Medical Wearables & Skin Interface

It depends on the wear-time and the skin. Use a silicone skin adhesive for short wear, sensitive or fragile skin, or a patch that is removed and repositioned: it holds gently and releases with low trauma, so it is kind to the skin but does not build the strongest hold. Use an acrylic skin adhesive for long, secure multi-day wear where edge-lift must be resisted: it builds adhesion over time and holds firmly, at the cost of being more aggressive on removal.

A hydrocolloid is chosen where moisture management is the limiter. The deciding questions are the wear duration, whether the patch is repositioned, and the skin's sensitivity. Choosing by default rather than by wear-time is the most common wearable failure: too aggressive irritates sensitive skin on a short patch, too gentle lifts at the edge on a long one. Peel is reported per ASTM D3330, and both adhesive types are referenced to ISO 10993-10 (sensitization) and -23 (irritation) at the material level.

A specific PSA family is named only where catalog-verified.

Breathability, measured as the moisture-vapor transmission rate (MVTR), is what lets sweat escape from under a patch instead of building up against the skin. On a multi-day patch, trapped moisture macerates the skin (it becomes soft, white, and waterlogged) and undermines the adhesive, so the patch lifts. A breathable cushion (a microcellular polyurethane or silicone foam with a high MVTR) paired with a breathable or perforated skin adhesive lets the moisture pass through, which reduces both maceration and edge-lift and extends comfortable wear.

The MVTR the stack needs rises with the wear-time, the wearer's activity, and the humidity of the environment, so an active wearer or a long patch needs more breathability than a short, sedentary one. State the wear-time, the wearer activity, and the moisture environment so the cushion and adhesive carry enough MVTR. MVTR is a maker-TDS property characterized per ASTM E96; H-O can build a breathable cushion and a breathable or perforated adhesive into the converted stack.

For a part worn against intact skin for hours to days, the two endpoints that matter most are ISO 10993-10 (skin sensitization, whether the material triggers an allergic immune response) and ISO 10993-23 (irritation, whether it physically or chemically irritates the skin), with ISO 10993-5 (cytotoxicity) as the baseline screen.

A skin-worn patch is a surface-contact device, and its contact duration (limited, prolonged, or permanent under ISO 10993-1) sets how thoroughly it is evaluated, but for the skin layers the sensitization and irritation endpoints are the headline.

So the skin-side cushion and the skin adhesive both want grades referenced to ISO 10993-10 and -23, and a USP Class VI designation is a useful material-level reference too. State that the part is skin-contact, the wear duration, and that you need at least the -10 and -23 endpoints, and H-O references grades and adhesives whose makers evaluate them against those endpoints.

The material maker evaluates the grade; the device maker owns the finished-device biocompatibility of the assembled patch.

A wearable skin patch is a stack, built body outward: a skin-side adhesive, a cushion foam, a face film or carrier, and a release liner, with the device or electronics carried on or above it. The H-O parts are the cushion and the adhesive and seal layers, converted to your drawing. To build it, H-O laminates the skin adhesive to the cushion, the stack outline and any sensor or window openings, and kiss-cuts the part on a release liner so the assembly line can peel and place it as one piece.

The structural bond between layers is a transfer or double-coated tape. This mirrors the standard skin-patch construction described across medical-converter wearable literature; it is a reference construction, not proprietary customer CAD. State the layer order, which faces carry adhesive, whether the adhesive is breathable, and how the part ships (kiss-cut on liner, in sheet or roll), and H-O builds the multi-layer stack, it, and kiss-cuts it on liner to your drawing.

Edge-lift before the intended wear-time usually comes from one of two things: the wrong skin adhesive for the wear duration, or a non-breathable stack that traps moisture. A gentle silicone adhesive chosen for comfort may not hold a multi-day patch through motion, and trapped sweat undermines any adhesive at the edge first.

The fix is to match the adhesive to the wear-time, an acrylic skin adhesive that builds adhesion and holds for long, secure wear and resists edge-lift, while reserving the gentle silicone adhesive for short or sensitive-skin wear, and to make the stack breathable so moisture does not lift the bond.

It also helps to round the patch corners (a detail H-O can add) because sharp corners peel first, and to size the adhesive area to the device weight and motion. State the wear-time, the wearer activity, and the moisture environment so the adhesive and breathability match. Peel is reported per ASTM D3330; the skin adhesive is referenced to ISO 10993-10 / -23 at the material level.

H-O references material grades by designation and assembles documentation aligned to your requirements. For a skin-worn part, state that it is skin-contact, the wear duration, and the basis you need, at least ISO 10993-10 (sensitization) and -23 (irritation), with ISO 10993-5 (cytotoxicity) and a USP Class VI designation as appropriate, and H-O sources a cushion grade and a skin adhesive whose makers evaluate them against those endpoints and provide the material TDS, certificate of conformance, and lot traceability.

The important distinction is who owns what: the material maker evaluates each grade at the material level, and the device maker owns the finished-device biocompatibility, including the assembled patch where multiple materials and the adhesive come together. H-O is an ISO 9001:2015 certified converter; it does not independently certify materials and does not certify finished devices, and it does not claim an ISO 13485 certification, an FDA device registration, or a cleanroom certification.

