WO2013066854A1

WO2013066854A1 - Peel initiating adhesive systems and methods

Info

Publication number: WO2013066854A1
Application number: PCT/US2012/062551
Authority: WO
Inventors: Vincent Michael DIPALMA
Original assignee: Abbott Diabetes Care Inc.
Priority date: 2011-10-31
Filing date: 2012-10-30
Publication date: 2013-05-10

Abstract

Provided are multi-sided adhesive systems and methods of using multi-sided adhesive systems, e.g., in medical device applications such as analyte monitoring. Embodiments include systems that have a first high tack side separated by a second low tack side with a substrate, and at least one peel initiating point about at least a portion of a perimeter of the systems that starts the peeling process of the low tack side at the peel initiating point(s) prior to the peeling of the other portions of the low tack side.

Description

PEEL INITIATING ADHESIVE SYSTEMS AND METHODS

PRIORITY

[0001] The present application claims priority to U.S. provisional application no.

61/553,936 filed October 31, 2011, entitled "Peel Initiating Adhesive Systems and Methods", the disclosure of which is incorporated herein by reference for all purposes.

BACKGROUND

[0002] Double sided adhesives are designed to adhere to an object at a first side and an object at a second side. In certain situations, however, the adherence requirements at the two sides may differ. For example, there may be a need to bond an object more tightly at a first side than at a second, and/or the temporal aspects may differ or require precise timing.

[0003] Merely increasing the peel strength of an adhesive at one or both sides of a multi- sided adhesive system will not necessarily meet all the requirements of certain systems. For example, systems may require a plurality of adhesive surfaces to have the same bonding requirement for certain applications, but may require the plurality of adhesive surfaces to have different bonding requirements for other applications.

[0004] Accordingly, as multi-sided adhesive systems continue to be used for a variety of applications, there continues to be interest in adhesive systems that meet the requirements of complex applications such as medical applications.

INCORPORATION BY REFERENCE

[0005] Patents, applications and/or publications described herein, including the following patents, applications and/or publications are incorporated herein by reference for all purposes: U.S. Patent Nos. 4,545,382, 4,711,245, 5,262,035, 5,262,305, 5,264,104, 5,320,715, 5,356,786, 5,509,410, 5,543,326, 5,593,852, 5,601,435, 5,628,890, 5,820,551, 5,822,715, 5,899,855, 5,918,603, 6,071,391, 6,103,033, 6,120,676, 6,121,009, 6,134,461, 6,143,164, 6,144,837, 6,161,095, 6,175,752, 6,270,455, 6,284,478, 6,299,757, 6,338,790, 6,377,894, 6,461,496, 6,503,381, 6,514,460, 6,514,718, 6,540,891, 6,560,471, 6,579,690, 6,591,125, 6,592,745, 6,600,997, 6,605,200, 6,605,201, 6,616,819, 6,618,934, 6,650,471, 6,654,625, 6,676,816, 6,730,200, 6,736,957, 6,746,582, 6,749,740, 6,764,581, 6,773,671, 6,881,551, 6,893,545, 6,932,892, 6,932,894, 6,942,518, 7,041,468, 7,167,818, 7,299,082,

-1- and 7,866,026, U.S. Patent Publication Nos. 2004/0186365, 2005/0182306, 2006/0025662, 2006/0091006, 2007/0056858, 2007/0068807, 2007/0095661,

2007/0108048, 2007/0199818, 2007/0227911, 2007/0233013, 2008/0066305,

2008/0081977, 2008/0102441, 2008/0148873, 2008/0161666, 2008/0267823,

2009/0054748, 2009/0294277, 2010/0213057, 2010/0081909, 2009/0247857,

2011/0106126, 2011/0082484, 2010/0326842, 2010/0198034, 2010/0324392,

2010/0230285, 2010/0313105, 2011/0213225, 2011/0021889, 2011/0193704,

2011/0190603, and 2011/0191044, U.S. Patent Application Nos. 13/071,461, 13/071,487, and 13/071,497, and U.S. Provisional Application No. 61/325,260.

