So robots come in all different shapes and sizes, some are huge, and some are tiny, but the thing that they all have in common is that a robot has to be built by someone/something. It has to be assembled. Generally, a robot is created to perform a specific function, but in this modern age, as robots continue to evolve, so do the tasks they're required to perform. So one of the big advancements in robotic science is the notion of 'self-assembling' robots. Robots that are made up of smaller building blocks that can re-arrange themselves to create different shapes and machines.
Whilst we're a little way off having a miniature transformer for a mobile phone, researchers are getting closer to multifunctional robots that can assemble themselves in different ways according to the task they're required to carry out. Check out this awesome swarm of miniature robots which are incredibly simple and work together to create complex shapes that would otherwise be impossible for a single unit to create.