1111111111111111 IIIIII IIIII 11111 1111111111 111111111111111 lllll lllll 111111111111111 11111111
`US 20080275327Al
`
`c19) United States
`c12) Patent Application Publication
`Faarbaek et al.
`
`c10) Pub. No.: US 2008/0275327 Al
`Nov. 6, 2008
`(43) Pub. Date:
`
`(54) THREE-DIMENSIONAL ADHESIVE DEVICE
`HAVING A MICROELECTRONIC SYSTEM
`EMBEDDED THEREIN
`
`(76)
`
`Inventors:
`
`Susanne Holm Faarbaek,
`Vaerloese (DK); Karsten Hoppe,
`Copenhagen O (DK); Peter Boman
`Samuelsen, Rungsted Kyst (DK);
`Jens Branebjerg, Hoersholm (DK)
`
`Correspondence Address:
`JACOBSON HOLMAN PLLC
`400 SEVENTH STREET N.W., SUITE 600
`WASHINGTON, DC 20004 (US)
`
`(21)
`
`Appl. No.:
`
`11/886,032
`
`(22)
`
`PCT Filed:
`
`Mar. 9, 2006
`
`(86)
`
`PCT No.:
`
`PCT/DK2006/050006
`
`§ 371 (c)(l),
`(2), ( 4) Date:
`
`Apr. 3, 2008
`
`(30)
`
`Foreign Application Priority Data
`
`Mar. 9, 2005
`Dec.9,2005
`
`(DK) ........................... PA 2005 00354
`(DK) ........................... PA 2005 01748
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`A61B 5104
`B32B 33/00
`B23P 17100
`B28B 3102
`(52) U.S. Cl. ....... .
`(57)
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`600/382; 428/40.1; 264/319; 29/592.1
`ABSTRACT
`
`Accordingly, the present invention relates to a three-dimen(cid:173)
`sional adhesive device to be attached to the body surface of a
`mammal comprising a microelectronic sensing system char(cid:173)
`acterized by
`(a) a three-dimensional adhesive body made of a pressure
`sensitive adhesive having an upper surface and a bottom
`surface;
`(b) a microelectronic system embedded in the body of the
`pressure sensitive adhesive;
`(c) one or more cover layer(s) attached to the upper surface;
`and
`( d) optionally a release liner releasable attached to the bottom
`surface of the adhesive device.
`Suitably the microelectronic system is a microelectronic
`sensing system capable of sensing physical input such as
`pressure, vibration, sound, electrical activity ( e.g. from
`muscle activity), tension, blood-flow, moisture, temperature,
`enzyme activity, bacteria, pH, blood sugar, conductivity,
`resistance, capacitance, inductance or other chemical, bio(cid:173)
`chemical, biological, mechanical or electrical properties.
`
`101
`
`103
`
`APPLE 1007
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`1
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`Patent Application Publication
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`Nov. 6, 2008 Sheet 1 of 7
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`Patent Application Publication
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`Nov. 6, 2008 Sheet 2 of 7
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`US 2008/0275327 Al
`
`Nov. 6, 2008
`
`1
`
`THREE-DIMENSIONAL ADHESIVE DEVICE
`HAVING A MICROELECTRONIC SYSTEM
`EMBEDDED THEREIN
`
`FIELD OF INVENTION
`
`[0001] The invention relates to micro electronic systems
`predominantly for monitoring physiological or neurological
`conditions. More particular the invention relates to invasive
`and non-invasive microelectronic systems embedded in a
`three-dimensional adhesive device, which may be attached to
`the surface, suitably the skin, of a mammal. The microelec(cid:173)
`tronic systems suitably utilises wireless communication and
`are useful for measuring ECG (Electro CardioGraphy ), EMG
`(Electro MyoGraphy), EEG (Electro EncephaloGraphy),
`blood glucose, pulse, blood pressure, pH, and oxygen.
`
`BACKGROUND
`
`[0002] The attachment of sensing systems to the skin by
`means of pressure sensitive adhesives is well established.
`Thus, AMBU A/S, DK has a number of products for measur(cid:173)
`ing ECG, which is attached to the skin by foam adhesives,
`micro-porous adhesives or hydro gel adhesives. These sensors
`are in general connected with wires to a monitoring device.
