"Gravy gun".
(The name gravy gun comes from the Schlock Mercenary webcomic; the description below matches the description and technical glimpses disseminated in the webcomic)
Once you have artificial gravity, weaponizing it is reasonably straightforward. Point a gravity plate against someone, and they'll immediately feel a force towards the plate (or in the opposite direction). Due to the well-known F=ma relation, they will also be accelerated in the same direction.
Invert the polarity of the plate; the acceleration will be reversed.
Nothing whatsoever happens to the target because (and only as long as) it's completely immersed in an isotropic field.
But if you can achieve spatial anisotropy (using several parallel beams of different polarity) or temporal anisotropy (using wavelengths of the same order of magnitude as the target's size), the target will experience a violent shaking, against which nothing (except an accurately countermodulated grav field of the same local intensity) will work.
"Violent shaking" can go from disturbing, to more or less permanently incapacitating, to lethal. At the same time, the effect is much less dangerous on inanimate objects.
...and, immobilizing foam.
Used as boarder-repeller, the foam gun shoots what is essentially fast-setting superglue. The foam has some additional features though: it expands very much, resists to very high temperatures, and is thermally insulating.
This means that people in power armor cannot free themselves, and remain encased in a substance that, in a comparatively short time, will cause them to pass away and even die from heatstroke (with no way of getting rid of extra heat, the enclosed volume's temperature will just go up and up). The victims' situation can be monitored from outside using microphones, and the appropriate solvent administered to capture the victims once they are well and truly incapacitated.
