarly, for example, the entire area of the pixel defining layer200including the first pixel defining layer210and the second pixel defining layer220(e.g., a sum of areas210A and220A) may be about twice or more (e.g., equal to or greater than about twice), for example, about 2.4 times or more, about 2.5 times or more, about 3 times or more, about 4 times or more, about 5 times or more, about 6 times or more, about 7 times or more, about 8 times or more, about 9 times or more, or about 10 times or more, for example about 2.4 times to about 25 times, about 2.4 times to about 24 times, about 2.4 times to about 23 times, about 2.4 times to about 22 times, about 2.4 times to about 21 times, about 2.4 times to about 20 times, about 2.4 times to about 19 times, about 2.4 times to about 18 times, about 2.4 times to about 17 times, about 2.4 times to about 16 times, about 2.4 times to about 15 times, about 2.5 times to about 25 times, about 3 times to about 25 times, about 4 times to about 25 times, about 5 times to about 25 times, about 6 times to about 25 times, about 7 times to about 25 times, about 8 times to about 25 times, about 9 times to about 25 times, about 10 times to about 25 times wider (e.g., greater) than the areas of the first and second openings211and212(e.g., the sum of areas211A and212A), but the present inventive concepts are not limited thereto.

On the pixel defining layer200, the photo-detecting element310, and the first light emitting element320, an encapsulant700is formed.

The encapsulant700may protect the photo-detecting element310, the first light emitting element320and the pixel defining layer200, and effectively block or reduce or prevent inflow of oxygen, moisture and/or contaminants from the outside. For example, the encapsulant700may reduce or prevent inflow of biological secretions such as sweats into the biosensor10and thus degradation of the biosensor10.

The encapsulant700may cover the whole surface of the stretchable substrate110. However, the present inventive concepts are not limited thereto, and the encapsulant700may be disposed separately on the first region110A of the stretchable substrate110, and each encapsulant700individually may cover the photo-detecting element310, the first light emitting element320, and the pixel defining layer.

The encapsulant700may include, for example, an organic material, an inorganic material, and/or an organic/inorganic material, and may include one or more layers. For example, the encapsulant700may include an oxide, a nitride, and/or an oxynitride, for example an oxide, a nitride, and/or an oxynitride including at least one of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), or silicon (Si). For example, the encapsulant700may include layers having different refractive indexes that are alternately stacked. For example, a first layer including a first material selected from an oxide, a nitride, and an oxynitride, and a second layer including a second material selected from an oxide, a nitride, and an oxynitride having a higher refractive index than the first material may be alternately stacked.

FIG.3is a plan view showing another example of a biosensor according to some example embodiments, andFIG.4is a cross-sectional view of the biosensor ofFIG.3taken along line IV-IV′.

Referring toFIGS.3and4, the biosensor10according to some example embodiments includes a stretchable substrate110having a first region110A and a second region110B, a photo-detecting element310including a first electrode410, a photoelectric conversion layer500, and a second electrode420; a first light emitting element320including a third electrode430, a first light emitting layer610, and a fourth electrode440; a pixel defining layer200having first and second openings211and212; and an encapsulant700, like some example embodiments, including the example embodiments shown inFIGS.1and2.

However, in the biosensor10according to some example embodiments, the first pixel defining layer210and the second pixel defining layer220may be separated from each other and may be disposed in an island shape, unlike some example embodiments, including the example embodiments shown inFIGS.1and2. Restated, and as shown inFIGS.3-4, the first pixel defining layer210and the second pixel defining layer220may be isolated from direct contact with each other, for example by at least a portion of the encapsulant700as shown inFIG.4which may extend vertically between the first pixel defining layer210and the second pixel defining layer220to directly contact the upper surface110S of the stretchable substrate110(e.g., an upper surface of at least a portion of a second region110B). As the first pixel defining layer210and the second pixel defining layer220are separated as described above, flexibility of the biosensor10may be further increased.

FIG.5is a plan view showing another example of a biosensor according to some example embodiments, andFIG.6is a cross-sectional view of the biosensor ofFIG.5taken along the line VI-VI′.

Referring toFIGS.5and6, the biosensor10according to some example embodiments includes a stretchable substrate110having a first region110A and a second region110B, a photo-detecting element310including a first electrode410, a photoelectric conversion layer500, and a second electrode420; a first light emitting element320including a third electrode430, a first light emitting layer610, and a fourth electrode440; a pixel defining layer200having first and second openings211and212; and an encapsulant700, like some example embodiments, including the example embodiments shown inFIGS.1and2.

However, in the biosensor10according to some example embodiments, unlike some example embodiments, including the example embodiments shown inFIGS.1and2, the pixel defining layer200may further include a third pixel defining layer230having (e.g., including one or more inner surfaces that at least partially define) a third opening213and a second light emitting element330in (e.g., at least partially in) the third opening213.

