Elecroceramic-polymer composites for sensor

applications

PhD Candidate: Hamideh KhanbarehDepartment: ASMSection: NovAMSupervisor: P. Groen and S. van der ZwaagPromoter: S. van der ZwaagStart date: 1-1-2012Funding: M2ICooperations: TNO

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Pyroelectricity is the ability of material to generate voltage upon a change in temperature. The materials are based on lead titanate (PT) perovskite ceramics with low dielectric constant compared to PZT. The pyroelectric figure of merit (FOM) is proportional to the pyroelectric coefficient, p(T), and inversely proportional to the relative dielectric permittivity.

Pyroelectric ceramics

Objective

Exploring the method of making oriented ceramic-polymer composites by dielectrophoresis for the class of pyroelectric materials and investigating the pyroelectric properties is the main aim of the current work.

Applications in sensors

SEM imagesDielectrophoresis

Structured

Random

10 vol.% ceramic 20 vol.% ceramic 30 vol.% ceramic

Results

Significant improvement in piezoelectric properties of composites is achieved by dielectrophoretic alignment of the particles inside the polymer matrix, especially at low volume fractions which leads to higher flexibility of the composites.

Highest

sensitivity

Light-weight and

flexible

PZT ceramicsPT-epoxy composites

Dielectric constant vs temperature Pyroelectric coefficient vs temperature

Fabrication of composites

Ceramic powder Epoxy resin Hardener

Electroding

Ceramic vol. %

Piez

o vo

ltage

con

stan

t (m

Vm/N

)

Conclusions