Perhaps you should try some spelling variations:
opto mechatronics » opto mechatronic, _ optomechatronics, opto mechanics
etc mechatronics » c mechatronics, data mechatronics, 1 mechatronics
11 mechatronics » 1 mechatronics, a mechatronics, 11 mechanics
_ mechatronics » _ mechanics
26 robotics » 6 robotics, 26 robotic, 16 robotics
2 robotics » a robotics, 2 robotic, 6 robotics

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: %22control%((((2 robotics) OR (_ robotics))) OR (26 robotics))%((((11 mechatronics) OR (((etc mechatronics) OR (opto mechatronics))))) OR (_ mechatronics))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22control%((((2 robotics) or (_ robotics))) or (26 robotics))%((((11 mechatronics) or (((etc mechatronics) OR (opto mechatronics))))) or (_ mechatronics))%22".
• Adding a wildcard symbol may retrieve word variants: %22control%((((2 robotics) or (_ robotics))) or (26 robotics))%((((11 mechatronics) or (((etc mechatronics) OR (opto mechatronics))))) or (_ mechatronics))%22*.