You could cheat a little, and use drones. Those self-destruct when their supplies are used up. Just launch a few of those drones with repair abilities, and it'll patch you up a little, then go boom.
Ashton's idea is plausible. Design a specific repair component that takes up a whole drone (with "bridge" ability as well) and have it's supply storage equal to the default per turn usage of drones in setting.txt - this should allow the drone to exist for a single turn only.
Destroyed on use will not work, it only works with components that are activated by menu buttons.
Giving the drones a set of one-turn-worth supply storage components and a set of smaller, one repair-per-turn repair bays is a nice alternative too.
The player then has to decide whether they want to design a drone that can repair 2 per turn for just two turns, or a drone that can repair 1 component per turn for 6 turns.