Preface

In the last few decades, much effort has been directed towards the development of mechatronic devices capable of interacting safely and effectively with unstructured environments and humans. On one hand, these research activities highlighted the limits of traditional sensorymotor technologies in terms of flexibility and responsiveness to ever changing scenarios. On the other hand, the fascinating world of *smart structures and materials*, which is somehow the most natural engineering answer to the challenge of adaptability, is still far from meeting strict industrial requirements such as reliability, damage-tolerance, ease-of-usage and cost-effectiveness. In particular, even if it is possible to envisage futuristic solid-state machines with unconventional morphing shapes, it would be too presumptuous to say that every *smart* devices have already transitioned from basic research to practically useful and well-engineered products.

Trivially speaking, a device might be called *smart* if it can sense and respond to the surrounding environment in a predictable and useful manner via the integration of an actuation system, a network of proprioceptive and exteroceptive sensors, and a suitable controller. Such devices, possibly powered with a minimum amount of energy, usually include one or more *smart materials* which exhibit some coupling between multiple physical domains (e.g. piezoelectric materials, shape memory alloys, magento/electro rheological fluids). There are instances where the breakthrough from proof-of-concept laboratory rigs into commercial applications has already seen the light. For example, piezo-actuators and sensors are state-of-the-art technology. In the same way, shape-memory-alloys are widely used in many biomedical applications. In other cases, such as magneto/electro-active polymer actuators and generators, the technology is rather new and its potential may not be fully exploited at the current level of knowledge.

Regardless of the aforementioned considerations, the effort towards the technical maturity of any *smart* device requires the combined action of different research fields ranging from material science, mechanical and electrical engineering, chemistry and physics. Hence, it is strongly believed that the tremendous growth of research and industrial projects concerning *smart* systems in the last 20 years has been principally due to the synergistic cooperation of universities, government institutions and industries and to the birth of under- and post-graduate courses where a multidisciplinary approach is now a *de-facto* standard.

Therefore, if a path towards the future has been traced and if interdisciplinarity is the key to success, it is surely valuable to combine researchers and scientists from different fields into a single virtual room. That is indeed the objective of the present book, which tries to summarize in an edited format and in a fairly comprehensive manner, many of the recent technical research accomplishments in the area of *Smart Actuators* and *Smart Sensors*. Current and future challenges for the optimal design, modelling, control and technological implementation of the next-generation adaptive mechatronic systems are treated with the objective to provide a reference point on the current stateof-the-art, to propose future research activities and to stimulate new ideas. As long as the authorship is taken from disparate disciplines, the book hopefully reflects the multicultural nature of the field and will allow the reader to taste and appreciate different points of view, different engineering methods and different tools that must be jointly considered when designing and realizing *smart actuation and sensing systems*.

#### **Giovanni Berselli, Ph.D.**

Interdepartmental Center INTERMECH Mo.Re. DIEF – "Enzo Ferrari" Engineering Department University of Modena and Reggio Emilia Modena, Italy

**Section 1** 