`[0003]
`In WO 03/065926 A2 Ozgus et al disclose a wear(cid:173)
`able biomonitorwith a flexible and thin integrated circuit. The
`patent application addresses a way to achieve high comfort of
`wear by using a thin layer adhesive or pads of adhesive for
`fixation to the skin. However, the adhesives used are occlud(cid:173)
`ing. The application further describes a sensor module for
`wireless data collection having a thin sheet of silicon com(cid:173)
`prising the circuit and a flexible power source being build into
`the sensor module as layers.
`[0004]
`In U.S. Pat. No. 5,054,488 Mus et al disclose an
`opto-electronic sensor for producing electrical signals repre(cid:173)
`sentative of a physiological condition. The sensors may be
`attached to the body by a double-sided pressure sensitive
`adhesive on a polyester lining.
`[0005]
`In U.S. Pat. No. 5,458,124 Stanko et al disclose
`electro-cardiographic-electrodes being attached to the body
`by double-sided pressure sensitive adhesive.
`[0006]
`In U.S. Pat. No. 6,372,951 Ter-Ovanesyan et al dis(cid:173)
`close a sensor operatively connected to a disposable article,
`fitted to the wearer by an adhesive patch. A wide variety of
`body adhering compositions may be used.
`[0007]
`In U.S. Pat. No. 6,385,473 Haines et al disclose a
`laminated sensor device attached to mammalian subject with
`two strips ofhydrocolloid adhesive. The laminated structure
`consists also ofhydrogel in contact with hydrocolloid adhe(cid:173)
`sive. The lifetime of the device is specified to 24 hrs.
`[0008]
`In WO 99/59465 Feierbach et al disclose an appa(cid:173)
`ratus for monitoring the physiological condition of a patient.
`The apparatus includes a patch having a distal side for being
`fixed to the patient. Also the apparatus may include an elec(cid:173)
`tronics housing that may be coupled with said patch. In one
`embodiment the surface of the apparatus may be pre-formed
`to the contours of a body part. The patch carrying the elec(cid:173)
`tronic housing may be soft and provide a natural feel and may
`be produced from latex, silicon or another rubberised fabric.
`The upper surface of the patch with the electronic housing
`may have a smooth convex shape as illustrated in FIG. 2B and
`FIG. 8 of the patent. The patch is coupled to the skin of the
`patient by an adhesive. Such adhesive may be a hydrocolloid
`skin protective adhesive manufactured by 3M. Hence the
`
`patent application teaches the use of a hydrocolloid adhesive
`liner for fixation of a sensor having a smooth and soft backing
`optionally in a pre-formed shape to fit a contour of the body.
`[0009]
`In US application 2003/0009097 Al Sheraton et al
`disclose a sensor having a hydrogel electric conducting cen(cid:173)
`tral skin contacting part and a hydrocolloid adhesive part
`surrounding this central part for adhesion of the sensor and on
`said combined disc a conductive terminal connected to a wire.
`This construct is further protected by laminate film layers
`adhered to the terminal and the outer rim of adhesive. The
`patent application teaches the use ofhydrocolloid adhesives
`for fixation of sensors to the skin and emphasizes the aspect of
`making very thin and flexible electrodes. The patent applica(cid:173)
`tion is peculiar in the sense that it combines the use ofhydro(cid:173)
`colloid adhesives and hydrogels. For any practical purpose
`the disclosed constructs will be useless as the moisture from
`the hydrogel will migrate into the hydrocolloid adhesive and
`disrupt this over time.
`[0010] Recent developments in devices for monitoring
`physiological conditions are wire-less types. Apart from
`being able to monitor a physiological condition invasively or
`non-invasively and potentially compare to a reference, they
`are be able to process data and transmit them to a portable
`device. In fact the attachable device may also function as an
`alarm itself, e.g. by use of e.g. light emission, audio alarm or
`another warning signal.
`[0011] When monitoring physiological or neurological
`conditions of the human body it is important that the attached
`microelectronic system is as comfortable to wear as possible,
`especially when the person carrying the device is not bedrid(cid:173)
`den and shows normal physical activity or even excess physi(cid:173)
`cal activity like in sport or in sports medicine. The user should
`preferably not feel the attached microelectronic system and
`the monitoring should preferably be kept in private. However,
`in this respect the known microelectronic systems suffer from
`several major drawbacks as described below.
