Hello from Hanna:
"When the course "Packaging" popped up during my time at the university, no one in my class had any idea what we were going to learn. Google didn't give any obvious answers either. I figured out: I love this subject! We had a great professor who genuinely loved his proffesion and was always available for questions.
Packaging is (simply put) the art of picking the right materials for its purpose. Some materials transfer current, others isolate, both will expand when exposed to heat. Electronics going into the soil will need different protection from its environment than electronics going inside living beings (eg. pacemakers).
Our fish health monitoring system is designed to not kill its host: It is biocompatible. I have enjoyed almost every minute of working on it in order to make it so."
The environment inside a body demands that the encapsulation of electronics to be:
Hydrophobic (Waterproof)
Chemically stable
Dielectric (Insulator)
Bacterial resistant
The packaging of the electronics is important to make sure both the fish and system don't kill each other. Any moisture can cause a short circuit, and many materials will cause inflammation and/or damage to the hosts' tissue.
When choosing material for the encapsulation, all the criteria listed above had to be met, also we want our engineers to be working with the least hazardous materials available. Both biocompatible epoxy and biocompatible silicone have been tested. An issue that appeared was air bubbles within both materials, but with some science and engineering, the bubbles were gone.
We tested the encapsulation with and without dummy pieces, to determine how and if the airbubbles would get caught in the chip, batteries etc, and the end result came out great!
Silicone and epoxy vary in viscosity, hardness and curing process, which means that the procedure for encapsulation in epoxy is different than the procedure for encapsulation in silicone. Not all silicone is biocompatible, but the type we went for is. In addition, the production of silicone does not create microplastics, which is nice for the environment (Double win!).
Packaging is also included in the process of making the wire sensor, but that's a topic for another post.
Until next time,
Hanna T. Bråthen,
Engineer at ZP
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