This book covers the principles, methodology, and prototypes of sensing skin-like devices and related intelligence and software. Sensitive Skins are large-area and flexible arrays of sensors integrated onto the entire surface of machines. Sensitive Skin will endow these machines with the senses of proximity, touch, pressure, temperature, and chemical/biological agents, thus making possible the use of unsupervised machines in unstructured and unpredictable surroundings. Sensitive Skin will make machines "cautious" and thus friendly to their environment. It will revolutionize service industries, make important contributions to human prosthetics, and augment human sensing when fashioned into clothing. Being transducers producing massive data flow, Sensitive Skin devices will constitute yet another advance in the information revolution.