Biggest as in physically largest or the one that has taken the most time?
The biggest in size: we use a whole room to do the testing of the technology I’m designing right now to improve prosthetic limbs for amputees. We have cameras on all the walls to catch every angle of the motion of our participants.
The biggest in terms of time: we had to create a computer model of an aeroplane that would work at test it in the flight simulator.
I don’t know if you mean by size or by importance.
But every technology can have it’s own importance and value. but the one I’m working on currently I’m very proud of because there were many things that I had to get right in order to be able to make the test samples. I spent a lot of time coming up with design iterations, assess their feasibilities, and many modifications and research. So for me, this is my biggest one at the moment, but I’m sure there will be many more soon.