Prof. Anne Ladegaard Skov Profile

Dielectric elastomer actuators (DEAs) are usually operated at high voltage to induce sufficient electric pressure between two compliant electrodes sandwiching the dielectric elastomer. However, a harsh environment (e.g. humid environment combined with high voltage) often induces electrical breakdown (EB) of the DEAs, which results in pinhole formation or even tearing of the device, followed by macroscopic failure. Therefore, it is ideal for DEAs to be self-healing to extend robustness and lifetime, such as observed for biological muscles, which can be healed from injuries by inherent biological processes. Herein, we prepared a soft (Young’s modulus: 187 kPa) polydimethylsiloxane (PDMS) thermoplastic elastomer (TPE) to demonstrate an autonomous self-healing ability. The system exploits hydrogen bonding (H-bonding) in two types of transient cross-linkers: urea group serves as a sacrificial bond under loading and ureidopyrimidone (UPy) serves as a strong, load-carrying crosslinker. The PDMS TPE shows a crossover of the elastic moduli at 119 °C and highly frequency dependent elastic modulus. The DEA is prepared with compliant, corrugated silver electrodes on both sides of a corrugated PDMS TPE film. A maximum actuation strain (6.8 % in longitudinal direction) is achieved at 18.8 V μm-1. A further increase in potential does not increase the actuation strain, but EBs are observed on the electrodes and the actuation is maintained without any detrimental effects to the film despite the previous breakdown. The EBs do not form permanent pinholes, nor do they cause tearing of films. Instead, only the removal of the silver electrode is observed, which is the so-called self-clearing effect commonly observed for metallic electrodes. In combination with the self-clearing effect, the heat generated by the EBs allows the PDMS TPE to soften. The polymer molecules are then capable of flowing into the voids that were created at the initiation of the EBs. As a result, further propagation of the EB is hindered, and instead, an instantaneous and autonomous self-healing of the DEA is observed.

Proceedings Article | 22 March 2021 Presentation

Detection of biofouling via surface instabilities of dielectric elastomer

Sara Krpovic, Kim Dam-Johansen, Anne Ladegaard Skov, Samuel Rosset, Iain Anderson

Proceedings Volume 11587, 1158707 (2021) https://doi.org/10.1117/12.2584717

KEYWORDS: Capacitance, Silicon, Dielectrics, Sensors, Oceanography, Metals, Electrodes, Microscopes, Copper

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Proceedings Article | 22 March 2021 Presentation + Paper

Super-stretchable silicone elastomer applied in low voltage actuators

Pengpeng Hu, Jeppe Madsen, Anne Ladegaard Skov

Proceedings Volume 11587, 1158715 (2021) https://doi.org/10.1117/12.2581476

KEYWORDS: Dielectric elastomer actuators, Silicon, Polymers, Polymeric actuators, Electrical breakdown, Dielectrics

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Proceedings Article | 22 March 2021 Presentation + Paper

High-permittivity silicone dielectric elastomers compatible with ionic liquid-grafted chloropropyl-silicone oil

Zhaoqing Kang, Liyun Yu, Yi Nie, Suojiang Zhang, Anne Ladegaard Skov

Proceedings Volume 11587, 1158714 (2021) https://doi.org/10.1117/12.2581427

KEYWORDS: Silicon, Dielectrics, Liquids, Chemical compounds, Artificial muscles, Actuators

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Proceedings Article | 22 March 2021 Presentation + Paper

Frequency dependent behavior of silicone slide-ring elastomers

Jakob-Anhtu Tran, Jeppe Madsen, Anne Ladegaard Skov

Proceedings Volume 11587, 1158716 (2021) https://doi.org/10.1117/12.2581744

KEYWORDS: Silicon, Transducers, Supramolecular assemblies, Molecular self-assembly, Dielectrics

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Proceedings Article | 24 April 2020 Presentation + Paper

Soft silicone elastomers with no chemical cross-linking and unprecedented softness and stability

Pengpeng Hu, Qian Huang, Jeppe Madsen, Anne Ladegaard Skov

Proceedings Volume 11375, 1137517 (2020) https://doi.org/10.1117/12.2557003

KEYWORDS: Silicon, Polymers, Affine motion model, Data modeling, Dielectrics, Platinum, Actuators, Statistical analysis, Robotics, Tissues

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Proceedings Article | 24 April 2020 Presentation

Highly stretchable and conductive fiber wires based on aligned carbon nanotubes (Conference Presentation)

Jiang Shao, Anders Daugaard, Anne Skov

Proceedings Volume 11375, 113752M (2020) https://doi.org/10.1117/12.2566364

KEYWORDS: Carbon nanotubes, Electronics, Chemical engineering, Polymers, Nanocomposites, Light emitting diodes, Power supplies

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Proceedings Article | 22 April 2020 Presentation + Paper

Novel silicone-ionic liquid composite with keratin utilized as pressure sensor

Xue Liu, Yi Nie, Liyun Yu, Suojiang Zhang, Anne Ladegaard Skov

Proceedings Volume 11375, 113750R (2020) https://doi.org/10.1117/12.2558412

KEYWORDS: Sensors, Liquids, Composites, Dielectrics, Silicon, FT-IR spectroscopy, Scanning electron microscopy, Polymers, Polymeric sensors, Industrial chemicals

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Proceedings Article | 22 April 2020 Presentation + Paper

Active deformation of dielectric elastomer for detection of biofouling

Sara Krpovic, Kim Dam-Johansen, Anne Ladegaard Skov, Samuel Rosset, Iain Anderson

Proceedings Volume 11375, 1137521 (2020) https://doi.org/10.1117/12.2558402

KEYWORDS: Silicon, Sensors, Capacitance, Electrodes, Dielectrics, Metals, Capacitors, Oceanography

