Objectives: In this paper, to figure out the reliability of copper wire wound coil in an in vitro environment, performance deterioration and copper ion elution of coil was investigated using accelerated tests.
Methods: Bare coils with enamel coating and parylene-C coated coils were immersed into the 75-degree Celsius phosphate-buffered saline for accelerated tests. Performance and elution of the copper ion were investigated using proper equipment.
Results: The parylene-C coating with a thickness of several um effectively depress the performance degradation and the elution of the copper ion. However, it has not reached a perfect level and research on additional packaging methods is needed.
Significance: Coil for wireless power and data transfer is an important element in the design of implantable devices. Copper is the most widely used material for the design of coils in general. However, because of its cytotoxicity and high reactivity with water, the packaging capabilities should be investigated closely. In this paper, a method for evaluating the packaging performance when the coil is coated with parylene-C and the results are presented.