Friedrich Pfeiffer & Teresa Zielinska 
Walking: Biological and Technological Aspects [PDF ebook] 

The book describes the results of research into the living world, which were conducted in such a way as to provide inspiration to engineering design of walking machines. The biological topics are presented in a form that is intelligible to engineers and can be applied in the design of mechanical devices. The text also introduces the design problems that are encountered during prototyping of specific robots. This information provides insight to biologists interested in basic physical properties of locomotion.