Dielectric Elastomer Sensors with Advanced Designs and Their Applications

Abstract

Dielectric elastomer sensors (DESs) have been known as highly stretchable strain sensors for about two decades. They are composite films consisting of alternating dielectric and electrode layers. Their electrical capacitance between the electrodes is enhanced upon stretching. In this paper, a variety of advanced designs of DESs is introduced. An explanation of how these sensors work and how they perform in terms of capacitance versus deformation or load force is provided. Moreover, the paper describes how the sensor design affects the sensor characteristics in order to achieve a high measuring sensitivity. The most relevant quantities to be measured are distance variations or elongations, forces and pressure loads. It is demonstrated that the sensor design can be supported by Finite Element Method (FEM) simulations. In the second part of the paper, possible applications of the advanced DESs are outlined. Pure sensor applications to detect or monitor pressure or deformation are distinguished from other applications, where sensors form a part of a human–machine interface (HMI). DESs are predestined to be used in contact with the human body due to their softness and flexibility. In the case of an HMI, a dosed load on a sensor by the user’s hand enables the remote control of arbitrary technical functions. This can preferably be realized with an operating glove, which exhibits different categories of DESs. Possible applications of DESs are described with the support of functional demonstrators.

Keywords

• capacitive sensors
• dielectric elastomer
• strain sensors
• pressure sensors
• sensor design
• simulation