Project Image:
Title of the project:
Influence of the aging of adhesives on the cleanliness and biocompatibility of surgical instruments (Biocaadh - biocompatibility of aged adhesive joints)
Project name:
Project leader:
Joana Hummel
Project management:
  • DVS - Deutscher Verband für Schweißen und verwandte Verfahren
Funding reference number:
19.672 N

In medical technology, which is strongly dominated by medium-sized companies, bonding technology is finding an ever-increasing range of applications. Many modern instruments, e.g. for minimally invasive surgery, can only be manufactured using adhesive bonding as a joining technique, for example when medical steels are joined with medically approved plastics.
However, the question of the durability, cleanliness and biocompatibility of the bonding area and the adhesive with regard to cleaning and sterilisation poses a problem and obstacle for the further use of bonding technology.


The distributor of medical devices guarantees the safe use of the products until the end of their life cycle, i.e. the latter is responsible for ensuring that the product does not cause any damage to the body.
In order to obtain approval for a glued medical product, the manufacturer or distributor of the medical product must provide various proofs in addition to the functional capability:
- Biocompatibility of the adhesive bond in combination with the materials used depending on pre-treatment and handling of the adhesive (mixing, curing, ...)
- Cleanability of the medical device (accessibility for the cleaning/removal of residues from the various process steps in cleaning cascades/validation of the cleaning process)

Both the tests of the pure adhesive and the bonded product are carried out in the unaged state. Therefore, the question of guaranteeing the properties during use, i.e. in particular after preparation (cleaning and sterilisation), arises.

The focus of the planned project is the hydrothermal ageing of the adhesives as a result of aqueous cleaning and sterilisation using autoclaves.

The questions raised about the ageing resistance of the adhesive bond and in particular the effects on the biocompatibility of aged adhesive joints concern both the manufacturers of medical products and the approving authorities with regard to ongoing tightening of the approval criteria. In the planned project, a prototype procedure for the assessment of the biocompatibility of aged (by cleaning and sterilisation cycles) adhesive compounds will be developed and interactions between adhesive, preparation and medical environment will be investigated. The results of the project will create a basis for the improvement and, if necessary, new development of glued medical products. The clarification of the aging mechanisms increases the safety when using medical devices on patients.