Elecroceramic-polymer
composites for sensor
applications
PhD Candidate: Hamideh Khanbareh
Department: ASM
Section: NovAM
Supervisor: P. Groen and S. van der Zwaag
Promoter: S. van der Zwaag
Start date: 1-1-2012
Funding: M2I
Cooperations: TNO
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.
Pyroelectric ceramics
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.
Fabrication of composites
Dielectrophoresis
SEM images
10 vol.% ceramic
Ceramic powder
Epoxy resin
20 vol.% ceramic
30 vol.% ceramic
Hardener
Random
Electroding
Structured
Results
PT-epoxy composites
PZT ceramics
Light-weight
and flexible
Piezo voltage constant (mVm/N)
Aerospace Engineering
Applications in sensors
Highest
sensitivity
Dielectric constant vs temperature
Pyroelectric coefficient vs temperature
Ceramic vol. %
Conclusions
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.