I saw a video of a researcher who made pliers out of injection molded plastic as a single part. The design used thin and flexible sections to allow bending and movement on purpose in order to produce the grip and force seen in regular pliers. I tried my hand at modeling and simulating a pair of "nail clippers." They are very ugly and I'm sure they would not work well, but it was interesting!

Designing them in Fusion 360 allowed me to use their cloud simulation to conduct an FEA test on the clippers. This model was designed in twenty minutes. It is very simplistic and not aesthetic in any way, it was more of a curious test.

Below you can see a side view model along with a gif of the deformation of the clippers. These would obviously fail over time from fatigue in the thin sections, but the maximum stress and strain stayed well within the elastic region of the material and below the yield strength.