first working on how to send bitcoin when there no internet /blockstream or electricity or limited battery using offline small device first - if that succeeds then think of other stuff
Discussion
We all have different priorities for what to build next and that's a good thing 👍
"using bitcoin without/limited energy" far more important since bitcoin itself is not an energy.
We have that, its #satscard.
can that work without any electronic device (temporary )
Yes, buy one from @NVK and try it. Its really cool, fully offline. Easily verifiable and reusable 10 times. Its based on secure silicon.
Been using Satscards for sometime I load the cards up with different denominations if you plan on being off grid works great!!! You just hand over the card an exchange for goods/services