`[0012] Attachment to the skin by means of occlusive pres(cid:173)
`sure sensitive adhesives often leads to skin irritation due to the
`occlusion of moisture and due to irritants, such as monomers
`from the pressure sensitive adhesive polymer system, e.g.
`from for instance acrylic adhesives. Irritation may be the in
`form of itching and erythema and may especially develop
`when the adhesive device is attached for a prolonged period of
`time. Occlusion may also increase the risk of creating allergy
`to the adhesive composition. One often used way to solve the
`negative effects of occlusion is to use micro porous tapes, but
`such tapes are essentially two-dimensional and thin and does
`not protect the microelectronic system from shear forces due
`to friction against clothes and the like.
`[0013]
`In the above references, the devices are attached to
`the skin by thin planar adhesive layers carrying the micro(cid:173)
`electronic system as a bulky part leading to discomfort of the
`patient or person carrying the device due to stiffness or fric(cid:173)
`tion against clothing and increasing the risk of involuntarily
`detachment from the skin. When such a device is to be used
`for a prolonged period of time, it is important to reduce any
`type of discomfort due to skin irritation or inconvenience of
`carrying a bulky device. Furthermore it is crucial for the
`signal detection that the adhesive device is kept fixed to the
`skin until it is deliberately removed.
`[0014] Proper adhesion of the device requires a fairly thick
`layer of the planar adhesive. However, a fairly thick layer may
`show a tendency of adhering at the edge to clothing or linen
`and by doing so a tendency to roll and detach is created.
`
`9
`
`

`

`US 2008/0275327 Al
`
`Nov. 6, 2008
`
`2
`
`[0015] Many sensors are connected to the monitoring sys(cid:173)
`tems with wires. The disadvantage of such a system is that the
`patient does not have freedom to move since the wires are
`attached to the sensors on the body and connected to a moni(cid:173)
`toring system. Whenever the patient wants to move he must
`be careful not to dislodge any of the wires attached to the
`sensors, and he must further pick up the monitoring system
`and carry it along.
`[0016] None of the above mentioned references describes a
`body sensor device consisting of an optionally hydrocolloid
`containing thermoplastic pressure sensitive adhesive and/or
`chemically curing pressure sensitive adhesive, moulded or
`cast into a three-dimensional adhesive body having a micro
`electronic system embedded therein as according to the
`present invention.
`[0017] The known sensors overcoming some of the above(cid:173)
`mentioned disadvantages are not as simple and inexpensive to
`manufacture with respect to the adhesive part of the device as
`the adhesive devices of the invention.
`[0018] The adhesive devices of the invention having a
`microelectronic system embedded therein may be produced
`relatively easily and besides a cover layer and optionally a
`release layer, without the need of any other layers in the
`device and is therefore commercially attractive.
`[0019] With an embedment of the micro electronic compo(cid:173)
`nents an improved protection against mechanical damage and
`penetration of moisture from the surrounding environment is
`also achieved.
`[0020] Furthermore, today many types of electronics are
`temporarily attached to different surfaces. Especially within
`medical care different types of medical devices such as
`probes and sensors are attached to different areas of the skin
`in order to, for example, detect different biomedical signals or
`retrieve samples from a patient. Often these medical devices
`are only attached for a limited period of time until a disease is
`diagnosed or a patient's health has improved. However, some
`chronic diseases may require periodical monitoring, for
`example while the patient is sleeping, or in some cases con(cid:173)
`stant monitoring is desired day and night. The medical device,
`which is attached to the skin of the patient, may be adapted to
`detect many types of signals, it could for example be a sensor
`for detecting one or more signals such as electromyographic
`(EMG) signals, electrocardiographic (ECG) signals and elec(cid:173)
`troencephalography (EEG) signals.
`[0021] Such medical devices may be broken up into at least
`three general elements, a microelectronic element for mea(cid:173)
`suring a desired value, such as for example a biosignal; an
`adhesive for attaching the microelectronic element to a sur(cid:173)
`face; and a power source for powering at least a part of the
`microelectronic circuit.
