Chopsticks are classics.
After all, they were invented 5000 years ago and their design - just two sticks! - has largely remained the same since then!
But do not let the simplicity fool you. The two sticks of the chopsticks are really a class-3 lever. Class-3 levers have the fulcrum at one end, and the force produced (on the load) at the other. The force applied (effort) is in the middle.
That chopsticks are a class-3 lever becomes clear in the video above. The thumb acts as the fulcrum and this is at one end. The fingers below the thumb apply the force/effort, and this causes the chopsticks at the other end to close in on any food that we intend to pick up,
When we use such a lever, the force we produce on the load is lower than the force/effort we apply. This gives us better control when using the chopsticks, especially when we pick up delicate food (e.g. egg yolk or tofu). Even if we apply more force, we will be less likely to crush the food.
Chopsticks are just one of the examples of Class-3 levers in the kitchen and in cooking. A pair of tongs is another (see above and read all about them in the 1-Minute NomNom "This will set your tongs wagging").
In fact, if we use children’s or training chopsticks, these come with a crimp at the top, and are really a modified pair of tongs!
photos: in order - depositiphotos/marcomayer; ab62; yuliang11; ribeiroantonio; newlight