Sensors and actuators

 

Dielectric elastomers

Elastomer films, sensors and actuators

 

Ferro- and relaxor-ferroelectric polymers, electrets

Piezoelectric transducers, electrocaloric materials and space-charge electrets

 

Stretchable electrodes

Printable and stretchable electrodes and electrical contacts

 

Polymer and colloid synthesis

Synthesis of tailor-made polymers and surface modification with polymers

 

Polymer and surface characterization

Molar mass characterization, spectroscopy on polymers, layer thickness determination

 

 

Polymers for diffractive optics

Development of materials and holographic structuring

Your contact persons

Dielectric elastomers

 

We develop customized, electromechanical, dielectric elastomer actuators and sensors as films and multi-layer laminates and their integration according to different transducer concepts.

Services

 

  • development of dielectric elastomer actuators (DEA) and sensors (DES)
  • processing of dielectric elastomers (DE) as thin layers
  • development and processing of flexible electrodes
  • development of encapsulations for sensors and actuators

Actuators and sensors

 

  • DE-in-plane actuators
  • DE-out-of-plane actuators
  • laminates and stack actuators
  • elastomer sensor films
  • capacitive sensors
  • integration of actuators with optical elements

Characterization

 

  • actuator characteristics (deflections, forces, frequency-dependent)
  • breakdown field strengths at voltages up to 30 kV
  • dielectric resonance spectroscopy also under high voltage
  • mechanical properties (also under biaxial stretching)

Ferro- and relaxor-ferroelectric polymers, space-charge electrets

 

We process, functionalize and characterize customized electroactive polymers as well as space-charge electrets and find solutions for their integration into components.

Developments

 

  • piezoelectric polymers and composites as well as sensors and actuators
  • pyroelectric polymers and sensors
  • electrocaloric polymers, composites and laminates
  • cellular piezoelectric polymers (ferroelectrets)
  • space-charge electrets based on PP, PET, COP, PTFE and composites

Processing and functionalization

 

  • processing of e. g. PVDF, PVDF co- and terpolymers with adapted layer thicknesses from 100 nm to 300 µm
  • techniques: inkjet printing, electrospinning, melt-pressing, screen printing, doctor blade, spin-coating
  • processing of polymer films with cellular structures using voiding in supercritical CO2
  • electrical polarization and charging

Characterization

 

  • current-voltage and strain-voltage characteristics
  • piezoelectric properties (interferometric, acoustic, impact tests, frequency-dependent mechanical excitations)
  • dielectric resonance spectroscopy also under high voltage
  • surface potentials

Stretchable electrodes

 

Stretchable electrodes are developed, for example, for the construction of flexible sensors, actuators and transducers.

Developments

 

  • stretchable electrodes
  • ink formulations and printing processes for flexible and stretchable electrodes
  • electrical connections concepts
  • encapsulations for stretchable electrodes

Materials and processing

 

  • conductive particles in elastomer matrices
  • used particles: carbon black, carbon nanotubes, silver nanowires
  • semiconducting polymers such as PEDOT:PSS
  • application of electrodes using inkjet printing and dispensing

Characterization

 

  • mechanical properties (also under biaxial stretching)
  • electrical properties under stretching
  • layer thickness
  • adhesion

Polymer and colloid synthesis

 

We offer a multitude of synthesis competencies for water soluble and water dispersable polymers, and for surfaces and interfaces.

 

Synthesis

 

  • synthesis of special monomers
  • polymerisation in aqueous media
  • polymerisation in organic media
  • heterophase polymerization
  • suspension polymerization
  • emulsion polymerization
  • polymerization to obtain stimulus-responsive („smart“) materials

Controlled Radical Polymerization (CRP)

 

  • access to polymers with narrow molar mass distribution
  • block copolymers
  • standards for gel permeation chromatography

Surface
Modification

 

  • graft polymerization from surfaces
  • surface modification with functional polymers
  • chemical modification of polymers

Polymer and surface characterization

 

We characterize polymers, that are soluble in water or organic solvents, as well as dispersions and surfaces.

Gel permeation chromatography (GPC)

 

  • gel permeation chromatography (GPC) in organic media
  • GPC in aqueous madia (anionic, cationic and neutral analytes)
  • detection with static light scattering for the verification of the size exclusion method
  • tailor-made synthesis of calibration standards by CRP
  • „true“ molar mass values from GPC
  • molar mass range from ca. 0,5 to 200 kg·mol-1

Surface and particle analytics

  • particle analytics: dynamic light scattering (DLS)
  • surface analysis: contact angle measurement
  • film thickness determination: ellipsometry and profilometer, thickness ranges from nm to µm
  • dynamic processes (surface plasmon resonance)
  • spectroscopy, e. g. IR, UV-Vis,

Polymers for diffractive optics

 

Novel holographic polymers and composites are developed for the fabrication of diffractive optical thin-film elements through holographic micro- or nanostructuring of the material surface and volume.

Services

 

  • development of materials
  • testing of commercial materials
  • holographic irradiation with laser wavelengths: 355, 405, 488 and 532 nm
  • fabrication and characterization prototypes of optical elements

Materials and processing

 

  • azobenzene-containing materials
  • photopolymerizable organic and organic-inorganic composites
  • glassy and elastic polymers
  • photocrosslinkable LC polymers
  • optimized irradiation procedure and all-optical manufacturing processes

Holographic elements

 

  • solid, flexible, electrically switchable, stretchable, functional layers
  • surface relief gratings
  • volume gratings
  • polarization gratings
  • prototypes of diffractive optical elements
  • replication methods

Your contact persons

Michael Wegener

Contact Press / Media

Dr. Michael Wegener

Head of Department | Sensors and Actuators

Fraunhofer IAP
Geiselbergstraße 69
14476 Potsdam

Phone +49 331 568-1209

Erik Wischerhoff

Contact Press / Media

Dr. Erik Wischerhoff

Contact Person | Polymer Synthesis and Characterization

Fraunhofer IAP
Geiselbergstraße 69
14476 Potsdam

Phone +49 331 568-1508

Oksana Sakhno

Contact Press / Media

Dr. Oksana Sakhno

Contact Person | Holographic Structuring

Fraunhofer IAP
Geiselbergstraße 69
14476 Potsdam

Phone +49 331 568-1247

Daniel Pinkal

Contact Press / Media

Daniel Pinkal

Contact Person | Sensors and Actuators

Fraunhofer IAP
Geiselbergstraße 69
14476 Potsdam

Phone +49 331 568-1916

Alexander Oehrl

Contact Press / Media

Dr. Alexander Oehrl

Contact Person | Polymer Synthesis and Characterization

Fraunhofer IAP
Geiselbergstraße 69
14476 Potsdam

Phone +49 331 568-1917