As shown, the third opening213may be at least partially defined by one or more inner surfaces of the third pixel defining layer230and may be further defined by a portion of the upper surface110S of the stretchable substrate110that is exposed by the third opening213(e.g., a portion of an upper surface of the first region110A of the stretchable substrate110). As shown, the third opening213may extend through the thickness of the third pixel defining layers230in a vertical direction that extends perpendicular to the upper surface110S of the stretchable substrate110(e.g., perpendicular to the in-plane direction of the stretchable substrate110).

The second light emitting element330may include a fifth electrode450, a sixth electrode460, and a second light emitting layer620between the fifth electrode450and the sixth electrode460, and the light emitting area (320A) of the second light emitting element330may be substantially equal to the area213A of the third opening213.

Meanwhile, the descriptions on the first electrode410and the second electrode420may be equally applied to the fifth electrode450and the sixth electrode460.

As shown, the second light emitting element330may be at least partially located within the third opening213, where portions of the second light emitting element330may or may not extend, in a direction parallel to the upper surface110S, beyond the boundaries of the third opening213. For example, as shown inFIG.6, portions of the fifth and sixth electrodes450and460and the second light emitting layer620may extend in the direction parallel to the upper surface110S beyond the lateral boundaries of the third opening213as at least partially defined by one or more inner surfaces of the third pixel defining layer230. However, example embodiments are not limited thereto, and in some example embodiments the fifth and sixth electrodes450and460and the second light emitting layer620may be entirely located within the third opening213and may not extend beyond the third opening213in the direction parallel to the upper surface110S.

The second light emitting layer620of the second light emitting element330may be configured to emit light in a different wavelength spectrum from the light emitted by the first light emitting layer610of the first light emitting element320. The second light emitting element330may thus be configured to emit light having a different wavelength spectrum from light emitted by the first light emitting element320. For example, the first light emitting layer610of the first light emitting element320may be a green light emitting element configured to emit light in a green wavelength spectrum; and the second light emitting layer620of the second light emitting element330may be a red light emitting element configured to emit light in a red wavelength spectrum, or an infrared light emitting element configured to emit light in an infrared wavelength spectrum. The green light emitting element and the red/infrared light emitting element may be, for example, employed for the absorption and/or reflection characteristics of oxyhemoglobin (HbO2) and hemoglobin (Hb) in the blood vessels.

Like the aforementioned first pixel defining layer210and second pixel defining layer220, the third pixel defining layer230may have a sufficiently large area230A. For example, the area230A of the third pixel defining layer230may be twice or more (e.g., may be equal to or greater than twice), for example, about 2.4 times to about 25 times, about 2.4 times to about 24 times, about 2.4 times to about 23 times, about 2.4 times to about 22 times, about 2.4 times to about 21 times, about 2.4 times to about 20 times, about 2.4 times to about 19 times, about 2.4 times to about 18 times, about 2.4 times to about 17 times, about 2.4 times to about 16 times, about 2.4 times to about 15 times, about 2.5 times to about 25 times, about 3 times to about 25 times, about 4 times to about 25 times, about 5 times to about 25 times, about 6 times to about 25 times, about 7 times to about 25 times, about 8 times to about 25 times, about 9 times to about 25 times, or about 10 times to about 25 times wider (e.g., greater) than the area213A of the third opening213, but the present inventive concepts are not limited thereto.

The aforementioned biosensor10may be effectively applied to the various devices or things requiring a stretchability, for example, may be applied to (e.g., included in) an attachable device such as an wearable bioelectronics; a skin-like device; or a smart clothing to provide a biometric signal or a motion signal, or may be applied to things for monitoring a strain or the like to confirm the strain change in a real time. For example, the biosensor10may be applied to (e.g., included in) a patch-typed or band-typed attachable biometric device (e.g., the biosensor10may be a skin-attachable patch typed biosensor or a skin-attachable band typed biosensor), and the attachable biometric device may be attached to a region where is required to be treated and quantitatively measured for a motion of muscle or joint to provide the needed data for rehabilitation.

For example, the above biosensor10may be applied in an array arranged along with a raw and/or a column.

FIG.7Ais a schematic view illustrating an example of a biosensor array including a biosensor according to some example embodiments.

Referring toFIG.7A, the biosensor array10A according to some example embodiments includes a plurality of biosensors10. The plurality of biosensors10is exemplified as being arranged along with a row and a column, but is not limited thereto, and may be arranged in the various ways.

For example, when the attachable biometric device including the biosensor array10A is attached to a body area required for the treatment, it may accomplish to provide a healthcare device minimizing errors occurred depending on an attached position.