SUMMARY

[0006] Provided are multi-sided adhesive systems and methods of using multi-sided

adhesive systems, e.g., in medical device applications such as analyte monitoring.

Embodiments include systems that have a first high tack side separated by a second low tack side with a substrate, and at least one peel initiating point about at least a portion of a perimeter of the systems that starts the peeling process of the low tack side at the peel initiating point(s) prior to the peeling of the other portions of the low tack side.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 shows an exploded view of an exemplary embodiment of a medical device delivery system that includes a peel initiating system according to the present disclosure;

[0008] FIG. 2 shows a cross sectional view of the exemplary embodiment of FIG. 1;

[0009] FIG. 3 shows a magnified view of area B of FIG. 2;

[0010] FIG. 4 shows a cross sectional view of certain embodiments of the peel initiating applicator adhesive of FIG. 1;

[0011] FIG. 5 shows a plan view of the peel initiating applicator adhesive of FIG. 1;

[0012] FIGS. 6A-6C show exemplary embodiments of peel initiating adhesives according to the present disclosure;

[0013] FIGS. 7A-7C show exemplary embodiments of peel initiating adhesives according to the present disclosure;

[0014] FIGS. 8A-8C show exemplary embodiments of peel initiating adhesives according to the present disclosure;

[0015] FIGS. 9A-9C show exemplary embodiments of peel initiating adhesives according to the present disclosure; and

-2- [0016] FIGS. 10A-10D show exemplary embodiments of peel initiating adhesives according to the present disclosure.

DETAILED DESCRIPTION

[0017] Before the present disclosure is further described, it is to be understood that this disclosure is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims.

[0018] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure.

[0019] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0020] 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. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, exemplary methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

[0021] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as "solely,"

-3- "only" and the like in connection with the recitation of claim elements, or use of a "negative" limitation.

[0022] The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present disclosure is not entitled to antedate such publication by virtue of prior disclosure. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.

[0023] Embodiments of the present disclosure include multi-sided adhesive systems for adhering an object to a first side of the system and an object to a second side of the system, where the adhesion and/or removal of the objects at and/or from the different sides may require different adhesive properties or requirements, e.g., adhesive strengths. The embodiments described herein find use in a variety of applications where adhesion to multiple sides of an adhesive system is needed, including medical applications. For example, embodiments may be configured to adhere a medical device to a skin surface on one side, and to another object such as an applicator on another side, at the same or different times. Embodiments include medical device applicator systems that include a medical device and an applicator to apply the medical device to the body of a user, and thereafter remove the applicator from the applied medical device while leaving the medical device on and/or in the body of a user.

[0024] In certain embodiments, systems include an on-body unit and an applicator.

Referring to FIGS. 1-3 which show an exploded view, cross sectional view, and an enlarged partial view, respectively, of an exemplary embodiment of a peel initiating medical device system 10 according to an embodiment of the present disclosure. Medical device system 10, in certain embodiments, includes an on-body unit 15, which may include a device 20 and a patch 30 that holds the device 20 to the body of a user, and a transfer adhesive 40 that holds the device 20 to the patch 30, and an applicator 200. In certain embodiments, device 20 may include a puck shaped device, sized and shaped for comfortable and unobtrusive adherence to the body of a user and configured for sensing and/or processing medical data, such as analyte, such as glucose, data. Examples of such devices can be found in, among others, U.S. Publication Nos. 2010/0198034 and

2011/0213225, the disclosures of each of which are incorporated herein by reference for all purposes. In certain embodiments, patch 30 can be flexible so that it conforms to the shape of the user's body. Device 20 may include (e.g., integrated therewith as a single unit) or be combinable with one or more of a housing, an electronics unit 22 or at least

-4- one processing unit or processor, a memory or data storage unit for storing instructions and/or data, an in vivo sensor 24 for analyte (e.g., glucose monitoring) sensing in vivo, a transmitter for communicating with a receiver and for transmitting analyte data and for sending or receiving instructions from the receiver or another device, a sensor support 26, and a potting material (e.g., a solid potting material) to encapsulate the electronics (not shown). An applicator 200 may include one or more of a housing 210, a protective, detachable cover 212, a pusher 214, a needle 216 to assist sensor delivery, and at least one spring 218 (e.g., an advance and/or return spring). The applicator may be a manual applicator, semi-manual applicator, automatic applicator, or semi-automatic applicator. For example, it may include one or more springs, or may omit springs in the completely manual configurations. Exemplary applicators can be found in, among others, U.S.

