Preface

When subjected to the microwave irradiation, the molecules in materials begin to oscillate, thereby generating heat. What began as a by-product of the radar technology developed during World War II, microwave heating has found wide applications ranging from the microwave ovens in a kitchen to heat food, to a sterilization apparatus for medical treatment, to materials processing in the various industries. In these applications, microwave heating demonstrates significant advantages over conventional methods in reduced process time and less environmental impacts due to a fast, homogeneous, selective and non-thermal heating effect process. It triggers research enthusiasm from all over the world. Currently, microwave heating has been expanded to include such fields as chemical-, agricultural-, forestry- and the mineral processing industry, etc. This book provides readers a general concept and the current progress of microwave heating in several major areas distributed in each chapter. Further, some specific new applications of microwave heating are introduced to cover both the basic application and advanced aspects as well.

Several microwave cooking operations, particularly the relationship between food flavour and microwave heating have been intensively discussed at the beginning of this book. This is very interesting and attractive when cooking with microwave. The great potential of microwave heating in the agricultural, forestry, and mineral processing industries has been presented due to its reduced energy consumption, decreased environmental impacts, and simplified processing, which has attracted much attention in recent years. Some new applications of microwave heating have been developed to wide its way. As an example it has been used to heat microfluidic devices due to its preferential heating capability and non-contact delivery of energy, in which the microwave energy can be directly delivered to the microfluid sample with faster heating and cooling rates. Localized microwave dielectric heating of fluids at micrometer scale geometry, through the use of integrated planar microwave transmission line as a power source, has also been presented.

The research and applications on microwave heating have developed so quickly over the last several decades and many works have been published. It is necessary but difficult to collect the broad range of scientific knowledge in this field comprehensively which can be used as the reference for the followed research. The entrustment of this important work to the collaboration of the chapter contributors,

#### XII Preface

whose opinions are believed to be the best in their individual fields, is the reliable and easiest way. This book is comprised of 8 chapters within 3 sections. Chapters 1-4, [Part 1] are devoted to the general concept and applications in microwave heating. Chapters 5-6 [Part 2] are the development of microwave heating technology. While those of Chapters 7-8 [Part 3] are focused on the new applications of microwave heating.

Finally, I gratefully acknowledge all the authors for their valuable and dedicated effort in preparing their reputed contributions.

> **Wenbin Cao**  University of Science and Technology Beijing, Beijing, P. R. China

**Section 1** 