For example, the attachable biometric device including the biosensor array10A may be attached to an area required for the treatment, and the position where strain stress occurs may be effectively detected from the muscle or joint motions to effectively provide data for rehabilitation.

FIG.7Bis a schematic view of an electronic device according to some example embodiments.

Referring toFIG.7B, an electronic device1000(also referred to herein as a “device”) may include a processor1020, a memory1030, and a sensor1040that are electrically coupled together via a bus1010. The sensor1040may be any of the sensors according to any of the example embodiments (e.g., any example embodiments of biosensor10and/or biosensor array10A as described herein with reference toFIGS.1-6and7A). An electronic device1000including any of the sensors according to any of the example embodiments may be any of the attachable devices and/or stretchable devices according to any of the example embodiments, including for example an attachable biometric device as described according to any of the example embodiments. The memory1030, which may be a non-transitory computer readable medium, may store a program of instructions. The processor1020may execute the stored program of instructions to perform one or more functions. For example, the processor1020may be configured to process electrical signals generated by the sensor1040. The processor1020may be configured to generate an output (e.g., an image to be displayed on a display interface) based on such as processing.

In some example embodiments, some or all of the devices and/or elements thereof as described herein with reference to any of the drawings (including without limitation the elements of the electronic device1000) may include, may be included in, and/or may be implemented by one or more instances of processing circuitry such as hardware including logic circuits; a hardware/software combination such as a processor executing software; or a combination thereof. For example, the processing circuitry more specifically may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), an application processor (AP), a microcomputer, a field programmable gate array (FPGA), and programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), a neural network processing unit (NPU), an Electronic Control Unit (ECU), and the like. In some example embodiments, the processing circuitry may include a non-transitory computer readable storage device, for example a solid state drive (SSD), storing a program of instructions, and a processor (e.g., CPU) configured to execute the program of instructions to implement the functionality of any of the elements of the devices and/or elements thereof as described herein (including without limitation some or all of the electronic device1000shown inFIG.7B).

FIG.8is a schematic view illustrating an example of an operation of a biosensor device according to some example embodiments.

Referring toFIG.8, the biosensor10includes a photoelectric conversion layer500, a first light emitting layer610, and a pixel defining layer200. The biosensor10may detect pressure by a resistance change of a pressure sensor at a point of generating a particular (or, alternatively, predetermined) pressure such as a blood pressure, and the first light emitting layer610may be configured to emit light for detecting a biometric signal. Light may be reflected by a biometric (e.g., skin1100, blood vessel900), and the reflected light is received by a photoelectric conversion layer500to convert to an electrical signal. In some example embodiments, as a plurality of photoelectric conversion layers500adjacently disposed to each other may obtain different values depending upon a distance, the electrical signal may be treated by the various methods to enhance an accuracy of the sensor. The electrical signal converted from the reflected light may include biometric information. The electrical signal including the biometric information may be transferred to a sensor IC (not shown) or a processor (not shown).

Hereinafter, some example embodiments are illustrated in more detail with reference to examples. However, the present scope of the inventive concepts are not limited to these examples.

Evaluation of Strain Stress

The biosensors shown inFIGS.1and2are designed, and a strain stress to the photo-detecting element depending upon an area ratio of the pixel defining layer and the opening on the stretchable substrate is evaluated using a MATLAB software.

A stacked structure of the photo-detecting element is formed with IZO/organic photoelectric conversion layer/Al/encapsulation layer, and the area of the photo-detecting element is set to about 0.25 mm2(0.5 mm×0.5 mm).

The results are shown in Table 1.

TABLE 1Area of pixel defining layer/Strain stressArea of opening(unit: %)1.20.8120.602.40.530.3240.26

Referring to Table 1, the strain stress of the photo-detecting element is changed depending upon an area ratio of the pixel defining layer and the opening, and it may be expected that deformation of the element due to the strain stress may be reduced or prevented when the area of the pixel defining layer is about twice or more the area of the opening.

Manufacture of Biosensor

Example 1

A SEBS polymer is coated on a glass substrate and dried to provide a stretchable substrate. A metal wire which is used as an electric transferring path is formed on the stretchable substrate. Then indium zinc oxide (IZO) is sputtered on the stretchable substrate at a room temperature to provide electrodes. Subsequently, a photosensitive polymer of GXR601 is coated on the electrodes and the stretchable substrate to form a pixel defining layer, and then the pixel defining layer is patterned through a fine pattering process to form a first pixel defining layer having a first opening and a second pixel defining layer having a second opening.

In some example embodiments, each area of the first and the second pixel defining layers is 1 mm2, and each area of the first and the second opening is 0.25 mm2.