Publication No. 2011/0324392 and U.S. Application Nos. 13/071,461, 13/071,487 and 13/071,497, the disclosures of each of which are incorporated herein by reference for all purposes.

[0025] In certain embodiments, applicator housing 210 is configured to hold on-body unit 15, which may include patch 30, transfer adhesive 40 and device 20, with an adhesive bond. An applicator adhesive 100 is placed on a distal portion of housing 210, e.g., distal rim 220 of housing 210. Applicator adhesive 100 is designed to adhere to on-body patch 30 and secure it to applicator 200. This adhesive bond holds on-body unit 15 in place during transportation and handling of medical device system 10 before placing the on- body unit 15 on the skin. In certain embodiments, another adhesive, not shown, may be included to adhere applicator 200 to protective cover 212. This adhesive may have different adhesive properties, such as tackiness, than applicator adhesive 100, transfer adhesive 40 and/or patch adhesive 32'. In some embodiments, on-body unit 15 and applicator 200 or medical device system 10 are preassembled at the factory and shipped as a single unit.

[0026] To insert in vivo sensor 24 that is attached to on-body unit 15, in certain

embodiments, patch 30 is applied to the skin. The bottom or first surface 32 of patch 30 has adhesive 32' to secure it to the skin when contacted therewith. The adhesive 32' is biocompatible so that skin irritation is reduced. In some embodiments, adhesive 32' is covered with a peelable covering or backing material. The peelable covering or backing material can be removed from adhesive 32' before patch 30 is applied to the skin. Upon insertion of analyte sensor 24, pressure from applicator 200 may be used to ensure adhesive patch 30 is securely attached to the skin. Once sensor 24 is inserted using

-5- applicator 200, applicator 200 and applicator adhesive 100 are removed from the installed on-body unit 15. The adhesive force between adhesive 32' and the skin is greater than the adhesive force between adhesive 100 and on-body unit 15, which allows the user to apply an upwards force on applicator 200 to remove applicator 200 and adhesive 100 while leaving on-body unit 15, including inserted sensor 24, adhered to the skin. The adhesive force between adhesive 100 and applicator 200 is greater than the adhesive force between adhesive 100 and on-body unit 15. This allows adhesive 100 to be removed with applicator 200 when applicator 200 is removed from on-body unit 15. The adhesive force between two parts can be varied using a variety of means, such as, for example, using different adhesives with different tackiness or stickiness, varying the surface area covered by the adhesive, and by including peel initiating points or areas, as further described below, that are designed to initiate the peeling process and thus vary the associated adhesive force. In some embodiments, the adhesive force between the adhesive 32' and the skin is at least 10%, 20%, 30%, 40%, 50%, 75%, 100% or 200% greater that the adhesive force between the adhesive 100 and the on-body unit 15. In some embodiments, the adhesive force between the adhesive 100 and the applicator 200 is at least 10%>, 20%>, 30%, 40%, 50%, 75%, 100% or 200% greater that the adhesive force between the adhesive 100 and the on-body unit 15. Other adhesive force ratios between the adhesives and the skin and/or the applicator and/or the on-body unit may be applied.

7] FIG. 4 shows a cross sectional view of certain embodiments of applicator adhesive 100 of FIG. 1. Applicator adhesive 100 may include three layers: (1) a hi-tack adhesive 102 forming a first surface of applicator adhesive 100, e.g., the surface of applicator adhesive 100 that faces and is attached to applicator 200 (i.e., the applicator side), (2) an internal carrier 104, and (3) a low-tack adhesive 106 forming a second surface of applicator adhesive 100, e.g., the surface of applicator adhesive 100 that faces patch 30 (i.e., the patch side). The first and second sides may be opposite each other as in the embodiment of FIG. 4. In certain conventional systems, when the low tack adhesive is made strong enough to properly hold onto the patch during times when such adhesion is necessary, such as during shipping, storing, etc., the force required to detach the patch from the low tack side of the applicator adhesive when it is time to do so unintentionally detaches the high-tack adhesive from the applicator when the applicator and applicator adhesive are being removed from the patch after it has been installed to the body, instead of removing the applicator and applicator adhesive together at the same time.