`[0022] The different elements have different lifespan, how(cid:173)
`ever, since the elements are typically assembled in one
`inseparable unit they are all disposed after use. When looking
`at the elements individually it may however be understood
`that they have different lifespan. Thus, the adhesive element
`typically has a one-time use only. The power source may in
`some cases be reused a few times depending on the applica(cid:173)
`tion and the size of the battery. However, the microelectronic
`element may be reused a large number of times thereby mak(cid:173)
`ing it an expensive element to dispose after one use only.
`[0023] Thus in order to improve the cost effectiveness of
`the medical device there exists a need to be able to reuse the
`element(s ), which are still operable after use.
`
`[0024] US 2002/0180605 discloses a method of monitoring
`a physiological characteristic. The method disclosed can
`include subsequent steps of removing adhesive pads from a
`sensor module and heating the sensor module in an autoclave
`for sterilization after data has been transferred from the sensor
`module to the receiver module.
`
`SUMMARY OF THE INVENTION
`
`[0025] Accordingly, the present invention relates to a three(cid:173)
`dimensional adhesive device comprising an microelectronic
`sensing system characterized by
`(a) a three-dimensional adhesive body made of a pressure
`sensitive adhesive having an upper surface and a bottom
`surface;
`(b) a microelectronic system embedded in the body of the
`pressure sensitive adhesive;
`(c) one or more cover layer(s) attached to the upper surface;
`and
`( d) optionally a release liner releasable attached to the bottom
`surface of the adhesive device.
`[0026] Suitably, the microelectronic system is a microelec(cid:173)
`tronic sensing system. The microelectronic sensing system is
`suitably capable of sensing physical input such as pressure,
`vibration, sound, electrical activity (e.g. from muscle activ(cid:173)
`ity), tension, blood-flow, moisture, temperature, enzyme
`activity, bacteria, pH, blood sugar, conductivity, resistance,
`capacitance, inductance or other chemical, biochemical, bio(cid:173)
`logical, mechanical or electrical input.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0027] FIG. 1 shows a die section of the shape of a typical
`representative of the adhesive device according to the inven(cid:173)
`tion. CT is the maximal thickness of the device and PT is the
`thickness in the periphery of the device.
`[0028] FIG. 2 illustrates a microelectronic system embed(cid:173)
`ded/integrated in a three-dimensional (3D) adhesive. The
`zoom-box indicates the part of the adhesive device illustrated
`in FIGS. 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12.
`[0029] FIG. 3 illustrates a microelectronic system (hatched
`box) that is completely integrated within the adhesive body.
`[0030] FIG. 4 illustrates that parts of the microelectronic
`system may be positioned in different locations integrated
`within the adhesive device with proper mechanical or electri(cid:173)
`cal interconnection between the parts.
`[0031] FIG. 5 illustrates a microelectronic system, which is
`applied into a recess in the adhesive body. The recess is distal
`to skin fixation area. The microelectronic system may option(cid:173)
`ally be exchangeable, or reusable.
`[0032] FIG. 6 illustrates the microelectronic system in
`which the upper part may be exchangeable or reusable and the
`lower part be permanently integrated in the adhesive body.
`[0033] FIG. 7 illustrates that parts of the microelectronic
`system may be situated in different locations within the adhe(cid:173)
`sive device with proper mechanical or electrical interconnec(cid:173)
`tion between the parts.
`[0034] FIG. 8 illustrates a microelectronic system, which is
`embedded/applied into a recess on the adhesive side of the
`adhesive body.
`[0035] FIG. 9 illustrates a device with a microelectronic
`system in which the lower part may be exchangeable or reus(cid:173)
`able and the upper part be permanently integrated in the
`adhesive body.
`
`10
`
`

`

`US 2008/0275327 Al
`
`Nov. 6, 2008
`
`3
`
`[0036] FIG. 10 illustrates a system with some microelec(cid:173)
`tronic components integrated within the adhesive body dur(cid:173)
`ing production (small hatched box) and some microelectronic
`components applied later thereby establishing the necessary
`mechanical/electrical connections.
`[0037] FIG. 11 illustrates a microelectronic system embed(cid:173)
`ded in the adhesive which system is applicable and accessable
`both from the distal side and the skin fixation side of the
`adhesive body.
`[0038] FIG. 12 illustrates a system where the microelec(cid:173)
`tronic system is assembled from two parts one of which, or
`each of which may be exchangeable or reusable.
