Introduction

Abstract

A typical technical field had evolved from infancy through the efforts of a number of researchers. As the evolution progresses, a consensus on the scope of the field and the fundamental definitions of associated objects or parameters emerge. When the technical area is dominated by a single major discipline, such as mechanical engineering or physics, the consensus on definitions and scope can be achieved quite rapidly. However, when the emerging technical area is truly multidisciplinary, as is the case with the technical field of transduction, then the consensus can be difficult to forge. Indeed, the field of transduction has involved virtually all of the major technical disciplines, each having its own perspective on the fundamental definition of a transducer. As a result there are many different definitions of transducers in use. The most common of these definitions are included in what follows:

• 1 A transducer is a device which transforms nonelectrical energy into electrical energy or vice versa. (See, e.g., Middlehoek and Hoogerwerf [1].)

• 2 A transducer is a device which transforms energy from one domain into another. (See for example Rosenberg and Karnopp [2].) Typical energy domains are mechanical, electrical, chemical, fluid, and thermal.

• 3 A transducer is a device which transforms energy from one type to another, even if both energy types are in the same domain. (See Busch-Vishniac [3] for instance.)