-6- [0028] In order to ensure that applicator adhesive 100 is removed from the on-body unit 15, and further that it does not remove installed on-body unit 15 from its applied skin location upon its removal, during removal of applicator 200 from installed on-body unit 15, the applicator adhesives described herein reduce the force required to pull a low tack side of applicator adhesive 100 off of an attached device, which leaves applicator adhesive 100 attached to applicator 200 during the application of the pulling force.

Accordingly, the applicator adhesives described herein include at least one peel initiating point or area or protrusion. In certain embodiments, a peel initiating point or area is an area of an applicator adhesive about at least a portion of a perimeter of the applicator adhesive that is designed to start or initiate the peeling process of the low tack side at the peel initiating point(s) prior to starting the peeling process of the other portions of the low tack side. A peel initiating point may be a stress concentration area that concentrates stress forces to a certain location of an applicator adhesive.

[0029] A peel initiating point may be, for example, a dimple, a scallop, a projection, a protrusion, an angled section, or a pointed section. In certain embodiments, a peel initiating point includes at least one scallop positioned at least about a portion of at least one perimeter edge of an applicator adhesive. In certain embodiments, the apex or outwardly projecting area of the scallop is designed as a stress concentrating, peel initiating point. The one or more peel initiating points will be further described primarily as scallops, where such description is in no way intended to limit the scope of the disclosure. It is to be understood that a variety of peel initiating points are contemplated.

[0030] Accordingly, an applicator adhesive, such as applicator adhesive 100, may include a scalloped edge about at least a portion of an edge of the adhesive patch. An applicator adhesive may include an inner opening, e.g., sized to completely or partially

accommodate a device, such as device 20, therein, and therefore such embodiments may include both an inner perimeter edge and an outer perimeter edge. In many embodiments, the plurality of peel initiating apexes formed by a scalloped edge is positioned about the entire inner perimeter edge and/or the outer inner perimeter edge. A scalloped edge of a given applicator adhesive can be straight or curved in nature, or may include both straight and curved scallops. An applicator adhesive may include large scallops, medium sized scallops, small scallops, or a combination of a variety of sized and shaped scallops. The scallops may be positioned on an inside edge, an outside edge, or both. The peak or apex of a scallop may be at the largest radius of a patch or in board of the largest radius, i.e., the scallops may be formed as convex or concave scallops, whereby the peel initiating

-7- points may be peaks formed at the connection points of convex scallops at the largest radius of the patch, or the peel initiating points may be points formed at the connection points of concave scallops within the radius of the patch. The scallops may cover an entire edge or any portion of an edge. A given edge may include one type or a mix of different types of scallops, where the mix may differ in one or more features (size and/or shape and/or pattern), and another edge may include another type or another mix.

Various exemplary scallop embodiments of peel initiating adhesives are shown in FIGS. 6A-6C, 7A-7C, 8A-8C, 9A-9C and 10A-10D, further described below.

[0031] Referring back to FIGS. 1-3, during removal of applicator 200, the applicator can be peeled off or pulled straight off of on-body unit 15. If applicator 200 is peeled off, it may be peeled off in any direction in embodiments where a plurality of peel initiating points are positioned regularly around the entire outer and/or inner perimeter edge of the adhesive. In embodiments where a single peel initiating point is used or a plurality of peel initiating points are positioned preferentially at particular locations along the outer and/or inner perimeter edge of the adhesive, applicator 200 is preferentially peeled off by applying a force to the applicator 200 in a direction that concentrates the force to at least one of the peel initiating points. For an exemplary circular or oval or other analogous shaped device 20 and patch 30 such as the embodiment of FIG. 1, scallops 120 of applicator adhesive 100 are applied to the full 360 degrees of the applicator adhesive outer edge. When a peeling force is applied (e.g., by a user) to applicator 200, a force is distributed to the face of applicator adhesive 100. The force is highest at the outside edge, and the scallops on the outside edge concentrate the force over a smaller edge than if the scallops were not there. This causes applicator adhesive 100 to release patch 30 at these peel initiating points of each scallop first, and enables the rest of applicator adhesive 100 to peel away from patch 30 without becoming dislodged from applicator 200.

