Conventional actuator

Conventional actuator applications, and the potential advantages gained by replacing existing technologies with DEA, are given in Table 10.6. 

Miniaturized conventional actuators have to be glued or mechanically assembled on the microfabricatied valve or pump structure. 

The general features of the miniaturized conventional actuators and the micromachinable actuators are listed in Table 1. 

Table 1. Features of the miniaturised conventional actuators and the micromachinable actuators [1]...

Actuators can be classified as conventional and unconventional actuators. Conventional actuators are commonly used as essential components for mechatronic systems (see Pig. 1 (left)). These are, for instance, electrical motors, pneumatic actuators, hydraulic pistons, or relays. 

It is obvious that certain actuating properties of transducer materials are far beyond the ones of conventional actuating principles. This enables to use them in special application areas such as lightweight construction, active vibration control, or the development of highly dynamic systems for instance. 

Conventional actuators also suffer from relatively large footprint and this large size limits the degree of miniaturization and actuator densities that can be achieved. In contrast, arrays of polymer thermal actuators [108] have been fabricated that have a high actuator density and can be used to exploit parallel arrangements, such as for the handling of large objects. 

The concepts of intelligent and self-sensing actuators mentioned in Sect. 6.1.2 are exemplified below with solid-state actuators. The potential of both concepts is especially easy to recognize and to compare when described in terms of system theory. We will start with the conventional actuator. 

Fig. 6.6. Conventional actuator (fcv transfer factor of the power amplifier)...

Substitution of conventional actuators by use of smart materials Reduced complexity, increased reliability, weight reduction... 

There are two directions of machines with actively deformable materials. One is to replace conventional actuators to muscle-like bundles that shrink or stretch. Another direction is to build machine with distributed muscle like structures. The latter is not an extension of conventional machines, and requires methodology to solve major problems. The latter direction is focused on in this study. 

Another consideration is the small size of the objects that it is wished to move or manipulate, for which miniaturization of conventional actuators is not going to be possible. For instance, insect-size robots that can fly, hop and crawl are one example of systems that cannot be built with conventional actuators. Fabrication paradigms and driving principles prevent conventional drives from being scaled down further. 

Konyo et al. developed the tactile display using the IPMC actuator (Konyo et al. 2007). The IPMC actuator has many advantages including high spatial resolution, wide frequency range, an ability of generate stimuli in multiple directions, wearabiUty, and safety, as compared to the conventional actuators used for die... 

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