Larry Niven's stasis field
The stasis field is the engineer's dream. Put a stasis field around a wet noddle and you have something that can not bend or break and will never corrode. A soldier or space traveller can get into the most dangerous situation but at the click of a button, transition into perfect safety. It's a cool idea but dangerous from a plotting standpoint. It has the same problem as the magic ring in fantasy. The character can get into an impossible situation and then all he has to do is put on the magic ring, say "abracadabra" and the problem goes away. For the most part Larry Niven avoided that trap with the stasis field.
Gary