Prototype of Athena, ESA's tiny pinhole thruster, will be available by end of 2024

https://phys.org/news/2024-01-esa-tiny-pinhole-thruster-ready.html

"palm-sized, maneuvering and propelling cubesats, small satellitesand probes of up to 50 (goal: 300) kg mass, once they are in space... each of 6 thrusters fit on face of 10-cm cubesat has 7 emitter arrays etched onto silicon wafers, each housing 500 pinholes emitting electrically charged particles from conductive salt (electrospray) producing 20 km/s thrust... highly adjustable and reconfigurable in flight... eco-friendly non-toxic liquid propellant, no pressurized storage tanks"