Accordingly, the peel initiating areas of the scalloped edge initiate the peeling of the applicator adhesive.

[0032] If applicator 200 is pulled straight off, the forces are also distributed on the entire face of applicator adhesive 100. This causes the skin to which it is applied to pull on device 20. Since the adhesive patch is securely attached to the skin, the skin under device 20 pulls on adhesive patch 30 and creates a higher stress concentration along the inner edge of the applicator adhesive. Scallops on the inside edge (see, for example, FIGS. 8A- 8C & 9A-9C) concentrate the force over a much smaller edge than if the scallops were not there. This causes applicator adhesive 100 to release patch 30 at these peel initiating

-8- points of each scallop first, and enables the rest of applicator adhesive 100 to peel away from patch 30. Accordingly, the peel initiating areas of the scalloped edge initiate the peeling of the applicator adhesive.

[0033] FIG. 5 shows an enlarged view of applicator adhesive 100 of FIG. 1. As can be seen in the figure, applicator adhesive 100 has a first adhesive side 102 and a second adhesive side 106, wherein in certain embodiments, the two adhesive sides are opposite each other and separated by intermediate layer 104 so that the two sides sandwich intermediate layer 104, such as shown in FIG. 4. Applicator adhesive 100 includes outer edge 126, and in certain embodiments, also includes an inner opening 118 and an inner edge 124. As such, edges 124, 126 provide outer and inner applicator adhesive perimeters.

[0034] The different sides 102,106 of the system may include the same or different

adhesives that can differ in at least one parameter. If different adhesives are used, the adhesive properties of the different adhesives may be the same or different. In certain embodiments, side 102 is a high tack side and side 106 is a low tack side, where high and low are relative terms with respect to relative tack strength of each side with respect to the other. As such, one side, such as side 102, may have a higher tack strength than another side, such as side 106. In certain embodiments, one side may have a tack strength of about 30oz/in to about 60 oz/in, and another side may have a tack strength that is less. The tack strengths of the sides may vary from each other by about 1% or less to about 100% or more relative to one another. While exemplary tack strengths are given above, it is to be understood that any suitable tack strength may be employed for the adhesives.

[0035] In the embodiment of FIG. 5, the peel initiating area is limited to outer perimeter edge 126, and surrounds the entire perimeter of the applicator adhesive 100. The peel initiating points in this embodiment are in the form of outwardly projecting protrusions 130a, 130b, 130c,... disposed along outer edge 126, which is scalloped in this

embodiment in a manner to provide adjacent peaks about at least a portion of the edge, and troughs 140a, 140b, 140c, ...between immediately adjacent peaks. The peaks 130a, 130b, 130c,... may be pointed or rounded, or a combination of pointed and rounded. In certain embodiments, the protrusions are disposed about the entire outer edge of the system, and each may terminate in sharp points.

[0036] The distance L between protrusions, if there is more than one, may be uniform or may be non uniform. In certain embodiments, a pattern of uniform distances and/or non uniform distances may be repeated one or more times about the perimeter. If there is

-9- greater than two protrusions, then the distance between every pair of protrusions may be the same, or it may differ such that the distance between a first pair of protrusions may differ from the distance between at least a second pair of protrusions about the edge. In many embodiments, the distance L between protrusions is determinate upon the size of the applicator adhesive and the number of scallops of the applicator adhesive. In the embodiment shown in FIG. 5, the applicator adhesive 100 has an outer diameter of approximately 35mm and the distance L between protrusions is in a range from about 5mm to about 7mm.

