DELO releases IBOA-free medical adhesive for glucose monitoring sensors and other wearables

DELO has released a new light-curing medical-grade adhesive engineered with nontoxicity in mind. DELO PHOTOBOND MG4047 is designed for wearable medical applications such as glucose monitoring sensors (CGM). Its chemical properties and impermeable characteristics help prevent skin irritation in cases of media influence such as rain or sweat.

With a 230-MPa Young’s modulus and a 200% elongation at tear while maintaining a 9-MPa compression shear strength, DELO PHOTOBOND MG4047 manages to be both a highly flexible and decidedly strong adhesive. These physical properties enable it to prevent common problems associated with wearable sensors such as sensor drift, which can occur following potting.

Chief among its advantages is that it is IBOA-free. IBOA, or isobornyl acrylate, is a chemical compound found in many polymer materials and is considered an extractable material. If medical wearables worn by patients are exposed to external media such as rain or sweat, tiny particles may leak out and contact the skin, causing adverse reactions such as irritation or allergies. Being free from IBOA reduces the risk of such reactions.

DELO PHOTOBOND MG4047 also demonstrates its nontoxicity through its biocompatibility, meeting the requirements outlined the DIN EN ISO 10993-5 cytotoxicity test. It complies with EU RoHS Directive 2015/863 as well, which is used to ensure nontoxicity in substances used in electronic equipment.

In addition to biocompatibility, DELO PHOTOBOND MG4047 achieves low water absorption at 0.15 wt%, resulting in low water permeation at 13 (g·mm)/(m²·24h). This creates a high water vapor barrier and prevents potential contact with other leachable substances.

The curing properties of this light-curing adhesive are optimized for mass medical wearable production with a required irradiation time of as little as two seconds under a 365–400-nm LED light with an intensity of 1000 mW/cm².