right, that was one of my other suggestions in the comments, quite easy to pull off also since a robot doesn't suspect it just does so it walks or hops right into it. Hell fill it with oily water and the thing is fucked never getting out and likely fries it's circuitry and if you put bungy sticks at the bottom definitely ripping insulation off the wiring or puncture the pneumatic lines in some way. Also just drop an extension cord plugged in into the water and bye bye robot. If controlled remotely then arrow into the person even a non lethal area will make them hurt so bad they cannot concentrate enough to do shit correctly. Hell the old aerosol can and a bic lighter will fuck with it's brain to no end especially if it has heat sensors.