A robot's appearance and its way of interacting with humans is of fundamental importance. Until a few years ago there was a clear asymmetry between the typically excellent performance of industrial robots and their ugly and disharmonious bodies, with crude ways and potentially very dangerous movements

for the human environment. A modern artifact can be as harmonious and beautiful as a complex biological machine or a work of plastic art and thus it should be clear how design plays a key role for robot technology to become a part of our everyday life and change it essentially in a responsible and beneficial manner. It is designers who shape the interface between humans and machines and, as such, they will contribute to make robots as customizable and intuitively useful to inexperienced users according to a plug-and-play mode.

The new concept of robotronics as the mechatronics approach to designing advanced robots is the focus of the first chapter of the second book of the Robotics Goes MOOC project by Asfour et al. The main issues for robot manipulator design are covered in the subsequent material, namely redundant robots in Chapter 2 by Maciejewsky et al and parallel robots in Chapter 3 by Müller, where widely adopted kinematic solutions are presented. Then, the adoption to flexibilty, as opposed to the rigid mechanics paradigm, is discussed in Chapter 4 by Bertram et al with reference to elastic robots and in Chapter 5 by Laschi focused on soft robotics. Somewhat speculating on the previous two design solutions comes Chapter 6 by Cutkosky dealing with bioinspired robots. The last part of the book is devoted to robot locomotion, namely, Chapter 7 by Vendittelli on wheeled robots and Chapter 8 by Harada on (biped) humanoids.