`[0039]
`In all the above constructs of the invention the upper
`surface remains smooth irrespective the presence of compo(cid:173)
`nents of the microelectronic system at the upper surface. This
`may be achieved by proper construction of the microelec(cid:173)
`tronic components, encapsulation etc.
`[0040] The constructions shown in FIGS. 8, 9, 10, 11 and
`12 are particularly suitable for microelectronic systems
`including an element, e.g. an electrode which should have
`skin contact.
`[ 0041] FI GS. 13-18 illustrates an embodiment of the inven(cid:173)
`tion where an antenna, a Central Processing Unit, a battery
`and electrodes are embedded in an adhesive device. FIG. 13
`illustrates the two-dimensional shape of the device indicating
`a cross-section by A-A. In FIG. 15 the third dimension is
`shown as the cross-section A-A. The circle B from the rim of
`the device is further magnified in FIG. 16 and the circle C of
`the centre is likewisemagnifiedinFIG.17. FIG.14 illustrates
`the position of the antenna placed in the outer part of the
`adhesive device and being connected to the central part of the
`microelectronic system. FIG. 16 shows more in detail the
`building of the antenna lying embedded in the adhesive. FIG.
`17 shows the position of the central part of the microelec(cid:173)
`tronic system with a battery, a CPU and an electrode protrud(cid:173)
`ing the adhesive. The battery and the CPU are enveloped in a
`transparent silicone rubber. Finally FIG. 18 illustrates the
`adhesive device in a three-dimensional mode.
`[0042] FIG. 19 shows one embodiment of a sensor assem(cid:173)
`bly according to the invention seen in a exploded perspective
`view.
`[0043] FIG. 20 shows the embodiment of a sensor assembly
`in a sectional view along line XX-XX in FIG. 19.
`[0044] FIG. 21 shows the embodiment of a sensor assembly
`seen from the bottom.
`[0045] FIGS. 22a and 22b shows another embodiment of a
`device according to the invention wherein FIG. 22b shows a
`portion of FIG. 22a in an enlarged view.
`[0046] FIG. 23 shows yet another embodiment of a device
`according to the invention seen in a perspective view.
`[0047] FIG. 24 shows the embodiment of a device accord(cid:173)
`ing to the invention in a sectional view along line XXIV(cid:173)
`XXIV in FIG. 23.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`[0048] The present invention relates to adhesive devices
`having a microelectronic system embedded in an adhesive
`body made from a pressure sensitive adhesive.
`[0049]
`In the following the term "three-dimensional" used
`when defining an element e.g. an adhesive body or device,
`refers to an element having a considerable varying contour
`when seen in cross section. Thus, for example a three-dimen(cid:173)
`sional adhesive body will have a maximum thickness and a
`minimal thickness. According to the invention the maximum
`
`thickness will be at least twice the thickness of the minimal
`thickness. In a preferred embodiment the outer rim or the
`peripheral edge of the adhesive device has a thickness which
`is less than halfof the thickest part of the sensor, normally the
`central part.
`[0050]
`In contrast to the term "three-dimensional" the term
`"two-dimensional" used when defining an element refers to
`an element, which has a generally planar surface. Thus, the
`maximum thickness of a two-dimensional adhesive body is
`below two times the minimal thickness of the adhesive body.
`[0051] As used herein in relation to the micro electronic
`system or components thereof, the term "embedded", means
`that the pressure sensitive adhesive of the adhesive body is
`surrounding all or some of components of the micro elec(cid:173)
`tronic system, either partly or fully. Thus, the term embedded
`covers the situation where all sides of the system or compo(cid:173)
`nent(s) is covered by the adhesive of the adhesive body and
`also the cases where not all sides of the embedded item is
`covered with the adhesive of the adhesive body, e.g. when the
`item is placed in a recess or cavity in the adhesive body and is
`accessible from the outside.
`[0052] As "embedded" is the general term used for the
`description of the way the micro electronic system is posi(cid:173)
`tioned in the adhesive body the term "integrated" means that
`the micro electronic system or specific components thereof
`are covered by adhesive on all sides and the term "applied" is
`used when the micro electronic system only is partly covered.
`[0053]
`Integrated and covered on all sides also covers the
`situation where the integrated component is connected, e.g.
