Adaptronics

Janocha, Hartmut, ed. Adaptronics and Smart Structures Basics, Materials, Design, and Applications. New York Springer, 1999. 

Adaptronics Smart materials Smart stmcture Unconventional actuator... 

Denkena B, Will JC, SeUmeier V (2006) Prediction of process stability and dynamic forces of an adaptronic spindle system, Conf.-Speech, Adaptronic Congress... 

Janocha H (2007) Adaptronics and smart structirres basics, materials, design, and applications. Springer. Berlin... 

The term adaptronics designates a system (and its development process) wherein all functional elements of a conventional regulator circuit are existent and at least one element is applied in a multifunctional way. The conformity... 

An adaptronic system thus is characterized by adaptability and multifunctionality. The aim is to combine the greatest possible number of application-specific functions in one single element and, if appropriate, in one specific material (see Fig. 1.1). 

Fig. 1.1. Transition from a a conventional system to b an adaptronic system...

Examples for adaptronic systems with a more distinct visionary character are window panes whose transparency automatically regulates itself or can be adjusted within seconds by pressing a button and hydroplanes whose aerodjmamic profile adapts itself to the prevailing flight conditions. 

The example of an adaptronic shock absorber shows how the electrorhe-ological fluid is simultaneously used as a classic absorber fluid and as an actuator (if necessary, additionally as a sensor). This use is made possible by the capacity of such fluids to change their viscosity to a vast extent in less than a second when they are influenced by an electric field. 

Functional qualities can, however, only be used in terms of adaptronics if there is success in combining the specific release phenomena with the respective desired functions. What is therefore required in the conception of multifunctional elements (level II) is the release and specific use of the material-inherent options. For this purpose it is necessary to make use of release phenomena of a physical, chemical or biological nature on material in such a way that, as necessary, several effects can be combined by taking well-directed action. For example, the application of electrorheological fluids... 

The system level - in the present example the entire motor vehicle -calls for the need to conceptualize during the creation of the adaptronic structure. For instance, the structural shape and damping characteristic of a shock absorber must harmonize with the overall design of a moving gear. Here again, the aim is to optimize the functionality of the entire system. 

Functional materials constitute the essential basis of all adaptronic systems. The made-to-measure production of functional materials, wherein several functions are interlinked at a molecular level, is therefore of special importance. The more application-specific functions are combined in one single element, the bigger is the advantage in terms of an adaptronic system optimization. Multifunctionality can, however, not be a characteristic feature of an isolated element, but should always manifest itself by meeting user-specific requirements within a system interrelationships. Thus the same element can produce a decisive compression of functions in a given case (A), while it can be completely worthless in a given case (B). 

Materials represent the essential basis for all multifunctional effects. The conception of multifunctional elements is therefore mainly based on the made-to-measure production of functional materials, wherein several functions are interlinked at a molecular level. However, the fact that this is not sufficient in all cases is clearly shown by taking adaptronic shock absorbers as an example, because some effects can only be produced if several materials are combined in suitable interconnected layers or other compounds. 

The foregoing explanations show that a basis for adaptronic structures is created in numerous different disciplines of science. The range of applications covers various physical, but also chemical and biological technologies... 

The scope of the application of adaptronic structures or systems can be restricted as the spectrum of influential scientific disciplines. Almost each scientific field covers applications, whose technical benefit and business management utility can be improved by realizing adaptronic concepts. While the need for efficient multifunctional materials certainly originates in the high-technology area, the scope of application is by no means exclusively confined to this field. For example, multifunctional adjusting elements of shape memory alloys are successfully applied for the automatic control of ventilation flaps in greenhouses. 

However, even products resulting from highly specialized materials are only partially needed for the realization of efficient adaptronic concepts. Simple adaptive systems, with a minimal number of elements in motion, are of special importance in a surrounding field, where the protection against shortfalls is a decisive factor and where little or no well-trained staff are available for the removal of technically complex problems. The broad range of applications covers a number of areas where adaptronic concepts have been intensively pursued and partially have already been translated into concrete action. The specific interest shown in a particular line of business is a result... 

Adaptronics as an overall concept for the development of adaptronic structures and systems is still a young discipline, which was only able to establish itself a few years ago. On the other hand, the research in the fields of multifunctional materials and multifunctional elements, which are the basic elements of adaptronics, started much earlier. The origins of adaptronics under a different name - go back to the early 1980s. Early progress came from the arms research sector, especially from various air forces. 

In 1992, the first govermnent funded projects were incorporated by the German Ministry of Research and Technology in its material research program. These projects initially concentrated on the improvement of pure material functions. However, it quickly proved necessary to enlarge the basic area of materials and to develop integrated concepts for multifunctional adaptive structures or systems in terms of adaptronics. In this context the objective was the application-orientated optimization of functional materials and their functional integration in a system. 

In November 1994 a further expert workshop took place in Diisseldorf, on the occasion of which some of the main subjects within the broad and interdisciplinary field of adaptronics were thoroughly analysed. In the experts opinion during that workshop, the greatest application potential could be... 

The aim for the future, apart from the promotion of individual pilot projects, is the further state-supported advancement of specific areas of adaptronics, which are marked by significant high-technology and application potential. 

Fig. 2.1. The bio-inspired approach to adaptronic structures a active materials, b induced-strain actuators, c integrated active sensors d multifunctional composites, e microcontrollers...

---