Not in this specific case.

> We fabricate such physically transient electronics systems using degradable polymers, compostable conductors and dissolvable integrated circuit chips that naturally vanish into environmentally benign end products when exposed to water

This particular design isn't supposed to breakdown into microplastics, and builds on their work of biodegradeable pacemakers.

The overwhelming majority of microplastics come from larger objects degrading through use or exposure to the elements (mostly tyres and synthetic clothing, but also disposable plastic exposed to UV).

They're not actually "micro"-sized out the factory.

The article specifically discusses dissolvable components at the end.

This comment is not any more appropriate to this thread than any thread involving a product using plastic. Just because the product is small and made of plastic parts doesn't mean it produces more micro-plastics.