`electrically or otherwise to another component embedded in
`the adhesive body.
`[0054] As used herein, a microelectronic "sensing" system
`means a microelectronic system comprising a transducer hav(cid:173)
`ing an element capable of detecting a physiological or neu(cid:173)
`rological condition.
`[0055] As used herein through hole means a hole through
`the adhesive body having opening(s) at the upper surface of
`the adhesive body and opening(s) at the bottom surface of the
`adhesive body. Preferably the through hole has one opening at
`the upper surface and one at the bottom surface of the adhe(cid:173)
`sive body. The through hole may have any suitable shape.
`[0056] By the "thickness" of the adhesive device is meant
`the length of the shortest line which may be drawn between a
`specific point on the upper surface to a point on the bottom
`surface, or the shortest line which may be drawn between a
`specific point on the bottom surface to a point on the upper
`surface.
`[0057] For the purpose of the present invention the expres(cid:173)
`sion "skin" is used to designate the outer surface of mammals.
`[0058] As mentioned above, it has surprisingly been found
`that a wire-less microelectronic systems in which the micro
`electronic parts are embedded in a three-dimensionally
`shaped pressure sensitive adhesive body solve the problems
`of the known sensor devices.
`[0059] Due to the properties of the three-dimensional pres(cid:173)
`sure sensitive adhesives, an optimal protection of the micro
`electronic system is created. The adhesive provide sealing
`towards the skin surface and the adhesive device is protected
`from exterior liquids due to the polymeric cover layer(s) on
`top of the adhesive device. Furthermore the adhesive protects
`the embedded micro electronic parts from mechanical dam(cid:173)
`age.
`[0060] The adhesive bodies according to the invention are
`made from pressure sensitive adhesives that are shaped three-
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`US 2008/0275327 Al
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`Nov. 6, 2008
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`4
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`dimensionally, having a varying thickness from the centre to
`the peripheral edge of the adhesive body and having the micro
`electronic sensing system embedded within the adhesive
`body, suitably where the adhesive body is thickest.
`[0061] A device with such a shape and suitably with bev(cid:173)
`elled edges provides a smooth interface with the skin. The
`adhesive device will give a gentle feel and will not tend to give
`friction to clothes and linen. A special advantage will be that
`the adhesive device will less easily involuntarily fall off due to
`bulkiness and adhesiveness at the edge. This is very important
`to the very function of the device.
`[0062] Moreover, the construction of the adhesive device is
`simple and convenient as the adhesive body have a triple
`function as the means for fixation of the device to the skin, the
`means for protection of the microelectronic system and the
`means for shaping the device into a convenient shape. The
`construction require less components and process steps in the
`assembly of the three-dimensional device and is therefore less
`expensive and easier to manufacture.
`[0063] According to one embodiment of the invention, the
`three-dimensional adhesive body has an essentially planar
`bottom surface adapted to adhere to the body surface of a
`mammal and an smooth upper surface. The adhesive device is
`suitably thickest at the central part of the body and thinnest at
`the periphery of the body.
`[0064] Preferably, the upper surface has a smooth convex
`surface, but it may in principle take any form.
`[0065] The outer rim or the peripheral edge of the adhesive
`device must be shaped to a thickness less than half of the
`thickest part of the sensor, normally the central part.
`[0066] Thus, in a further embodiment of the invention, the
`thickness of the adhesive device at the periphery is less than
`50% of the thickness of the adhesive device where it is thick(cid:173)
`est, suitably the thickness at the periphery is less than 25% of
`the thickness of the adhesive device where it is thickest,
`preferred the thickness at the periphery is less than 10% of the
`thickness of the adhesive device where it is thickest, and most
`preferred the thickness at the periphery is less than 5% of the
`thickness of the adhesive device where it is thickest.
`[0067] The thickness at the periphery of the adhesive
`device is typically under 0.4 mm. In one embodiment the
`thickness may be between 0.01 and 0.4 mm. Suitably, the
`thickness at the periphery of the adhesive device is above 0.05
`mm, preferably between 0.05-0.4 mm.
`[0068] Typically the adhesive device is between 0.5 and 15
`mm, more suitably between 1-5 mm where it is thickest,
`typically but not necessarily, at the centre of the adhesive
`body.
