Lightweight design is a very important topic in many engineering fields: automotive industry, aeronautics, machine tools, robot arms, civil engineering, architecture, ...
Optimization techniques are applied in the design of structures in order to obtain an efficient solution in terms of weight, cost or performance. The three structural optimization types are: Sizing, Shape and Topology Optimization.
In a Topology Optimization, the objective is to minimize a function taking into account some constraints. For example, the objective may be to minimize the compliance (i.e. maximize the stiffness) while a constraint is applied on the volume. By doing so, the volume of the structure will be reduced while maintaining the maximum level of stiffness possible.
That allows you to create super lightweight components like this one: