Integrated Sensor Concepts for Dielectric Elastomer Actuators

Maas, Jürgen; Griese, Martin; Hoffstadt, Thorben

doi:10.1115/smasis2013-3243

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The output current was captured using instrumentation amplifiers and filtered with 2nd order Butterworth low-pass filters to remove noise outside of the frequency range. Once sampled back in LabVIEW, a fast Fourier transform (FFT) procedure decoupled the frequency components and calculated the respective capacitance at each frequency using a gain and phase shift method [32,33].…”

Section: Methodsmentioning

confidence: 99%

Stretch not flex: programmable rubber keyboard

Tairych

Anderson

2015

Smart Mater. Struct.

View full text Add to dashboard Cite

Stretchability is a property that brings versatility and design freedom to human interface devices. We present a soft, flexible and stretchable keyboard made from a dielectric elastomer sensor sheet. Using a multi-frequency capacitance sensing technique based on a transmission line model, we demonstrate how this keyboard can detect touch in two dimensions, programmable to increase the number of keys and into different layouts, all without adding any new wires, connections or modifying the hardware. The method is efficient and scalable for large sensing systems with multiple degrees of freedom.

show abstract

Section: Methodsmentioning

confidence: 99%

Stretch not flex: programmable rubber keyboard

Tairych

Anderson

2015

Smart Mater. Struct.

View full text Add to dashboard Cite

show abstract

“…Since the material parameters of the DEAP, like the permittivity ε r or the conductivity σ p , depend on, among other things, the applied voltage and operation frequency [9], these concepts have the big advantage that the applied voltage and frequency used for the identification can be kept constant in a certain range, so the material parameters vary only on the stretch. Different integration concepts for realizing sensor-based concepts as well as suggestions as regards how to evaluate these sensors are presented by Maas et al [10].…”

Section: Integrated Sensor Concepts Versus Self-sensingmentioning

confidence: 99%

“…General drawbacks of a sensor-based concept from the whole appli-cationʼs point of view are the additional sensor films required that affect the mechanical behavior of the whole actuator, as well as the increased processing effort needed to integrate those sensor films. On the other hand, the additional films ensure galvanic isolation [10].…”

Section: Sensor-based Conceptsmentioning

confidence: 99%

Online identification algorithms for integrated dielectric electroactive polymer sensors and self-sensing concepts

Hoffstadt¹,

Griese²,

Maas³

2014

Smart Mater. Struct.

View full text Add to dashboard Cite

Transducers based on dielectric electroactive polymers (DEAP) use electrostatic pressure to convert electric energy into strain energy or vice versa. Besides this, they are also designed for sensor applications in monitoring the actual stretch state on the basis of the deformation dependent capacitive-resistive behavior of the DEAP. In order to enable an efficient and proper closed loop control operation of these transducers, e.g. in positioning or energy harvesting applications, on the one hand, sensors based on DEAP material can be integrated into the transducers and evaluated externally, and on the other hand, the transducer itself can be used as a sensor, also in terms of self-sensing. For this purpose the characteristic electrical behavior of the transducer has to be evaluated in order to determine the mechanical state. Also, adequate online identification algorithms with sufficient accuracy and dynamics are required, independent from the sensor concept utilized, in order to determine the electrical DEAP parameters in real time. Therefore, in this contribution, algorithms are developed in the frequency domain for identifications of the capacitance as well as the electrode and polymer resistance of a DEAP, which are validated by measurements. These algorithms are designed for self-sensing applications, especially if the power electronics utilized is operated at a constant switching frequency, and parasitic harmonic oscillations are induced besides the desired DC value. These oscillations can be used for the online identification, so an additional superimposed excitation is no longer necessary. For this purpose a dual active bridge (DAB) is introduced to drive the DEAP transducer. The capabilities of the real-time identification algorithm in combination with the DAB are presented in detail and discussed, finally.

show abstract

“…However, up to now all forms of geometric sensing for DEs have been limited to measuring its bulk parameters such as length or area 10,11 . No information regarding local deformation within the DE has ever been measured.…”

Section: Introductionmentioning

confidence: 99%

Localised strain sensing of dielectric elastomers in a stretchable soft-touch musical keyboard

Tairych

Anderson

2015

SPIE Proceedings

View full text Add to dashboard Cite

We present a new sensing method that can measure the strain at different locations in a dielectric elastomer. The method uses multiple sensing frequencies to target different regions of the same dielectric elastomer to simultaneously detect position and pressure using only a single pair of connections. The dielectric elastomer is modelled as an RC transmission line and its internal voltage and current distribution used to determine localised capacitance changes resulting from contact and pressure.This sensing method greatly simplifies high degree of freedom systems and does not require any modifications to the dielectric elastomer or sensing hardware. It is demonstrated on a multi-touch musical keyboard made from a single low cost carbon-based dielectric elastomer with 4 distinct musical tones mapped along a length of 0.1m. Loudness was controlled by the amount of pressure applied to each of these 4 positions.

show abstract

Integrated Sensor Concepts for Dielectric Elastomer Actuators

Cited by 4 publications

References 0 publications

Stretch not flex: programmable rubber keyboard

Stretch not flex: programmable rubber keyboard

Online identification algorithms for integrated dielectric electroactive polymer sensors and self-sensing concepts

Localised strain sensing of dielectric elastomers in a stretchable soft-touch musical keyboard

Contact Info

Product

Resources

About