Customer-specified compliance packages are assembled on request.

A microcellular polyurethane such as PORON medical is the standard skin-side cushion for a wearable because it gives controlled, soft force-deflection at low stress and has low compression set, so it conforms to the body, distributes the device's weight without a pressure point, and recovers over days of wear instead of flattening.

A cushion that takes a set gradually loses its thickness under the constant pressure of an on-body device, so the device starts pressing harder on one spot and becomes uncomfortable or marks the skin, ending wear early regardless of the adhesive.

The fix is to choose a low-compression-set cushion and size the grade and gauge to the device weight and the contact area so it keeps distributing the pressure for the full wear-time, and to make it breathable so it also manages moisture. A soft silicone foam is the silicone-based alternative. State the device weight, the contact area, and the wear duration so the cushion grade matches.

Force-deflection and compression set are maker-TDS properties characterized per ASTM D1056.

Yes, that is the core of what H-O does for wearables. H-O laminates the skin adhesive to the skin-side cushion, builds up the multi-layer stack (cushion, face film, structural bond, and any barrier or electronics-cushion layer), the stack outline and any sensor or window openings, and kiss-cuts the finished part on a release liner so your line can peel and place it as one piece.

The structural bonds within the stack are transfer or double-coated tapes. State the layer order, which faces carry adhesive, whether the skin adhesive is breathable or perforated, the openings the patch needs, and how it should ship (kiss-cut on liner, in sheet or roll). Where any adhesive sits in skin contact, it is referenced to the relevant ISO 10993 skin endpoints at the material level.

Multi-layer lamination, die-cut, and kiss-cut-on-liner are the standard H-O converting operations that turn the layers into one finished, place-ready patch part.

They can be, and it changes the spec. A perimeter seal that sits against the body is a skin-contact part, so it wants a grade referenced to the skin endpoints (ISO 10993-10 and -23) just like the cushion and adhesive, in a soft cellular-silicone or silicone-foam grade that conforms and seals under the gentle pressure a wearable applies. A housing seal that is internal and never touches skin (it only keeps moisture off the electronics) has a lighter contact requirement, though it still wants a clean, moisture-resistant grade.

The deciding question is whether the seal is skin-contact or housing-only. State which it is, the closure pressure the wearable applies, and the moisture environment, so H-O references the right grade: a skin-contact perimeter seal gets the full skin-endpoint reference, a housing-only seal gets a grade chosen for sealing under low closure force. A soft medical cellular silicone (BISCO MS-80 / MS-96) is the usual perimeter seal; a solid silicone is a thin cleanable housing-edge seal.

Die-cut bonding tapes hold the layers of the stack together and the device to its carrier. A thin acrylic transfer tape (adhesive only, no carrier) gives a strong, low-profile bond between two compatible flat layers; a double-coated tape (a carrier with adhesive on both faces) gives a thicker, more forgiving bond and is the choice for bonding dissimilar layers or surfaces that are not perfectly flat.

The bonding tape is chosen for the substrates, the bond strength, the flex and shear an on-body device sees, and any contact basis if it sits near skin; a low-surface-energy plastic in the stack needs a differential or LSE-capable grade. State the layers to bond, their materials, and the stress, and where a layer is low-surface-energy name it. H-O the bonding tape to its frame and laminates it into the stack.

Peel and bond strength are reported per ASTM D3330; the wrong or too-thin bond is a common cause of stack delamination.

No. H-O Products is a precision converter: it makes the skin cushions, skin adhesives, seals, bonding layers, and electronics cushions to your drawing from material grades and skin-contact adhesives commonly used in wearables, under an ISO 9001:2015 quality management system. H-O is an ISO 9001:2015 certified organization; that certification governs the converting process, not a device clearance.

H-O does not make finished wearable devices and does not claim an ISO 13485 certification, an FDA device registration or clearance, or a cleanroom certification.

Material grades and skin adhesives are referenced by designation to ISO 10993 (especially -10 and -23 for skin), USP Class VI, and FDA contact frameworks at the material level, where the material maker performs the evaluation. The finished-device biocompatibility, including the assembled patch, the skin-contact validation, and the regulatory file belong to the device maker. H-O supplies the converted parts, the material documentation, and lot traceability aligned to your requirements.

Send the wearable drawing or a sample, the layer or the full stack you need, and the key facts: the layer (skin cushion and adhesive, perimeter or housing seal, structural bond, or electronics cushion), the wear-time on skin and whether the patch is repositioned, the skin and moisture condition (normal, sensitive, or high-moisture/active), and the skin-contact basis (at least ISO 10993-10 and -23, with USP Class VI or an FDA basis as needed).

Add the device weight and contact area for the cushion, the closure pressure and whether the seal is skin-contact, the substrates and stress for any bond, the openings the patch needs, the adhesive faces and whether they must be breathable, and the prototype and annual volume. With that, engineering returns a material family for each layer, a skin-adhesive direction, a converted-part approach (including the multi-layer stack and how it ships), prototype lead time, and the documentation that can be aligned to your requirements.

The quote form below has fields for each of these. Samples typically ship in 3 to 5 business days; standard production in about 2 weeks.