`[0069] Suitably, the angle between the bottom surface of
`the adhesive device and a line drawn from any point of the
`circumference of the bottom surface and the point at the upper
`surface where the adhesive body is thickest is below 60
`degrees, preferably below 45 degrees and most preferably
`below 30 degrees.
`[0070] The outer rim of the adhesive body may suitably be
`shaped circular or oval, with or without flaps and lobes, or it
`may be shaped rectangular or triangular to obtain as conve(cid:173)
`nient and safe a device as possible.
`[0071] Normally the outer rim of the adhesive body will
`consist of the adhesive of the adhesive body. However, there
`may be embodiments where the microelectronic system or
`component(s) thereof, is placed in/or at the outer rim,
`whereby the outer rim does not solely consists of the adhesive
`of the adhesive body.
`
`[0072] The pressure sensitive adhesive making up the
`three-dimensional adhesive body is suitably a mouldable
`thermoplastic or chemically curing pressure sensitive adhe(cid:173)
`sive having a flexibility enabling the adhesive device to con(cid:173)
`form to the curvature of body parts while retaining its adhe(cid:173)
`sive properties even under movements.
`[0073] Suitable, pressure sensitive adhesives making up the
`adhesive body is an adhesive based on polymers selected
`from block-copolymers such as styrene-block-copolymers,
`and hydrogenated styrene-block-copolymers, amorphous
`poly-alpha-olefins (APAO), polyacrylics, polyvinylethers,
`polyurethanes, polyelhylenevinylacetate, silicone or from the
`group ofhydrogel pressure sensitive adhesives.
`[0074] Pressure sensitive adhesives based on these poly(cid:173)
`mers are known and the skilled person knows how to prepare
`adhesives based on these polymers.
`[0075] The block-copolymers, such as styrene-block-co(cid:173)
`polymers, and hydrogenated styrene-block-copolymers, may
`suitable be selected from Styrene/ethylene-Butylene/Styrene
`(SEBS), Styrene/Isoprene/Styrene (SIS), and Styrene/Ethyl(cid:173)
`ene-Propylene/Styrene (SEPS).
`[0076] The adhesive may also be based on PDMS (poly(cid:173)
`dimethylsiloxane ), and may suitably be a PDMS gel.
`[0077] Hydrogel adhesives may also be based on or com(cid:173)
`prise amfifilic polymers, polyvinylpyrrolidone, polyvinyl
`alcohol, polyethyleneoxide, gelatins, natural gums and cellu(cid:173)
`lose derivatives or any combinations thereof.
`[0078] The pressure sensitive adhesive may be formulated
`according to the principles and based on the polymers listed
`and disclosed in the handbook ofDonatas Satas: Handbook of
`pressure sensitive adhesive technology, Third edition.
`[0079]
`In one particular embodiment of the invention, the
`pressure sensitive adhesive making up the adhesive body
`comprises hydrocolloids. The pressure sensitive adhesive
`comprising the hydrocolloids may be any of the above-men(cid:173)
`tioned types of pressure sensitive adhesive or any other pres(cid:173)
`sure sensitive adhesive known in the art.
`[0080] Thus, U.S. Pat. No. 3,339,549 discloses a blend of a
`rubbery elastomer such as polyisobutylene and one or more
`water-soluble or water swellable hydrocolloids such as a
`powdery mixture of pectin, gelatine and carboxymethylcel(cid:173)
`lulose. The adhesive mass has a water-insoluble film applied
`to one surface. A composition of this type is available com(cid:173)
`mercially from E.R. Squibb & Sons Inc. under the trademark
`"Stomahesive" and is used as a skin barrier around stomas to
`prevent skin breakdown by the corrosive fluids discharged by
`the stoma.
`[0081]
`In adhesive compositions of this type, the poly(cid:173)
`isobutylene is responsible for provision of the adhesive prop(cid:173)
`erties and the dispersed hydrocolloid powders absorb fluid
`and render the adhesive agent capable of also adhering to
`moist skin (wet tack). These compositions are also gaining
`increasing acceptance as wound dressings for dermal ulcers,
`bums and other exuding wounds.
`[0082]
`In a number of embodiments, styrene copolymers
`have been incorporated which are disclosed in a number of
`patent references.
`[0083] Thus, U.S. Pat. No. 4,231,369 Sorensen et al. dis(ci