How is this different from the Sharp Memory LCDs?
Using numbers from Sharp[0], Memory LCDs use ~226µJ/cm2 each second when static. I'm assuming they are 60Hz displays & therefore require a refresh 60 times each second but even if they only refresh once a second, that's ~3.8µJ/cm2 a second or 13,680 times the power consumption of the Rdot displays.
The article claims these Rdot screens use 0.25mJ/cm2 every 15 minutes when static.
Again, these are my "back-of a napkin" calculations so take with some salt.
[0]https://www.sharpsma.com/products?sharpCategory=Memory%20LCD
Sharp Memory LCD is 200uA vs rdot at 0.25ua.
With AA batteries Sharp Memory is only going to last 1 year MAX. That's too short for most consumer applications. Where rdot is much less than the self discharge. So 5-10 years.