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Novel method for plasma etching of printed circuit boards as alternative for fluorocarbon gases
(2023)
Feasibility of Parylene C for encapsulating piezoelectric actuators in active medical implants
(2023)
Parylene C is well-known as an encapsulation material for medical implants. Within the approach of miniaturization and automatization of a bone distractor, piezoelectric actuators were encapsulated with Parylene C. The stretchability of the polymer was investigated with respect to the encapsulation functionality of piezoelectric chips. We determined a linear yield strain of 1% of approximately 12-μm-thick Parylene C foil. Parylene C encapsulation withstands the mechanical stress of a minimum of 5×105 duty cycles by continuous actuation. The experiments demonstrate that elongation of the encapsulation on piezoelectric actuators and thus the elongation of Parylene C up to 0.8 mm are feasible.
In the course of researching a bellows to encapsulation the mechanical unit of a moving active implant, two photopolymer resins were calibrated for further investigation as part of this research. This has been done using a masked stereolithography (MSLA) printer, cleaning steps followed by curing. The resins were one biocompatible and the other with special flexibility. The evaluation of the printing was carried out using a validation matrix for SLA printing processes. The time required for the process steps had been observed as well. Both resins were calibrated with respect to their exposure time and the process chain was evaluated. The results are meaningful, but additional factors had been identified that need to be considered too.