A lower electrode (IZO)/a hole auxiliary layer/an organic light emitting layer/an electron auxiliary layer/a upper electrode (Al) are sequentially stacked on the stretchable substrate to provide a red light emitting element (area: 0.5×0.5 mm2), and a lower electrode (IZO)/a hole auxiliary layer/a light absorbing layer (SubNc/C60)/an electron auxiliary layer/an upper electrode (Al) are sequentially stacked to provide a photo-detecting element (area: 0.5×0.5 mm2). Subsequently, a fluoro-based polymer and aluminum oxide (AlOx) are sequentially coated on the red light emitting element and the photo-detecting element to form an organic-inorganic hybrid bilayer-type encapsulant, manufacturing a biosensor according to Example 1.

Comparative Example 1

A biosensor is manufactured in accordance with the same procedure as in Example 1, except that each area of the first pixel defining layer and the second pixel defining layer of the biosensor is formed in 0.325 mm2.

Evaluation 1: Measurement of Photoelectric Conversion Efficiency and Dark Current Density

After measuring an external quantum efficiency (EQE) and a dark current density of the biosensors according to Example 1 and Comparative Example 1, the biosensors according to Example 1 and Comparative Example 1 are immersed in water for about 4 hours to about 5 hours and taken out therefrom, the biosensor (the stretchable substrate of the biosensor) is separated from the glass substrate, and then an external quantum efficiency (EQE) and the dark current density of the biosensors are measured in order to confirm the change of the external quantum efficiency (EQE) and the dark current density.

The external quantum efficiency (EQE) is evaluated at a wavelength of 650 nm according to an Incident Photon to Current Efficiency (IPCE) method.

The dark current density is evaluated from a dark current density in which a dark current measured using a current-voltage evaluating equipment (Keithley K4200 parameter analyzer) is divided by a unit pixel area. The dark current density is evaluated from a flowing current when a −2V to 2V bias is applied.

The results are shown inFIGS.9A,9B,10A, and10B.

FIG.9Ais a graph showing the external quantum efficiency (EQE) according to the wavelength of the biosensor according to Example 1,FIG.9Bis a graph showing the external quantum efficiency (EQE) according to the wavelength of the biosensor according to Comparative Example 1,FIG.10Ais a graph showing the dark current density according to the applied voltage before and after peeling of the stretchable substrate of the biosensor according to Example 1, andFIG.10Bis a graph showing the dark current density according to the applied voltage before and after peeling of the stretchable substrate of the biosensor according to Comparative Example 1.

Referring toFIGS.9A and10A, the external quantum efficiency (EQE) and the dark current density of the photo-detecting element of the biosensor according to Example 1 are not substantially changed before and after peeling process.

On the other hand, referring toFIGS.9B and10B, the external quantum efficiency (EQE) of the photo-detecting element of the biosensor according to Comparative Example 1 is significantly changed before and after peeling process, and particularly, the value is greatly decreased to a level of 20% relative to the value before peeling process at a wavelength of around 650 nm, and the change of the dark current density of the photo-detecting element before and after peeling process is also large.

Evaluation 2: SNR Measurement

The biosensors according to Example 1 and Comparative Example 1 are attached to a region near to a radial artery of the wrist and measured for a signal to noise ratio (SNR), and then the biosensors according to Example 1 and Comparative Example 1 are immersed in water for about 4 hours to 5 hours and taken out to separate the stretchable substrate from the glass substrate, and then attached to the region near to the radial artery of the wrist and measured for the signal to noise ratio (SNR) of the biosensors to confirm the change of the signal to noise ratio.

SNR signal data is collected using an AFE software.

The results are shown inFIGS.11A and11B.

FIG.11Ais a graph showing a biosignal before and after the peeling process of the biosensor according to Example 1 andFIG.11Bis a graph showing a biosignal before and after the peeling process of the biosensor according to Comparative Example 1.

Referring toFIG.11A, the biosensor according to Example 1 has substantially no change in the SNR value before and after the peeling process, and thus the performance of the photo-detecting element before and after peeling process is well maintained.

On the other hand, referring toFIG.11B, the biosensor according to Comparative Example 1 exhibits SNR values of 18.8 dB and 6.8 dB before and after the peeling process, respectively, which indicates that it has been greatly deteriorated after the peeling process.

From these results, the strain stress of the element after the peeling process by the wet process is varied depending upon a relative area of the pixel defining layer, and the performance degradation of the element does not occur in the biosensor according to Example 1 having a relatively wider (e.g., relatively greater) area of the pixel defining layer than the biosensor according to Comparative Example 1 having a relatively smaller area of the pixel defining layer.

While the inventive concepts have been described in connection with what is presently considered to be practical example embodiments, it is to be understood that the inventive concepts are not limited to these example embodiments. On the contrary, the inventive concepts are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.