[0037] The depth D of a trough, defined by the most shallow trough point to the top of a trough peak, may be uniform or may be non uniform. In certain embodiments, a pattern of uniform trough depths and/or non uniform trough depths may be repeated one or more times about the perimeter. If there is greater than two protrusions, then the trough depth between every pair of protrusions may be the same, or it may differ such that the trough depth between a first pair of protrusions may differ from the trough depth between at least a second pair of protrusions about the edge. In many embodiments, trough depth is determinate upon the size of the applicator adhesive and the number of scallops of the applicator adhesive. In the embodiment shown in FIG. 5, the applicator adhesive 100 has a trough depth D of approximately 3.5mm. In certain embodiments, troughs may have gentle sloping sides, may have stepped sides, or may have steeply angled sides, and may be shaped in a manner of a "U" or a "V" shape. The widths Wl and W2 of an applicator adhesive may vary according to application. In certain embodiments, the outer diameter of an applicator adhesive may range from about 15mm to about 130mm and the inner diameter may range from about 10mm to about 100mm. The widths, Wl and W2 may range from about 5mm to about 30mm and the ratio of widths Wl to W2 may be from about 1 :1 up to about 5: 1. The scallop length L may range from about 1 % of the circumference of the applicator adhesive to about 50% of the circumference of the applicator adhesive.

[0038] The surface area of an applicator adhesive may vary depending on a variety of factors including the dimensions and weight of a corresponding device. In certain embodiments, the surface area ranges from about 25mm² to about 2,500mm², e.g., from about 150mm² to about 350mm².

[0039] The number of peel initiators, or scallops as in the embodiment of FIG. 1, may vary, e.g., depending on the size of the applicator adhesive. In certain embodiments, the number may range from 1 to about 100 or even more, e.g., from about 2 to about 50, e.g.,

-10- from about 4 to about 25, e.g., about 19. For example, an applicator adhesive having a circular shape may have a surface area of about 300mm², and may have 19 protrusions. An applicator adhesive having a circular shape may have an outer perimeter of about 150mm, and may have 19 protrusions.

[0040] Referring back to FIG. 5, for the particular embodiment shown, the applicator adhesive 100 may have an outer diameter of 35mm and an inner diameter of 28mm. The width Wl from the inner perimeter to the scallop apex is approximately 3.5mm and the width W2 from the inner perimeter to the scallop trough is approximately 2mm. The embodiment of FIG. 5 includes 18 scallops, the length L of each scallop approximately 6mm and the depth D of each scallop approximately 1.5mm. The surface area is approximately 234mm². While particular dimensions are indicated above with respect to the embodiment of FIG. 5, as set forth above, it is understood that the dimensions could be any distance in an acceptable range for the device to be adhered to the skin.

[0041] FIGS. 6A-6C show exemplary applicator adhesive embodiments having a circular shape, and inner hole, and inner and outer perimeters, and a plurality of pointed peel initiating protrusions about the entire outer perimeters providing scalloped patterns. As shown, each of FIGS. 6A-6C has different numbers of peel initiating protrusions.

[0042] FIGS. 7A-7C show exemplary applicator adhesive embodiments having a circular shape, and inner hole, and inner and outer perimeters, and a plurality of rounded peel initiating protrusions about the entire outer perimeters providing scalloped patterns. As shown, each of FIGS. 7A-7C has different numbers of peel initiating protrusions.

[0043] FIGS. 8A-8C show exemplary applicator adhesive embodiments having a circular shape, and inner hole, and inner and outer perimeters, and a plurality of rounded peel initiating protrusions about the entire inner perimeters providing scalloped patterns. As shown, each of FIGS. 8A-8C has different numbers of peel initiating protrusions.

[0044] FIGS. 9A-9C show exemplary applicator adhesive embodiments having a circular shape, and inner hole, and inner and outer perimeters, and a plurality of pointed peel initiating protrusions about the entire inner perimeters providing scalloped patterns. As shown, each of FIGS. 9A-9C has different numbers of peel initiating protrusions.

