The Surge

This is easily farmable in the Resolve Biolabs level:

1. Unlock the exo-lift that takes you from the Resolve Biolabs' train station to the Resolve Biolabs area (where all the greenhouses are).
2. Go left out of the building where the exo-lift takes you, avoid the toxic waste as much as possible, and kill the Rhino enemy and patrolling Lynx enemy near the big stairwell.
3. There will be two security bots patrolling nearby. Pull one at a time and fight in the area where the Rhino enemy was. First thing to do is target its tail and destroy it. After that, the fight solves itself... the security bot will jump at you, your avoid it, you damage it some, repeat. When you destroyed the bot's tail, it can be picked up as an implant so be sure to do that.
4. There are two paths after this: one to the right which is where the Smelter bot is and one directly ahead where you talk to Dr. Chavez. Take the latter.
5. Go around the left corner from there and there will be another security bot. Lure it towards the terminal you spoke to Dr. Chavez on and fight there... same tactics as in step #3.
6. To the left of Dr. Chavez' build is an inactive security bot. It looks like it is scrap but its lights are still on. Approach it and it will wake up and start to fight you. Defeat it.

Each security bot drops 1300 tech scrap and the implant it drops can be destroyed in the game menu for 1000 tech scrap. And there's a decent rate of scrap kits dropped by regular enemies too.

Per run, you get almost 10000 tech scrap, which is 20% of this trophy's goal. Also, don't worry if you die during this farming. The shortcut in the train station gives quick access back to the greenhouse area with time to spare.

One important note: later on in the level, two of the security bots will be replaced by flamethrower enemies. So be sure to do this farming as early as possible, or you'll only have two security bots to farm instead of four.