- Cheap small scale electronics: imagine raspberry pi-like devices with a sticker form factor, and very cheap, energy efficient enough to be powered by the sun. Can't think of a useful use-case, but kinda cool to shrink things like that

- Differential privacy

- Quantum computing

- Programs that can replace programmers

- ML for biotech

- Automated fabrication

From a more social perspective, in order of least to most abstract:

- Software that helps improve public infrastructure, logistics somehow - eg identifying ways to minimize small amounts of energy waste on a wide scale

- Tools that help local municipalities and citizens cooperate together

- Tools that give the disenfranchised a greater voice