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Proceedings Article | 22 April 2020 Presentation + Paper

Utilizing slide-ring cross-linkers in polysiloxane networks for softer dielectric elastomer actuators

Jakob-Anhtu Tran, Jeppe Madsen, Anne Ladegaard Skov

Proceedings Volume 11375, 1137518 (2020) https://doi.org/10.1117/12.2557355

KEYWORDS: Polymers, Dielectric elastomer actuators

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Proceedings Article | 22 April 2020 Presentation

Insight into the dielectric breakdown of elastomers (Conference Presentation)

Justina Vaicekauskaite, Liyun Yu, Anne Ladegaard Skov

Proceedings Volume 11375, 113751G (2020) https://doi.org/10.1117/12.2557792

KEYWORDS: Dielectric breakdown, Dielectrics, Electrodes, Robotics, Actuators, Silicon, Metals, High speed cameras

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Proceedings Article | 13 March 2019 Presentation + Paper

Silicone elastomer map: design the ideal elastomer

Justina Vaicekauskaite, Piotr Mazurek, Sindhu Vudayagiri, Anne Ladegaard Skov

Proceedings Volume 10966, 1096625 (2019) https://doi.org/10.1117/12.2515305

KEYWORDS: Silicon, Dielectrics, Sensors, Transducers, Stretchable circuits, Polymers, Electronics, Biomedical optics, Skin, Transmittance

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Proceedings Article | 13 March 2019 Presentation + Paper

Design of reliable silicone elastomers for dielectric elastomers and stretchable electronics

Piotr Mazurek, Sindhu Vudayagiri, Anne Skov

Proceedings Volume 10966, 109660M (2019) https://doi.org/10.1117/12.2515307

KEYWORDS: Silicon, Polymers, Dielectrics, Particles, Stretchable circuits, Silica, Adhesives, Chemistry, Network architectures

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Proceedings Article | 17 April 2017 Paper

Electrical breakdown phenomena of dielectric elastomers

Ramona Mateiu, Liyun Yu, Anne Skov

Proceedings Volume 10163, 1016328 (2017) https://doi.org/10.1117/12.2258719

KEYWORDS: Dielectrics, Silicon, Electrical breakdown, Polymers, Cobalt, Scanning electron microscopy, Solids, Reliability, Silver, Chemical analysis

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Proceedings Article | 1 April 2015 Paper

Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on tunable functionalized copolymers

Frederikke Madsen, Liyun Yu, Anders Daugaard, Søren Hvilsted, Anne Skov

Proceedings Volume 9430, 943012 (2015) https://doi.org/10.1117/12.2082952

KEYWORDS: Dielectrics, Silicon, Molecules, Dielectric breakdown, Electrical breakdown, Particles, Polymers, FT-IR spectroscopy, Silica, Temperature metrology

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Proceedings Article | 1 April 2015 Paper

Super soft silicone elastomers with high dielectric permittivity

Frederikke Madsen, Liyun Yu, Søren Hvilsted, Anne Skov

Proceedings Volume 9430, 94301D (2015) https://doi.org/10.1117/12.2082929

KEYWORDS: Silicon, Dielectrics, Polymers, Dielectric breakdown, Particles, Electrical breakdown, Matrices, Silica, Composites, Titanium dioxide

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Proceedings Article | 1 April 2015 Paper

High energy density interpenetrating networks from ionic networks and silicone

Liyun Yu, Frederikke Madsen, Søren Hvilsted, Anne Skov

Proceedings Volume 9430, 94300T (2015) https://doi.org/10.1117/12.2082917

KEYWORDS: Silicon, Silica, Dielectrics, Particles, Electrical breakdown, Polymers, Dielectric breakdown, Electrodes, Actuators, Head

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Proceedings Article | 8 March 2014 Paper

Filled liquid silicone rubbers: possibilities and challenges

Liyun Yu, Sindhu Vudayagiri, Shamsul Zakaria, Mohamed Benslimane, Anne Skov

Proceedings Volume 9056, 90560S (2014) https://doi.org/10.1117/12.2044565

KEYWORDS: Composites, Silicon, Dielectrics, Coating, Electrical breakdown, Liquids, Particles, Lawrencium, Polymers, Titanium dioxide

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Proceedings Article | 8 March 2014 Paper

The electrical breakdown of thin dielectric elastomers: thermal effects

Shamsul Zakaria, Peter Morshuis, Mohamed Benslimane, Krist Gernaey, Anne Skov

Proceedings Volume 9056, 90562V (2014) https://doi.org/10.1117/12.2037292

KEYWORDS: Dielectrics, Electrical breakdown, Polymers, Data modeling, Electrodes, Thermal effects, Thin films, Silica, Numerical analysis, Platinum

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Proceedings Article | 8 March 2014 Paper

Soft silicone based interpenetrating networks as materials for actuators

Liyun Yu, Lidia Gonzalez, Søren Hvilsted, Anne Skov

Proceedings Volume 9056, 90560C (2014) https://doi.org/10.1117/12.2044769

KEYWORDS: Silicon, Silica, Dielectrics, Absorption, Actuators, Chemistry, FT-IR spectroscopy, Polymers, Electroactive polymers, Particles

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Proceedings Article | 8 March 2014 Paper

Novel encapsulation technique for incorporation of high permittivity fillers into silicone elastomers

Piotr Mazurek, Søren Hvilsted, Anne Skov

Proceedings Volume 9056, 90562T (2014) https://doi.org/10.1117/12.2044778

KEYWORDS: Dielectrics, Silicon, Microfluidics, Composites, Liquids, Polymers, Electroactive polymers, Bioalcohols, Molecules, Sodium

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