A Dielectric Elastomer-Based Multimodal Capacitive Sensor

Dielectric elastomer (DE) sensors have been widely used in a wide variety of applications, such as in robotic hands, wearable sensors, rehabilitation devices, etc. A unique dielectric elastomer-based multimodal capacitive sensor has been developed to quantify the pressure and the location of any touch simultaneously. This multimodal sensor is a soft, flexible, and stretchable dielectric elastomer (DE) capacitive pressure mat that is composed of a multi-layer soft and stretchy DE sensor. The top layer measures the applied pressure, while the underlying sensor array enables location identification. The sensor is placed on a passive elastomeric substrate in order to increase deformation and optimize the sensor’s sensitivity. This DE multimodal capacitive sensor, with pressure and localization capability, paves the way for further development with potential applications in bio-mechatronics technology and other humanoid devices. The sensor design could be useful for robotic and other applications, such as fruit picking or as a bio-instrument for the diabetic insole.

Thermo-Electro-Mechanical Characterization of PDMS-Based Dielectric Elastomer Actuators

The present contribution aims towards a thermo-electro-mechanical characterization of dielectric elastomer actuators (DEA) based on polydimethylsiloxane (PDMS). To this end, an experimental setup is proposed in order to evaluate the PDMS-based DEA behavior under the influence of various rates of mechanical loading, different ambient temperatures, and varying values of an applied electric voltage. To obtain mechanical, electro-mechanical and thermo-mechanical experimental data, the passive behavior of the material, as well as the material’s response when electrically activated, was tested. The influence of the solid electrode on the dielectric layer’s surface was also examined. Moreover, this work focuses on the production of such DEA, the experimental setup and the interpretation and evaluation of the obtained mechanical hysteresis loops. Finite element modeling approaches were used in order to model the passive and the electro-mechanically active response of the material. A comparison between experimental and simulation results was performed.

Comparison of How Graphite and Shungite Affect Thermal, Mechanical, and Dielectric Properties of Dielectric Elastomer-Based Composites

The aim of this work involved comparing the effect graphite and shungite have on the properties of dielectric elastomer-based materials. For this reason, dielectric elastomer–Sylgard (S) was filled with 1, 3, 5, 10, and 15 wt.% of graphite (G) and shungite (Sh). The structure of the obtained materials was studied by means of scanning electron microscopy and atomic force microscopy. The influence of the introduced additives on the thermal stability of the obtained composites was evaluated using thermogravimetry. Moreover, the mechanical properties and the dielectric constant of the elastomer with an addition of graphite and shungite were determined. Obtained results allowed us to establish that the presence of graphite as well as shungite significantly influences mechanical as well as dielectric properties. Additionally, the optimum mass of additives, allowing to increase the dielectric constant without the significant decrease of strain at break, was indicated. In the case of materials containing graphite, regardless of the filler content (1–15 wt.%), the mechanical as well as the dielectric properties are improved, while in the case of composites with an addition of shungite exceeding the 5 wt.% of filler content, a reduced tensile strength was observed.