[0045] Other applicator adhesive embodiments, shown in FIGS. 10A-10D, include peel initiating protrusions on both the inner and outer perimeters. In some embodiments, both the inner and outer perimeters have rounded peel initiating protrusions. In some embodiments, both the inner and outer perimeters have pointed peel initiating protrusions. In some embodiments, the inner perimeter has rounded peel initiating protrusions and the

-11- outer perimeter has pointed peel initiating protrusions. In some embodiments, the inner perimeter has pointed peel initiating protrusions and the outer perimeter has rounded peel initiating protrusions. In other embodiments, the inner perimeter and/or the outer perimeter can have a plurality of different types of peel initiating protrusions including the rounded peel initiating protrusions and the pointed peel initiating protrusions.

[0046] In some embodiments, an apparatus includes an applicator for applying an on- body unit to the skin of a user, the applicator comprising a proximal portion and a distal portion; and an applicator adhesive having a first surface and a second surface, wherein a first adhesive is disposed on the first surface of the applicator adhesive and a second adhesive is disposed on the second surface of the applicator adhesive, wherein the first surface of the applicator adhesive is reversibly attached to the distal portion of the applicator by the first adhesive, wherein the applicator adhesive includes at least one peel initiating protrusion configured to concentrate force at a distal end of the at least one peel initiating protrusion.

[0047] In some embodiments, the first adhesive has a higher adhesive strength than the second adhesive. In some embodiments, the at least one peel initiating protrusion is rounded. In some embodiments, the at least one peel initiating protrusion is pointed.

[0048] In some embodiments, the applicator adhesive has an outer perimeter and an inner perimeter forming an opening configured to receive the on-body unit. In some embodiments, the at least one peel initiating protrusion is located on the outer perimeter. In some embodiments, the at least one peel initiating protrusion is located on the inner perimeter.

[0049] In some embodiments, a system includes an on-body unit for measuring in vivo an analyte level in a user, the on-body unit comprising a housing disposed on a patch, the patch having a skin contact surface that is covered with a skin compatible adhesive; an applicator for applying the on-body unit to the skin of a user, the applicator comprising a proximal portion and a distal portion; and an applicator adhesive having a first surface and a second surface, wherein a first adhesive is disposed on the first surface of the applicator adhesive and a second adhesive is disposed on the second surface of the applicator adhesive, wherein the first surface of the applicator adhesive is reversibly attached to the distal portion of the applicator by the first adhesive, wherein the second surface of the applicator adhesive is reversibly attached to the on-body unit by the second adhesive, wherein the applicator adhesive includes at least one peel initiating protrusion configured to concentrate force at a distal end of the at least one peel initiating protrusion.

-12- [0050] In some embodiments, the first adhesive has a higher adhesive strength than the second adhesive. In some embodiments, the skin compatible adhesive has a higher adhesive strength than the second adhesive.

[0051] In some embodiments, the at least one peel initiating protrusion is rounded. In some embodiments, the at least one peel initiating protrusion is pointed.

[0052] In some embodiments, the applicator adhesive has an outer perimeter and an inner perimeter forming an opening configured to receive the on-body unit. In some embodiments, the at least one peel initiating protrusion is located on the outer perimeter.

In some embodiments, the at least one peel initiating protrusion is located on the inner perimeter.

[0053] In some embodiments, a method includes providing an on-body unit for

measuring in vivo an analyte level under a skin layer, the on-body unit comprising a housing disposed on a patch, the patch having a skin contact surface that is covered with a skin compatible adhesive; providing an applicator for applying the on-body unit to the skin layer, the applicator comprising a proximal portion and a distal portion; reversibly adhering a first surface of an applicator adhesive to the distal portion of the applicator using a first adhesive disposed on the first surface; reversibly adhering a second surface of the applicator adhesive to the on-body unit using a second adhesive disposed on the second surface; wherein the applicator adhesive includes at least one peel initiating protrusion configured to concentrate force at a distal end of the at least one peel initiating protrusion.

