Smuggled in a knife... highly unlikely but possible. Cutting through steel bars with a knife- impossible! Cutting through an inch or more of ballistic polymer- impossible! It's not humanly possibly to manage such a feat.
Now... maybe if it was bars, a diamond embedded strand of carbon fibre wire would be easy to secrete and you could then slowly, ever so slowly saw through the bars. If it's a sheet of transparent ballistic polymer... well, a string saw isn't going to be much help.
Maybe a hidden vial of acid, allowing one to reach out and around to the control panel. Then by paying attention to the pattern of beeps one might be able to surmise the opening code (provided of course it isn't a card + passcode system or a biometric keypad.)
Now... maybe if it was bars, a diamond embedded strand of carbon fibre wire would be easy to secrete and you could then slowly, ever so slowly saw through the bars. If it's a sheet of transparent ballistic polymer... well, a string saw isn't going to be much help.
Maybe a hidden vial of acid, allowing one to reach out and around to the control panel. Then by paying attention to the pattern of beeps one might be able to surmise the opening code (provided of course it isn't a card + passcode system or a biometric keypad.)