Within our current realiy I am pretty sure physical interactions that lead to consciousness are only possible with carbon and silicon.
Luckily, I believe we live a just a subset of possible realities - and all are digital btw. If we die, we might get to choose to live in a fantasy world with completely different rules.
To correct myself, I believe we are in one of the many parallel worlds running on some infrastructure in the above layer reality. Time scales might be different based on allocated computing power - and I'd say our universe sure has a lot of allocated power to simulate such detailed experiences for over 7 billion people - but scale is arbitrary from within.
Personally I strongly believe in parallel realities and the idea of different races of beings occupying the same physical space as our world but on a different "frequency" so we're only very occasionally aware of them as they are of us.