[0054] Various other modifications and alterations in the structure and method of

operation of the embodiments of the present disclosure will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. Although the present disclosure has been described in connection with certain embodiments, it should be understood that the present disclosure as claimed should not be unduly limited to such embodiments. It is intended that the following claims define the scope of the present disclosure and that structures and methods within the scope of these claims and their equivalents be covered thereby.

-13-

Claims

WHAT IS CLAIMED IS:

1. An apparatus, comprising:

an applicator for applying an on-body unit to the skin of a user, the applicator comprising a proximal portion and a distal portion; and

an applicator adhesive having a first surface and a second surface, wherein a first adhesive is disposed on the first surface of the applicator adhesive and a second adhesive is disposed on the second surface of the applicator adhesive, wherein the first surface of the applicator adhesive is reversibly attached to the distal portion of the applicator by the first adhesive, wherein the applicator adhesive includes at least one peel initiating protrusion configured to concentrate force at a distal end of the at least one peel initiating protrusion.

2. The apparatus of claim 1, wherein the first adhesive has a higher adhesive strength than the second adhesive.

3. The apparatus of claim 1, wherein the at least one peel initiating protrusion is rounded.

4. The apparatus of claim 1, wherein the at least one peel initiating protrusion is pointed.

5. The apparatus of claim 1, wherein the applicator adhesive has an outer perimeter and an inner perimeter forming an opening configured to receive the on-body unit.

6. The apparatus of claim 5, wherein the at least one peel initiating protrusion is located on the outer perimeter.

7. The apparatus of claim 5, wherein the at least one peel initiating protrusion is located on the inner perimeter.

8. A system, comprising:

an on-body unit for measuring in vivo an analyte level in a user, the on-body unit comprising a housing disposed on a patch, the patch having a skin contact surface that is covered with a skin compatible adhesive;

an applicator for applying the on-body unit to the skin of a user, the applicator comprising a proximal portion and a distal portion; and

-14- an applicator adhesive having a first surface and a second surface, wherein a first adhesive is disposed on the first surface of the applicator adhesive and a second adhesive is disposed on the second surface of the applicator adhesive, wherein the first surface of the applicator adhesive is reversibly attached to the distal portion of the applicator by the first adhesive, wherein the second surface of the applicator adhesive is reversibly attached to the on-body unit by the second adhesive, wherein the applicator adhesive includes at least one peel initiating protrusion configured to concentrate force at a distal end of the at least one peel initiating protrusion.

9. The system of claim 8, wherein the first adhesive has a higher adhesive strength than the second adhesive.

10. The system of claim 9, wherein the skin compatible adhesive has a higher adhesive strength than the second adhesive.

11. The system of claim 8, wherein the at least one peel initiating protrusion is rounded.

12. The system of claim 8, wherein the at least one peel initiating protrusion is pointed.

13. The system of claim 8, wherein the applicator adhesive has an outer perimeter and an inner perimeter forming an opening configured to receive the on-body unit.

14. The system of claim 13, wherein the at least one peel initiating protrusion is located on the outer perimeter.

15. The system of claim 13, wherein the at least one peel initiating protrusion is located on the inner perimeter.

16. A method, comprising :

providing an on-body unit for measuring in vivo an analyte level under a skin layer, the on-body unit comprising a housing disposed on a patch, the patch having a skin contact surface that is covered with a skin compatible adhesive;

providing an applicator for applying the on-body unit to the skin layer, the applicator comprising a proximal portion and a distal portion;

-15- reversibly adhering a first surface of an applicator adhesive to the distal portion of the applicator using a first adhesive disposed on the first surface;

reversibly adhering a second surface of the applicator adhesive to the on-body unit using a second adhesive disposed on the second surface;

wherein the applicator adhesive includes at least one peel initiating protrusion configured to concentrate force at a distal end of the at least one peel initiating protrusion.

17. The method of claim 16, wherein the first adhesive has a higher adhesive strength than the second adhesive.

18. The method of claim 17, wherein the skin compatible adhesive has a higher adhesive strength than the second adhesive.

19. The method of claim 16, wherein the at least one peel initiating protrusion is rounded.

20. The method of claim 16, wherein the at least one peel initiating protrusion is pointed.

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